Answer: The compound which is not an empirical formula is [tex]C_2N_2H_8[/tex]
Explanation:
Empirical formula is defined as the formula in which atoms in a compound are present in simplest whole number ratios.
For the given options:
Option A: [tex]C_3H_8O[/tex]
This compound is made by the combination of carbon, hydrogen and oxygen. The mole ratio of the elements are [tex]C:H:O::3:8:1[/tex]
Option B: [tex]C_2N_2H_8[/tex]
This compound is made by the combination of carbon, hydrogen and nitrogen. The mole ratio of the elements are [tex]C:N:H::2:2:8[/tex]
This ratio can be reduced to lowest numbers. The empirical formula of this becomes [tex]C_{2/2}N_{2/2}H_{8/2}=CNH_4[/tex]
Option C: [tex]Sb_2S_3[/tex]
This compound is made by the combination of tin and sulfur atoms. The mole ratio of the elements are [tex]SB:S::2:3[/tex]
Option D: [tex]BeCr_2O_7[/tex]
This compound is made by the combination of beryllium, chromium and oxygen. The mole ratio of the elements are [tex]Be:Cr:O::1:2:7[/tex]
Hence, the compound which is not an empirical formula is [tex]C_2N_2H_8[/tex]
The high polarity of the oxygen-carbon bond in alcohols is what allows them to be soluble in water.
True
False
*please explain your answer for brainliest
This is false. An alcohol does indeed have a polar C-O single bond, but what we should really be focusing on is the extraordinarily polar O-H single bond. When oxygen, fluorine, or nitrogen is bound to a hydrogen atom, there is a small (but not negligible) charge separation, where the eletronegative N, O, or F has a partial negative charge, and the H has a partial positive charge. Water has two O-H single bonds in it (structure is H-O-H). The partially negative charge on the O of the water molecule (specifically around the lone pair) can become attracted either a neighboring water molecule's partially positive H atom, or an alcohol's partially positive H atom. This is weak (and partially covalent) attraction is called a hydrogen bond. This is stronger than a typical dipole-dipole attraction (as would be seen between neighboring C-O single bonds), and much stronger than dispersion forces (between any two atoms). When the solvent (water) and the solute (the alcohol) both exhibit similar intermolecular forces (hydrogen bonding being the most important in this case), they can mix completely in all proportions (i.e. they are miscible) in water.
Answer:
FalseExplanation:
Took test got it right.
Which statement best describes synthetic rubber?
A) Synthetic rubber is in limited supply compared with natural rubber
B) Synthetic rubber has the same properties as natural rubber
C) Synthetic rubber has different monomers than natural rubber
Answer:
C) Synthetic rubber has different monomers than natural rubber
Explanation:
Hello,
In this case, since statements A and B are correct due to the abundance of natural rubber and that both of them have the same properties making then suitable for several applications specially in the production of tires, belts, hoses, footwear and others, chemically, the best statement is C since the main monomers associated with synthetic rubber are derived from the petroleum byproducts such as styrene-butadiene whose condensation lead to the polymer forming the rubber. However, natural rubber is based on the isoprene (2-methyl-1,3-butadiene) as the promoting monomer whose polymerization lead to its formation.
Best regards.
read through the scenarios below and calculate the predicted change in kinetic energy of the object compared to a 50 kg ball traveling at 10 m/s.
a 50 kg ball traveling at 20 m/s would have _____ kinetic energy.
a 50 kg ball traveling at 5 m/s would have _____ kinetic energy.
a 50 kg ball traveling at 10 m/s would have _____ kinetic energy.
- the same
- 2 times more
- 2 times less
- 4 times more
- 4 times less
Explanation:
It is known that kinetic energy is half of mass times velocity square.
Mathematically, K.E = [tex]\frac{1}{2}mv^{2}[/tex]
where m = mass
v = velocity
The kinetic energy from which we have to compare shows that mass is 50 kg and v = 10 m/s.
Therefore, K.E = [tex]\frac{1}{2}mv^{2}[/tex]
= [tex]\frac{1}{2}50 \times 10^{2}[/tex]
= 2500 [tex]m/s^{2}[/tex]
1). K. E = [tex]\frac{1}{2}mv^{2}[/tex]
= [tex]\frac{1}{2}50 \times 20^{2}[/tex]
= 10000 [tex]m/s^{2}[/tex]
The object has 4 times more kinetic energy compared to a 50 kg ball traveling at 10 m/s.
2). K. E = [tex]\frac{1}{2}mv^{2}[/tex]
= [tex]\frac{1}{2}50 \times 5^{2}[/tex]
= 1250 [tex]m/s^{2}[/tex]
The object has 2 times less kinetic energy compared to a 50 kg ball traveling at 10 m/s.
