Only half of the moon is lit up as it makes its revolution around the earth.
Explanation:The surface of the moon reflects the light incident from the sun and that is what makes the moon bright and shiny. While making its revolution around the earth, whatever is its position in the trajectory, only half of its entire surface is facing the sun and thus only half of the moon is lit up; the other half is always on the shadow side.
What accounts for the differed brightness and shapes as observed from the earth is its position with respect to earth and the sun and this changes each day. When the sun, the earth and the moon all are in a straight line, the moon appears to be the brightest giving a Full moon and when it is between the sun and earth, the lit side is facing opposite to earth and thus it is not visible to us; giving rise to a New moon.
5. Which of the following correctly shows alpha decay?
ABU --> Ra + Be
a U --> NP + Be
can U --> Th + He
D ESU --> Pu + He
Answer:
U --> Th + He
Explanation:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴
How is "food" produced in ecosystems without sunlight?
Question 14 options:
A. by chemosynthesis
B. by photosynthesis
C. by phytoplankton
D. by autosynthesis
Final answer:
Food in ecosystems without sunlight is produced through chemosynthesis, a process where chemoautotrophs convert inorganic compounds into organic matter, supporting various deep-sea organisms.
Explanation:
The production of food in ecosystems without sunlight is primarily achieved through a process known as chemosynthesis. Chemosynthesis is the biological conversion of one or more carbon-containing molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic compounds (such as hydrogen sulfide or ammonia) as a source of energy, rather than sunlight, as in photosynthesis. This process is utilized by a specialized group of bacteria, known as chemoautotrophs. Option A
Chemoautotrophs are commonly found in extreme environments, such as hydrothermal vents on the ocean floor. Here, they synthesize organic compounds by harnessing the energy from chemical reactions involving inorganic molecules, which are abundant in these regions. This in turn supports a diverse ecosystem, with organisms like tubeworms, crustaceans, and octopuses that rely on these bacteria for their own energy needs.
Which element is the reducing agent in a redox reaction?
O
A. The reactant that has the atom that gets oxidized
O
B. The product that has the atom that was oxidized
C. The reactant that has the atom that gets reduced
O
D. The product that has the atom that was reduced
SUBMI
Answer:
The reactant that has the atom that gets oxidized
Explanation:
A redox reaction is a reaction in which one substance is oxidized and one is reduced. The easiest way to remember the patterns of any redox reaction is to follow a simple abbreviation: OILRIG.
This acronym stands for: oxidation is loss, reduction is gain (of electrons). Therefore, if a substance is oxidized, then it loses electrons. If a substance is reduced, it gains electrons.
Let's take a look at the following example:
[tex]Cu (s) + 2 Ag^+ (aq)\rightarrow Cu^{2+} (aq) + 2 Ag (s)[/tex]
Notice that copper loses two electrons, as it becomes positively charged:
[tex]Cu (s)\rightarrow Cu^{2+} (aq) + 2e^-[/tex]
Since electrons are on the right-hand side, it means we produce them (they are lost). Hence, copper in this equation is oxidized. Similarly:
[tex]Ag^+(aq)+e^-\rightarrow Ag(s)[/tex]
Now, silver cation gains electrons to become solid silver, neutrally charged, meaning it is reduced.
In terms of an oxidizing/reducing agents, the thought process is opposite: in an oxidation process, we have a reducing agent, hence, Cu (s) is our reducing agent. In a reduction process, we have an oxidizing agent, hence, silver cation is our oxidizing agent.
Both reducing and oxidizing agents are reactants.
Therefore, reducing agent is a reactant that has the atom that gets oxidized.
Answer: A
Explanation:
a p e x
1. According to the fossil record, the first LAND plants were most likely pine trees. moss and ferns. flowering plants. 2. Scientists have found fossils of pine cones, seeds, and leaves with veins. More than likely scientists would also find fossilized remains of fish. dinosaurs. mammals 3. Lots of shell fossils and no plant fossils tell us that Earth probably mostly covered with oceans and little dry land. true
Answer:
It is true that earth was once covered with oceans and little dry land.
Explanation:
Over the course of around four billion years, the Earth's oceans have lost about a quarter of their original mass. Today the atmosphere is rich in oxygen, which reacts with both hydrogen and deuterium to recreate water, which falls back to the Earth's surface. So the vast bulk of the water on Earth is held in a closed system that prevents the planet from gradually drying out. According to the researchers, the continents emerged relatively suddenly from an ocean that covered 95 percent of the Earth's surface. The appearance of large masses of dry land would have caused more extreme weather, changes in ocean currents and the emergence of proper seasons. In turn, these environmental changes may have led to rise in atmospheric oxygen that enabled the explosion of new life forms around 500 million years ago.