3). K. E = [tex]\frac{1}{2}mv^{2}[/tex]
= [tex]\frac{1}{2}50 \times 10^{2}[/tex]
= 2500 [tex]m/s^{2}[/tex]
The object has the same kinetic energy compared to a 50 kg ball traveling at 10 m/s.
A researcher is using a particle accelerator in an expriment studying isotopes. How can the researcher change on isotope into a different isotope of the same element?
Neutron capture reactions.
ExplanationIsotopes of the same element have the same number of protons in each nucleus. However, their nucleus differ in the number of neutrons. Adding one or more neutrons to a nucleus will converts it to a different isotope of the same element.
Neutrons can be produced with a particle accelerator. The researcher might aim fast moving alpha particles [tex]\phantom{}_2^{4}\text{He}[/tex] from the accelerator at a beryllium Be target.
[tex]\phantom{}_4^{9} \text{Be} + \phantom{}_2^4\text{He} \to \phantom{}_{\phantom{1}6}^{12}\text{C} + \phantom{}_{0}^{1} \text{n}[/tex]
Doing so will convert beryllium-9 to carbon-12 and release one neutron.
The neutron produced in this process moves very fast ("fast neutrons"). It might knock protons or alpha particles off the target nucleus. This is undesirable since the nucleus will have a change in its proton number. It will end up belonging to a different element.
The researcher should reduce the speed of those neutrons. Passing neutrons through moderators greatly reduces their speed. Moderators are materials that are rich in light nuclei. They remove the energy of neutrons as the two collide. Examples of moderators are heavy water (D₂O) and graphite (carbon). Slow neutrons are easier to capture than fast-moving ones. Combining those slow-moving neutrons to the source isotope will likely produce a different isotope of the same element.
ReferenceVitz, Ed. et. al, "19.5: Neutron Bombardment", ChemPRIME (Moore et al.), Libretexts Chemistry, 2017
Answer:
D. BY ADDING OR REMOVING NEUTRONS.
Hope this helps!
Explanation:
what is a photoelectric?explain the terms ground state and excited state with the help of labelled diagram
Answer: Photoelectric is characterized by or involving the emission of electrons from a surface by the action of light.
Photoelectric effect is the emission of electrons when a radiation of frequency higher than the threshold frequency falls on the surface of an element. The substance which undergoes photoelectric effect is called as photoelectric.
Ground state is the state representing the lowest energy state.
Excited state is the state which represents a high energy state.
An electron in ground state absorbs energy to move to the excited state.
How many moles of Fe3O4 would be produced if 0.500 mol of H2O is reacted fully?
.125mol Fe3O4.
To find this, you need to create a molar ratio.
Reference the image to see what this looks like.
Once you have the ratio set, cross the same and multiply across before dividing what's on the bottom.
Hope this helps!
Hydrogen bonding occurs in molecules when a _____________. (1 point)
hydrogen atom forms a covalent bond with one other atom.
hydrogen atom forms covalent bonds with more than one atom.
hydrogen atom of a polarized molecule bonds with an electronegative atom
hydrogen atoms form an ionic bond with one other atom
Answer: hydrogen atom of a polarized molecule bonds with an electro negative atom.
Explanation:
Hydrogen bonds are special type of dipole dipole forces which are formed when hydrogen bonds with an electro negative element. Hydrogen bonds are strongest type of bonds .Example: Bond between Oxygen of one water molecule to the hydrogen of another water molecule as shown in the image below.
Covalent bonds are formed by sharing of electrons among non metals.
Ionic bond is formed by transfer of electrons between metals and non metals.
List the 3 mole equalities.
I am not sure if this is what you are looking for, I have done a bit searching.
1 mol = 6..20 x 103 particles (atoms, molecules, formula units)
1 mol = molar mass/formula mass (Periodic Table)
1 mo = 22.4 L for a ga at STP
The three mole equalities are 1 mole = 6.20 x 103 particles,1 mole = molar mass/formula mass 1 mole = 22.4 L for a gas at STP.
What is a mole?
Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
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16. Representative elements are those found in the *
A. s and p blocks
B. d block
C. s and d blocks
D. d and f blocks
17. Within the representative elements, atomic size generally *
A. Remains constant within a period
B. Increases as you move left to right across an energy level
C. Increases as you move down a group
D. Cannot be predicted
18. Ions are charged particles formed from atoms. Which of these would be true? *
A. Cations form when an atom gains electrons.
B. Cations form when an atom loses electrons.
C. Anions form when an atom gains protons.
D. Anions form when an atom loses protons.
What is the molarity of 500 ml of a solution containing 85.0g AgNO3? A) 0.5 M B) 1.0 M C) 2.0 M D) 5.0 M
Consider the equation for calculating molarity: (no. of mole of solute)÷(volume of solution)
First, let's find the no. of mole of solute in AgNO3. As (no. of mole) = mass / molar mass
no. of mole of 85.0g of AgNO3 = 85.0/(107.9+14.0+16.0x3)
=0.5mol
Since the volume of the solution has to be in dm3, just divide the volume in cm3 by 1000 to get the volume in dm3.
Volume of solution = 500/1000
= 0.5 dm3
Therefore, the molarity is
0.5/0.5
=1.0M
The answer should be B.
How can rainfall affect the mineral content of ocean water?
Salinity. Although everyone knows that seawater is salty, few know that even small variations in ocean surface salinity (i.e., concentration of dissolved salts) can have dramatic effects on the water cycle and ocean circulation. ... The weathering of rocks delivers minerals, including salt, into the ocean.
Answer:
salinity
Explanation:
what are Silvery metals ,Soft Highly reactive metals too reactive to be found free in nature, Low melting and boiling temperatures, Low densities called
You might be referring to alkali metals.
ExplanationAlkali metals are in group 1 of the periodic table.
Alkali metals have a silvery color. Like nearly all main group metals, they reflect light from the entire visible spectrum.
Each of the group 1 atom have one single valence electron. Removing that electron is easy. They are one electron away from the nearest noble gas element. Removing that extra electron will give the atom an empty valence shell. The atom gains stability through that process.
Alkali metals will readily lose its electrons to non-metals such as oxygen, chlorine, and fluorine. They react with water to form a base and hydrogen gas- hence the name alkali. They are too reactive to exist in nature as metals. That's one of the reasons why power packs containing lithium (an alkali metal) should not be cut open at home. They might catch fire when exposed to the air and have a good chance of creating an explosion.
Alkali metals have low m.p. and b.p. among all the metals. They are easy to cut under room temperature. The softness (a.k.a. malleability), melting point, and boiling point of a metal depends on the strength of the bond between its atoms. Each of the group 1 alkali metal atom has one single electron, whereas metals like aluminum have three. Metallic bonds between alkali metal atoms are much weaker than those between aluminum atoms. As a result, it takes less energy to pull alkali metal atoms apart. They are easier to melt, boil, or cut than metals from other groups. For example, it is possible to tear a chunk of sodium but not iron apart by hand.
Alkali metals are likely to be less dense than any other metals on the periodic table. Elements from the same period have an equal number of electron shells. Alkali metals have less protons per atom than elements from the rest of the period. They weakly attract their electron shells and have a large atomic and ionic radius. An alkali metal will have a lofty structure, while metals to the right of the period are more tightly packed. Alkali metals will have less mass per unit space and have a lower density. For example, typical power banks contain lithium ions rather than nickel. Lithium is lighter than nickel; it allows the battery pack to store more energy per unit mass.
Alkali metals are silvery, soft, highly reactive elements with low melting and boiling points, and are found in Group 1 of the periodic table. These include lithium, sodium, potassium, rubidium, cesium, and francium.
Explanation:The silvery metals that are soft, highly reactive, and too reactive to be found free in nature, characterized by low melting and boiling temperatures, and low densities, are known as alkali metals. These elements make up Group 1 of the periodic table and include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Alkali metals react rapidly with water to form hydroxides and hydrogen gas, and they must be stored under oil to prevent reactions with moisture and oxygen from the air.
Their reactivity is due to having one electron in their outermost energy level, which they can easily lose to form positive ions with a charge of +1.
If 27.1 g of ar(g) occupies a volume of 4.21 l, what volume will 1.29 moles of ne(g) occupy at the same temperature and pressure?
Answer : The volume of neon gas will be, 7.99 liters.
Explanation : Given,
Mass of argon (Ar) gas = 27.1 g
Molar mass of argon = 39.95 g/mole
Volume of argon gas = 4.21 L
Moles of neon (Ne) gas = 1.29 mole
First we have to calculate the moles of argon gas.
[tex]\text{Moles of }Ar=\frac{\text{Mass of }Ar}{\text{Molar mass of }Ar}=\frac{27.1g}{39.95g/mole}=0.68moles[/tex]
Now we have to calculate the volume of neon gas.