Answer:
Explanation:
`1. Moss and ferns
2. Mammals
3. True
Which of these is associated with the kinetic energy of electricity?
A.waves in fluids
B.moving electrons
C.the position of magnets
D.vibration of ions
Answer:
B.
Explanation: hoped i helped =O
vocab; i don’t remember the answers :(
Answer:
7. The higher the temperature is something the greater it's Thermal energy
8. The Change in state from gas to liquid is called Condensation
9. Energy that comes from bonds within matter us called Chemical reaction
10. The change in state from liquid to has is called Vaporization
11. Gas bubbles forming through out the liquid is called Boiling
12. Liquid changing to gas only at the surface is called Evaporation
13. The change in state from a solid to a liquid is called Melting
14. The change in state from a liquid to solid is called Freezing
15. The Law of conservation of energy states that during any change, the amount of energy stays the same.
16. Another term for a chemical change is a Chemical energy
17. In Sublimation particles pass directly from solid to gas.
Explanation:
Answer:
7) Thermal energy, 8) Condensation, 9) Chemical energy, 10) Vaporization, 11) boiling, 12) evaporation, 13) melting, 14) freezing, 15) Law of Conservation of Energy, 16) chemical reaction, 17) sublimation.
Explanation:
7) The higher the temperature of something, the greater its thermal energy.
8) The change in state from gas to liquid is called condensation.
9) Energy that comes from bonds within matter is called chemical energy.
10) The change in state from liquid to gas is called vaporization.
11) Gas bubbles forming throughout the liquid is called boiling.
12) Liquid changing to gas only at the surface is called evaporation.
13) The change in state from solid to liquid is called melting.
14) The change in state from liquid to solid is called freezing.
15) The Law of Conservation of Energy states that during any change, the amount of energy stays the same.
16) Another term for a chamical change is a chemical reaction.
17) In sublimation, particles pass directly from solid to gas.
Sudden heavy rains cause what kind of conditions that can then cause flooding
Constant and heavy raining can cause the drains to overflow and build up in large puddles.
I have no idea if this is what you were looking for or not.
Answer:
Saturated ground and poor drainage
Explanation:
I did usa prept
A sugar cube in a test tube is heated over a Bunsen burner. The sugar cube turns black and has
less mass than before it was heated. These changes occur because the sugar has-
A.become hydrated
B.reacted chemically
C.melted
D.boiled
Answer:
The correct answer is B reacted chemically.
Explanation:
When a sugar cube in a test tube is heated over a bunsen burner the sugar cube turns back because the heat that is generated by the Bunsen burner dehydrate the sugar molecule.
As a result the sugar molecule lost water from its chemical structure which causes the sugar molecule to turn black.As water molecules are lost from the sugar the mass of the sugar molecule is being decreased from its original or primary mass.
In general the sugar molecule undergo dehydration reaction which is responsible for the black coloration of the sugar as well asw los of mass from the sugar molecule.
The sugar cube has undergone a chemical reaction, known as caramelization, when heated over a Bunsen burner. This reaction causes the sugar to turn black and release gases, which reduces its overall mass. The heat change from the Bunsen burner contributes to this chemical process.
Explanation:When a sugar cube is heated over a Bunsen burner and turns black, it is due to a chemical reaction happening. This process is known as caramelization, where the heat breaks down the sugar molecules into other compounds. This reaction, unlike dissolving sugar in water, is not a physical but a chemical change because it alters the sugar's composition and it cannot be reversed.
The fluffy black mass that forms does indeed have less mass than the original sugar cube. This reduction in mass is due to the release of water vapor and carbon dioxide during the process. These gases escape into the air, lowering the overall mass of the end product.
The heat from the Bunsen burner contributes to this chemical reaction. The heat comes from the combustion reaction of methane under roughly constant atmospheric pressure, making enthalpy a convenient choice for determining the heat changes for such chemical reactions.
Therefore, the correct answer to your question is that the sugar cube has 'reacted chemically' (option B).
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How do you convert Pa*mm^2 to Pa*m^2?
Answer:
[tex]1 Pa\times mm^{2} =10^{-6}Pa\times m^{2}[/tex]
Explanation:
Pascal(Pa) : It is the SI unit of pressure.It is equal to 1 Newton per meter square(Pa =[tex]N/m^{2}[/tex])
[tex]Pa\times mm^{2}[/tex] is the Unit of Force(Newton=N)
Calculation,
It is required to convert [tex]mm^{2}[/tex] to [tex]m^{2}[/tex] only, Pa is same in both so no need to alter Pa.