According to the Avogadro's law, the volume of gas is directly proportional to the number of moles of gas at same pressure and temperature. That means,
[tex]V\propto n[/tex]
or,
[tex]\frac{V_1}{V_2}=\frac{n_1}{n_2}[/tex]
where,
[tex]V_1[/tex] = volume of argon gas
[tex]V_2[/tex] = volume of neon gas
[tex]n_1[/tex] = number of moles of argon gas
[tex]n_2[/tex] = number of moles of neon gas
Now we put all the given values in this formula, we get
[tex]\frac{4.21L}{V_2}=\frac{0.68mole}{1.29mole}[/tex]
[tex]V_2=7.99L[/tex]
Therefore, the volume of neon gas will be, 7.99 liters.
Match the following vocabulary terms to their definitions. 1 . amount of energy required to change 1 gram of material from the solid to the liquid state at its melting point temperature 2 . a measure of the kinetic energy of the particles of a substance latent heat of vaporization 3 . the amount of energy required to change 1 gram of a substance 1°C latent heat of fusion 4 . amount of energy required to change 1 gram of material from the liquid to the gaseous state at its boiling point calorie 5 . the amount of heat energy required to raise the temperature of 1 gram of liquid water from 14.5°C to 15.5°C specific heat
1) amount of energy required to change 1 gram of material from the solid to the liquid state at its melting point - latent heat of fusion.
The temperature at which the phase transition occurs is the melting point or the freezing point.
2) a measure of the kinetic energy of the particles of a substance - temperature.
Temperature is the intensity of heat present in a substance and a thermometer is a device that measures temperature or a temperature gradient.
3) the amount of energy required to change 1 gram of a substance 1°C - specific heat.
Heat capacity of a sample is expressed in units of thermal energy per degree temperature (J/K).
Heat capacity is often defined relative to a unit of mass (J/kg·K or J/g·K), prefixed with the term specific.
For example, specific heat capacity of water is 4.184 J/g·K (Cp(H₂O) = 4.184 J/g·K).
4) amount of energy required to change 1 gram of material from the liquid to the gaseous state at its boiling point - latent heat of vaporization.
For example, evaporization is phase change process in which the water changes from a liquid to a gas (water vapor). Solar radiation is the source of energy for evaporation.
5) the amount of heat energy required to raise the temperature of 1 gram of liquid water from 14.5°C to 15.5°C - calorie.
Calorie (cal), or small calorie, is the amount of energy needed to heat one gram of water by one degree Celsius.
One small calorie is approximately 4.2 joules.
A calorie is a unit of energy.
Bruce left some butter out in his kitchen. Bright sunlight came in through the window and melted the butter. Heat energy from the sun is called A) conduction. B) convection. C) insulation. D) radiation.
Answer:
D) is the correct answer on usatestprep
Explanation:
An object exerts force of 500 n and sits on an area of 4.5m X 1.5m. Calculate the amount of pressure exerted by the object in torr.
Final answer:
The pressure exerted by the object is 0.556 torr.
Explanation:
To calculate the pressure exerted by an object, we use the formula:
Pressure = Force / Area
In this case, the force exerted by the object is 500 N and the area it covers is 4.5 m x 1.5 m = 6.75 m². So the pressure exerted by the object can be calculated as:
Pressure = 500 N / 6.75 m² = 74.07 Pa
Since the question specifically asks for the pressure to be calculated in torr, we need to convert Pa to torr. 1 Pa = 0.00750062 torr, so:
Pressure in torr = 74.07 Pa * 0.00750062 torr/Pa = 0.556 torr
As the vibration of molecules increase, the_______ of the substance increases
the temperature, internal energy and kinetic energy
Write a balanced net ionic equation for the following reaction. Explain how you arrived at this answer. What did you cancel out? AgNO^3 (aq) + KCI (aq) ----> AgCI (s) + KNO^3 (aq)
The net ionic equation is
Ag⁺(aq) +Cl⁻(aq) → AgCl(s)
Explanation
AgNO₃ (aq) + KCl (aq)→ AgCl(s) +KNO₃(aq)
from above molecular equation break all soluble electrolyte into ions
Ag⁺(aq) +NO₃⁻ (aq) + K⁺(aq) +Cl⁻(aq) → AgCl (s) + K⁺(aq) + No₃⁻(aq)
cancel the spectator ions in both side of equation =K⁺ and NO₃⁻ ions
The net ionic equation is therefore
= Ag⁺(aq) + Cl⁻(aq) → AgCl(s)
The net ionic equation for the reaction AgNO₃(aq) + KCl(aq) ---> AgCl(s) + KNO₃(aq) is Ag+(aq) + Cl-(aq) ---> AgCl(s), which is found by first writing the complete ionic equation and then canceling the spectator ions, which appear on both sides of the reaction.
Explanation:The process of writing a balanced net ionic equation involves several steps. Firstly, the complete ionic equation needs to be written which looks like this: Ag⁺(aq) + NO₃⁻(aq) + K⁺(aq) + Cl⁻(aq) ---> AgCl(s) + K+(aq) + NO₃⁻(aq). After that, we find the spectator ions that appear on both sides of the reaction. In this case, they are K+(aq) and NO₃⁻(aq). We then cancel out these spectator ions to get the net ionic equation, which is: Ag+(aq) + Cl-(aq) ---> AgCl(s). Essentially, these equations show the salts splitting into their ions if they are soluble in water (indicated by (aq)), and then recombining to form the precipitate (s).
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what is the formula of calculating density?
density = mass/volume
Answer:
Why is volleyball considered to be such a good aerobic exercise?
Explanation:
When radioactive carbon (C-14) decays, it produces an isotope of nitrogen (N-14) and emits a beta particle. Which symbol seen above represents a beta particle?
14/6 C --> 0/-1 e + 14/7 N
Either an electron or the symbol can be used to represent the beta particle.
What transpires when carbon-14 breaks down into nitrogen-14?When carbon-14 decays into nitrogen-14, a process known as beta decay takes place. One of the neutrons in the carbon atom turns into a proton during this process, which results in the decay of a 14C atom into a 14N atom.
By adding one more proton to the atom, this results in the formation of a nitrogen atom rather than a carbon atom.
Beta decay of carbon-14 results in the release of one electron. The final product is a nucleus with seven protons and seven neutrons. As bizarre as it may sound, this indicates that one of the neutrons
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Final answer:
The symbol representing a beta particle emitted during radioactive decay of carbon-14 is the Greek letter ß, also represented as e- or ß-. This particle is a high-speed electron ejected from the nucleus, resulting in the formation of a nitrogen-14 nucleus.
Explanation:
When radioactive carbon (C-14) decays, it produces nitrogen-14 (N-14) and emits a beta particle. The symbol that represents a beta particle is the Greek letter ß. However, a beta particle can also be represented as an electron with a -1 charge, which is symbolized by e- or ß- in nuclear equations.
The beta particle is essentially a high-speed electron that's ejected from the nucleus during radioactive decay, and this process turns a neutron into a proton within the nucleus, increasing the atomic number by one while the mass number remains unchanged. The beta particle's emission is critical in the decay process of carbon-14, which is widely used in radioactive dating techniques.
How much heat energy is required to melt 75g of ice at 0°C?
a. 4.45J
b. 30.13J
c. 169, 500J
d. 25, 050J
The enthalpy change for melting ice is called the entlaphy of fusion. Its value is 6.02 kj/mol. This means for every mole of ice we melt we must apply 6.02 kj of heat. We can calculate the heat needed with the following equation:
Q = N x ΔH
where:
Q = heat
N = moles
ΔH = enthalpy
In this problem we would like to calculate the heat needed to melt 35 grams of ice at 0 °C. This problem can be broken into three steps:
1. Calculate moles of water
2. multiply by the enthalpy of fusion
3. Convert kJ to J.
Step 1 : Calculate moles of water
[tex][ 75g ] x (\frac{1 mol}{18.02g} ) =[/tex]
Step 2 : Multiply by enthalpy of fusion
Q = N × ΔH = [ Step 1 Answer ] × 6.02 =
Step 3 : Convert kJ to J
[tex][ Step 2 Answer ] x (\frac{1000j}{1kJ} ) =[/tex]
Finally rounding to 2 sig figs (since 34°C has two sig figs) we get
Q Would Equal ____
The correct option is d. 25, 050J of heat energy is required to melt 75g of ice at 0°C.
The mass of the ice given is 75g. To find the amount of heat energy required to melt this ice, we multiply the mass of the ice by the specific latent heat of fusion of water:
[tex]\[ Q = m \cdot L \][/tex]
Using the values provided:
[tex]\[ Q = 75 \text{g} \cdot 334 \text{J/g} \] \[ Q = 25,050 \text{J} \][/tex]
However, this value represents the heat energy required to melt 75g of ice into water at the same temperature (0°C). Since the ice is already at 0°C, we do not need to consider the energy required to raise its temperature from a lower value to 0°C.
Now, let's look at the options provided in the question:
a. 4.45J: This is the energy required to raise the temperature of 1g of water by 1°C, which is not relevant to the melting process.
b. 30.13J: This is a small amount of energy and seems incorrect for melting 75g of ice.
c. 169,500J: This value is likely a misinterpretation of the correct calculation, as it could be the result of multiplying the mass of the ice by the specific latent heat of vaporization (which is about 2257 J/g for water), not fusion.
d. 25,050J: This is the correct amount of heat energy required to melt 75g of ice at 0°C, as calculated above.