1 m = 1000 mm (see the image)
And,
1 mm = 0.001 m
[tex]1 mm^{2} = 0.001\times 0.001 m^{2}[/tex] (Squaring both side)
[tex]1 mm^{2} = 0.000001 m^{2}[/tex]
[tex]1 mm^{2} = 10^{-6}m^{2}[/tex]
So,
[tex]1 Pa\times mm^{2} =10^{-6}Pa\times m^{2}[/tex]
NEED THE ANSWER !!! NOW i have like an hour
Which chemical reaction model is flawed?
A.
4 C2 + S8 → 4 CS2
B.
2 Fe + 3 Cl2 → 2 FeCl3
C.
2 Na + Cl2 → 2 NaCl
D.
P4O10 + 6 H2O → 4 H3PO4
Part 2
Which best explains the correct answer to Part 1?
A.
The products side of the equation should include water.
B.
The model shows an unbalanced number of carbon atoms.
C.
The coefficients on the reactants and products sides of the equation do not match.
D.
The same elements are on both the reactants and products sides of the equation.
Answer No 1:
The chemical model that is flawed is:
4 C2 + S8 → 4 CS2
In this reaction, there are more number of carbon atoms in the reactants but lesser number of cabon atoms in the products. For a reaction to be balanced, there should be the same number of atoms in the reactants and products. Hence, option A does not represent a balanced equation.
Answer No 2:
The correct option is B) The model shows an unbalanced number of carbon atoms.
Consider the equation:
4 C2 + S8 → 4 CS2
In the reactants side of the equation, there are 8 atoms of carbon. In the products side there are only four carbon atoms. This shows that this equation in not balanced because of the carbon atoms.
The number of sulfur atoms remains same before the reaction and after the reaction. There are eight sulfur atoms in the reactants as well as products.
How does soil convert the organic matter back to CO2?
Erinn
Answer & explanation:
Soil carbon transformations have two phases: The first one is the atmospheric carbon dioxide (CO₂) fixation phase, which is performed by photosynthetic organisms, in which there is synthesis of organic compounds.
These compounds return to the soil and are used by organisms that regenerate CO₂ during respiratory oxidation reactions, using energy for their maintenance and growth.
After this, the regeneration phase begins, which corresponds to the stages of decomposition of organic molecules by the action of the soil microbiota.
Thus, soil microbiota (mainly fungi and bacteria) use waste components as a substrate for energy and also as a carbon resource in the synthesis of new cells. Energy is supplied to microbial cells by the oxidation of organic compounds. The end product is CO₂, which is released into the atmosphere.
Determine the equilibrium concentration when 1.00 mole of I2 and 1.00 mole of H2 are put into a 5 liter container. At the reaction temperature, the Keq is 64.0
H2 (g) + I2 (g) 2HI (g)
Answer:
The equilibrium concentration are :
[tex]{H_{2}}[/tex] = 0.04 M
[tex]{I_{2}}[/tex] = 0.04 M
[tex]{HI}[/tex] = 0.16 M
Explanation:
[tex]{H_{2}} + {I_{2}} \rightleftharpoons 2 HI[/tex]
it means 1 mole of iodine and hydrogen produce 2 mole of HI
Concentration(C) : Moles per unit volume.It is expressed in Molarity
(M=mol/L )
[tex]concentration = \frac{moles}{volume}[/tex]
Initial moles :
[tex]{H_{2}}[/tex] = 1.00
So, [tex]C = \frac{1}{V}[/tex]
[tex]{I_{2}}[/tex] = 1.00
[tex]C = \frac{1}{V}[/tex]
[tex]{HI}[/tex] = 0
[tex]C = \frac{0}{V}[/tex]
let during the reaction x moles of both [tex]{H_{2}}[/tex] and [tex]{I_{2}}[/tex] get dissociated , then
At equilibrium ,
[tex]{H_{2}}[/tex] = 1.00 - x
[tex]C = \frac{1-x}{V}[/tex]
For iodine
[tex]{I_{2}}[/tex] = 1.00 - x
[tex]C = \frac{1-x}{V}[/tex]
1.00 - x mole of hydrogen will produce 2x of HI
[tex]{HI}[/tex] = 2x
[tex]C = \frac{2x}{V}[/tex]
[tex]K_{eq} = \frac{[products]^{coefficient}}{[reactants]^{coefficient}}[/tex]
On solving for x , (look at the image)
[tex]{H_{2}}[/tex] = 0.04 M
[tex]{I_{2}}[/tex] = 0.04 M
[tex]{HI}[/tex] = 0.16 M
Final answer:
To find the equilibrium concentrations of H₂, I₂, and HI in the reaction H₂(g) + I₂(g) → 2HI(g), we must solve a quadratic equation using the given Keq of 64.0 and the initial concentrations calculated from the amounts and volume of the container.
Explanation:
Equilibrium Concentrations Calculation
To determine the equilibrium concentration of species in a reaction mixture, we can use the equilibrium constant (Keq) and the initial concentrations. For the reaction H₂(g) + I₂(g) → 2HI(g), we're given that the initial amounts are 1.00 mole of H₂ and 1.00 mole of I₂ placed into a 5-liter container. The equilibrium constant (Keq) at the reaction temperature is 64.0.
First, we calculate the initial concentrations:
Initial concentration of H₂ = (1.00 mole) / (5.00 L) = 0.20 M
Initial concentration of I₂ = (1.00 mole) / (5.00 L) = 0.20 M
Initially, the concentration of HI is zero since the reaction hasn't started.
At equilibrium, we'll have changed concentrations as follows, assuming x moles of H₂ react:
[H₂] = [I₂] = 0.20 M - x
[HI] = 0 + 2x
From the equilibrium expression,
Keq = [HI]^2 / ([H₂][I₂])
64.0 = (2x)^2 / ((0.20 - x)(0.20 - x))
We solve this quadratic equation for x to find the equilibrium concentrations.
After finding the value of x, we can determine the concentrations at equilibrium:
[H₂] = [I₂] = 0.20 M - x
[HI] = 2x
The following questions pertain to a system contains 122 g CO(g) in a 0.400 L container at -71.2 degrees C.
a.Calculate the pressure exerted by the CO(g) in this system using the ideal gas equation.
b. The actual pressure exerted by the carbon monoxide gas is this system was found to be 145 atm. Explain why the actual pressure is less than what would be expected?
Answer:
a. P = 182 atm
Explanation:
Data Given:
amount of CO = 122g
Volume of CO = .400 L
Temperature of CO = -71.2°C
Convert the temperature to Kelvin
T = °C + 273
T = -71.2 + 273
T = 201.8 K
a. Calculate the pressure exerted by the CO(g) in this system using the ideal gas equation (P) = ?
Solution:
To calculate Pressure by using ideal gas formula
PV = nRT
Rearrange the equation for Pressure
P = nRT / V . . . . . . . . . (1)
where
P = pressure
V = Volume
T= Temperature
n = Number of moles
R = ideal gas constant = 0.08206 L.atm / mol. K
For this we have to know the mole of the gas and the following formula will be used
no. of moles = mass in grams / molar mass . . . . . . (2)
Molar mass of CO = 12 + 16 = 28 g/mol
Put values in equation 2
no. of moles = 122 g / 28 g/mol
no. of moles = 4.4 mol
Now put the value in formula (1) to calculate Pressure for CO
P = 4.4 x 201.8 K x 0.08206 (L.atm/mol. K) / 0.400 L
P = 182 atm
So the pressure will be 182 atm
__________
b. Data Given:
Actual pressure exerted by CO = 145 atm
expected pressure exerted by CO = 182 atm
why the actual pressure is less than what would be expected = ?
Explanation:
This is because of the deviation from ideal behavior of real gases.
The real gases approach to ideal behavior under very high temperature and very low pressure.
But CO deviate from ideal behavior to give expected value for pressure, because it behave at high pressure and low temperature.
This non-ideal behavior is due to two postulate of ideal behavior
gas molecules have negligible volumeGas molecules have negligible inter-molecular interactionbut these postulates not obeyed under real condition. so we calculated the pressure using ideal condition values for gas and obtained the expected value for pressure but the actual pressure value was detected under normal condition.
Would it be C???...idk
HELP
Answer:
C. Butanal , is the aldehyde
Explanation:
A . It is carboxylic acid : ---COOH group
B. It is Ester : ----COOR group , Here R = CH3
C. It is Aldehyde : -----CHO group
D. It is ketone : ----C=O group
See image :
How many grams of zinc are needed to produce 25.0 g ZnCl2
Final answer:
The grams of zinc needed are 11.98 g.
Explanation:
To determine how many grams of zinc are needed to produce 25.0 g of [tex]ZnCl2[/tex], we first need to calculate the molar mass of [tex]ZnCl2[/tex] which is (65.39 g/mol for Zn + 2 × 35.45 g/mol for Cl) = 136.29 g/mol.