Which options correctly describe characteristics of noble gases? Select all that apply.
All noble gases easily react with other elements.
All noble gases have valence shells with 8 electrons.
All noble gases have a unique atomic fingerprint.
All noble gases emit pink light when electrified.
This is the only option that correctly describe characterisitics of noble gases.
All noble gases have a unique atomic fingerprint.
All noble gases have valence shells with 8 electrons but Heilum has only 2 valence electrons.
And all noble gases do not easily react with other elements as they have their outermost shell completly filled so they are highly stable.
All noble gases emits different colored light when electrified.
Noble gases have valence shells with 8 electrons and a unique atomic fingerprint. They do not easily react with other elements and emit different colors of light when electrified.
Explanation:Noble gases are a group of chemical elements that have certain characteristic properties. Two options that correctly describe the characteristics of noble gases are:
All noble gases have valence shells with 8 electrons. This is known as the octet rule, which states that atoms tend to gain, lose, or share electrons to achieve a stable configuration of 8 valence electrons.All noble gases have a unique atomic fingerprint. Each noble gas has a distinct set of energy levels and electron configurations, which result in unique spectral lines when the gas is energized.One misconception in the given options is that all noble gases easily react with other elements. In fact, noble gases are known for their low reactivity due to their stable electron configurations and full valence shells.
The option stating that all noble gases emit pink light when electrified is also incorrect. While noble gases do emit light when an electric current is passed through them, the color of the emitted light varies for each gas. For example, argon emits a violet glow, neon emits red-orange, and helium emits a yellowish-orange glow.
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Some chemical reactions absorb energy rather than release it. Which of these phenomena are caused by chemical reactions that absorb energy? If you're not sure, make a guess
A chemical reaction absorbs energy which means it is endothermic reaction.
The reaction is endothermic if the energy of products is more than the energy of reactants.
The energy of products is more means that the bond energy of products is more than the bond energy of reactants.
so breaking of bond needs energy which is greater than the energy released in making of new bonds.
Enthalpy of reaction = Bond energy of reactants - Bond energy of products.
Answer:
its all of them
Explanation:
i got it off of edmentum
why is the Pacific Northwest receives so much precipitation?
The Cascades rain shadow can be described as such: ocean-influenced moist air masses are forced to rise when they meet the tall moun- tains. The rising air cools, condenses, and the moisture falls as precipitation. On the leeward (dry) side of the mountain, the now dry air warms and sinks.
Answer: The high amount of humidity explains the impressive amount of rain that falls on the Pacific.
Explanation:
In the Pacific Northwest there is a wind current that travels from west to east. It enters the continent and hits a mountain range in a process called "orographic ascent". The jet ascends, the humidity condenses, and the winds coming from the east meet in the opposite direction with this current and push the clouds. That is why the rains are so strong on the Pacific coast. The high amount of humidity explains the impressive amount of rain that falls on the Pacific. When this moist wind blows inland, the moist air may rise into the atmosphere enhancing the clouds and strady rainfall.
Water evaporates from the ocean and is carried over the Northwest , where it cools and condense into the rain.
There is also a low-pressure systems at the surface which is the driving force that produce rain and winds and this allows large storms to crash into the coast with ease. Some of these storms can be enormous and can cause significant wind damage and flooding.
Give the correct thermochemical equations for a (cacl2+h2o) pack and (nh4no3+h2o) pack.
Explanation: A thermochemical equation is a balanced chemical equation which require an enthalpy change.
A balanced equation is the equation in which number of atoms on reactant side is same as the number of atoms on product side.
A thermochemical equation for [tex]CaCl_2+H_2O[/tex] is:
[tex]CaCl_2+2H_2O\rightarrow Ca(OH)_2+2HCl+heat[/tex]
Here, heat is released in the reaction hence, it is a type of exothermic reaction.
A thermochemical equation for [tex]NH_4NO_3+H_2O[/tex] is:
[tex]NH_4NO_3+heat\overset{water}{\rightarrow} NH_4^++NO_3^-[/tex]
Here, heat is absorbed in the reaction hence,it is a type of endothermic reaction.
The salts NaCl and CaCl2
(a) are good conductors of electricity
(b) have positive charges
(c) have the same crystal lattice of energy
(d) are held together by ionic bond
Only (d) appears to be correct.
ExplanationNaCl and CaCl₂ are ionic compounds. Both are made up of charged particles known as ions.
NaCl contains Na⁺ ions and Cl⁻ ions.CaCl₂ contains [tex]\text{Ca}^{2+}[/tex] ions and Cl⁻ ions.Na⁺ and [tex]\text{Ca}^{2+}[/tex] are cations. They carry positive charges.Cl⁻ is an anion. It carries a negative charge.Opposite charges attract each other. So is the case between cations and anions. The two kinds of ions attract each other to produce an ionic lattice. Forces holding them together are known as ionic bonds.
Cations and anions pair up in an ionic compound. Their charges cancel out such that the final compound is neutral. Charged species shall always have a superscript in their formulae that indicates their charge. For example, [tex]\text{Ca}^{2+}[/tex] has positive charges. As a result, it comes with a superscript of "2+". Neither NaCl nor CaCl₂ has a superscript. They are both neutral.
The molar lattice enthalpy of an ionic compound measures the energy released when one mole of it was formed from gaseous ions. This value depends on the size and charge of each ion.
Each mole of CaCl₂ carry four times as much charge as NaCl and three time as much ions. CaCl₂ is expected to have a much higher molar lattice enthalpy.
FYI, the molar lattice enthalpy of NaCl is about -787 kJ/mol (Chemguide). The value for CaCl₂ is -2255 kJ/mol (ACS).
The salts NaCl and CaCl2 are held by ionic bonds. They do not conduct electricity in their solid state, but do so once dissolved or melted. They contain positive and negative ions and do not have the same crystal lattice of energy.
Explanation:The salts NaCl and CaCl2 are indeed held together by ionic bonds, which are electrostatic forces of attraction between oppositely charged ions. These compounds, like many ionic solids, do not conduct electricity in their solid state as the strength of ionic bonds prevents ions from moving freely. However, once they dissolve in water or melt, they become excellent conductors of electricity because the ions can move freely, becoming electrolytes capable of conducting electricity. This is why the statement 'NaCl and CaCl2 are good conductors of electricity' applies only when these compounds are dissolved or melted.
The ions in ionic compounds like NaCl and CaCl2 do carry positive (for metal ions) and negative charges (for non-metal ions). They do not, however, all carry positive charges as suggested in the second part of your question. Lastly, while it is true that all ionic compounds form a crystalline structure due to the orderly arrangement of their ions, this does not imply that all ionic compounds have the same crystal lattice of energy. The exact structure and energy can variate between different ionic compounds.
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PLEASE HELP!!! 10 POINTS
Melinda's science teacher gave her an unknown substance to identify based on its properties. After a few tests, Melinda listed her observations in a chart.
reflects light very well
warms up in my hand
flattens out when hit with a hammer
conducts electricity
Which kind of substance does Melinda have?
A. nonmetal
B. metal
C. metalloid
The unknown substance that Melinda is encountering in her experiment is most likely a metal, based on its ability to reflect light, warm up in the hand, flatten upon impact, and conduct electricity. These are all characteristic properties of metals.
Explanation:Based on the properties of the substance highlighted by Melinda - the ability to reflect light, warm up in the hand, flatten out when hit with a hammer, and conduct electricity - it suggests that she is dealing with a metal. These are standard characteristics of metals, which are usually shiny (reflect light), malleable (can be flattened), conductive to heat and electricity, and are known to warm up when handled due to their conductivity.
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Question 14 A student dissolves 1.5g of styrene C8H8 in 225.mL of a solvent with a density of 1.02/gmL . The student notices that the volume of the solvent does not change when the styrene dissolves in it. Calculate the molarity and molality of the student's solution. Round both of your answers to 2 significant digits. molarity = molality = Ă—10
We must to know:
Cm = molarity = niu / Vs, when the niu = no. of moles and Vs = Volume of solution
the no. niu = mass / molecular mass of substance
molecular mass of C8H8 = 12x8+8x1 = 104 g/mol
=> niu = 1,5 / 104 = 0,0144 moles C8H8
=> Cm = 0,0144/0,225 = 0,06 mol/L
Cmm = molality = niu (C8H8) / mass of solvent (kg)
=> p = mass / V => mass (solvent) = p x V
=> 225 x 1,02 = 229,5 g solvent = 0,2295 kg solvent
=> Cmm = 0,0144 / 0,229,5 = 0,063
Answers:
a. 0.064 mol/L; b. 0.063 mol/kg
Explanation:
a. Molar concentration
c = moles/litres
=====
Moles = 1.5 × 1/104.15
Moles = 0.0144 mol
=====
Litres = 225. × 1/1000
Litres = 0.225. L
=====
c = 0.0144/0.225.
c = 0.064 mol·L⁻¹
===============
b. Molal concentration
b = moles of solute/kilograms of solvent
=====
Mass of solvent = 225. × 1.02/1
Mass of solvent = 229.5 g Convert to kilograms
Mass of solvent = 0.2295 kg
=====
b = 0.0144/0.2295
b = 0.063 mol/kg
PLEASE HELP! 25 POINTS!!!! I got the #1, just not #2 and #3. An industrial chemical company has opened a new plant that will produce ammonia (NH3). Hydrogen and nitrogen gases are reacted to produce the ammonia. For the first batch of ammonia production, 475 g of nitrogen is reacted with excess hydrogen, and 397 g of ammonia are produced.
• Write the balanced equation for the formation of ammonia from hydrogen and nitrogen.
[tex]3Hx_{2} + Nx_{2} --\ \textgreater \ 2NHx_{3}[/tex]2NH3
• Calculate the theoretical yield of ammonia. Work must be shown to earn credit.
• Calculate the percent yield for the ammonia production. Work must be shown to earn credit.
Answer :
Part 1 : Balanced reaction, [tex]3H_2(g)+N_2(g)\rightarrow 2NH_3(g)[/tex]
Part 2 : The theoretical yield of [tex]NH_3[/tex] gas = 440.96 g
Part 3 : The % yield of ammonia is 90.03 %
Solution : Given,
Mass of [tex]N_2[/tex] = 475 g
Molar mass of [tex]N_2[/tex] = 28 g/mole
Molar mass of [tex]NH_3[/tex] = 17 g/mole
Experimental yield of [tex]NH_3[/tex] = 397 g
Answer for Part (1) :
The balanced chemical reaction is,
[tex]3H_2(g)+N_2(g)\rightarrow 2NH_3(g)[/tex]
Answer for Part (2) :
First we have to calculate the moles of [tex]N_2[/tex].
[tex]\text{Moles of }N_2=\frac{\text{ Mass of }N_2}{\text{ Molecular mass of }N_2}=\frac{475g}{28g/mole}=16.96moles[/tex]
From the given reaction, we conclude that
1 moles of [tex]N_2[/tex] gas react to give 2 moles of [tex]NH_3[/tex] gas
16.96 moles of [tex]N_2[/tex] gas react to give [tex]\frac{2}{1}\times 16.96=33.92[/tex] moles of [tex]NH_3[/tex] gas
Now we have to calculate the mass of [tex]NH_3[/tex] gas.
[tex]\text{ Mass of }NH_3=\text{ Moles of }NH_3\times \text{ Molar mass of }NH_3[/tex]
[tex]\text{ Mass of }NH_3=(33.92moles)\times (17g/mole)=440.96g[/tex]
Therefore, the theoretical yield of [tex]NH_3[/tex] gas = 440.96 g
Answer for Part (3) :
Formula used for percent yield :
[tex]\% \text{ yield of }NH_3=\frac{\text{ Experimental yield of }NH_3}{\text{ Theoretical yield of }NH_3}\times 100[/tex]
[tex]\% \text{ yield of }NH_3=\frac{397g}{440.96g}\times 100=90.03\%[/tex]
Therefore, the % yield of ammonia is 90.03 %
Which of these statements about resonance is true? (a) when you draw resonance structures, it is permissible to alter the way atoms are connected. (b) the nitrate ion has one long n—o bond and two short n—o bonds. (c) "resonance" refers to the idea that molecules are resonating rapidly between different bonding patterns. (d) the cyanide ion has only one dominant resonance structure. (e) all of the above are true?
Final answer:
The correct statement about resonance is that the cyanide ion has only one dominant resonance structure. Resonance structures represent the average distribution of electrons without changing the connectivity of atoms, and the true structure of a molecule is a hybrid of all resonance forms. So the correct option is d.
Explanation:
The correct statement about resonance is (d) the cyanide ion has only one dominant resonance structure. Resonance refers to the concept where the actual distribution of electrons in a molecule or polyatomic ion cannot be represented by a single Lewis structure; instead, it is best represented by two or more resonance structures which are averages of each other. It is important to note that when drawing resonance structures, the connectivity of atoms should not change, meaning altering the way atoms are connected is not permissible. Nitrate ion (NO3-), as another example, has resonance forms with equivalent bond lengths due to resonance, contradicting the statement that it has one long N—O bond and two short N—O bonds. It is a misconception to think that a molecule resonates rapidly between different bonding patterns; rather, the true structure is a hybrid that does not change from one form to another but is the average of the resonance forms.