Next, using stoichiometry, we use the molar mass of [tex]ZnCl2[/tex] to find out how many moles 25.0 g of [tex]ZnCl2[/tex] is, and subsequently, using the molar mass of Zn (65.39 g/mol), we find out the mass of Zn that would produce that number of moles of [tex]ZnCl2[/tex]
The calculation goes as follows:
Calculate moles of [tex]ZnCl2[/tex]: 25.0 g ZnCl2 ÷ 136.29 g/mol = 0.1833 mol [tex]ZnCl2[/tex]
Since the stoichiometry between Zn and ZnCl2 is 1:1, we have the same number of moles of Zn.
Calculate mass of Zn needed: 0.1833 mol Zn × 65.39 g/mol = 11.98 g Zn
Therefore, 11.98 g of zinc are needed to produce 25.0 g of [tex]ZnCl2[/tex]
Put these different types of radiation in order from MOST to LEAST penetrating.
A) Alpha > Beta > Gamma
B) Gamma > Alpha > Beta
C) Gamma > Beta > Alpha
D) Beta > Gamma > Alpha
Answer:
C. Gamma > beta > alpha
Explanation:
Alpha rays : These are positively charged and have mass 4u. These contain high energy Helium nucleus with 2 proton and 2 neutron.
These are heavier and maximum charged than beta and gamma particles.They have low velocity,least penetration power (can't travel more than 10-18 cm).
Beta rays : They are negatively charged and have negligible mass.
On emmission of beta particle, neutron is divided into proton and electron. They have less mass and very high velocity, so their penetrating power is more than alpha particles.
Gamma rays: These are parts of electromagnetic spectrum and travel with the speed of light (maximum velocity).Gamma rays do not have mass have maximum penetrating power.
in which group does each element have a total of four electrons in the outermost principal energy level
Answer:
Group 14
Explanation:
The elements of the Periodic Table are arranged into 18 Groups.
Among the "main group elements" — those in Groups 1, 2 and 13 to 18 — the number of valence electrons — the number of electrons in the outermost energy level — corresponds to the last digit of the Group number.
Thus, Group 14 contains the elements with four valence electrons — C, Si, Ge, Sn, Pb, and Fl.
If Ca is the new standard of atomic mass and is assigned a value of 50.00 amu, what is the molar mass of Aluminium Acetate using this standard?
How does one solve this?
Answer:
848.1 g/mol
Explanation:
Data given:
Standard of atomic mass of Ca = 50 amu
molar mass of Aluminium Acetate = ?
Solution:
Relative atomic mass represented by Ar. It is ratio of actual mass with respect to the 1/12th mass of C-12 but here Ca-50 is standard.
Formula of Aluminium Acetate = Al(CH₃COO)₃
In order to calculate Ar
first we will calculate 1/50 of Ca
As we know
mass of 1/12 of C-12 = 1.993 x 10⁻²⁶/12 = 1.661 x 10⁻²⁷ Kg
So, for Ca-50
mass of 1/50 of Ca-50 = 1.993 x 10⁻²⁶/50 = 3.986 x 10⁻²⁸ Kg
Now
Relative Atomic mass for element X = rest mass of "X"/ 3.986 x 10⁻²⁸ Kg . . . . . . (1)
First we have to know the relative atomic masses of Aluminium, carbon, hydrogen, oxygen atoms involve in Aluminium Acetate formula with respect to new standard Ca-50
By using equation-1 we can calculate Ar for which we have reported rest masses of atoms as below
Rest mass of Aluminium = 4.48 x 10⁻²⁶ Kg
Rest mass of carbon = 1.993 x 10⁻²⁶ Kg
Rest mass of hydrogen = 1.608 x 10⁻²⁷ Kg
Rest mass of oxygen = 2.657x10⁻²⁶ Kg
Now put values in equation 1 for each atom
Ar for Aluminium= 4.48 x 10⁻²⁶Kg / 3.986 x 10⁻²⁸ KgAr for Aluminium = 112.5 amu
Ar for Carbon= 1.993 x 10⁻²⁶ Kg / 3.986 x 10⁻²⁸ Kg
Ar for Carbon= 50 amu
Ar for Hydrogen = 1.608 x 10⁻²⁷ Kg / 3.986 x 10⁻²⁸ Kg
Ar for hydrogen = 4 amu
Ar for Oxygen = 2.657x10⁻²⁶ Kg / 3.986 x 10⁻²⁸ Kg
Ar for Oxygen = 66.6 amu
Now find the molar mass of Al(CH₃COO)₃
molar mass of Aluminium Acetate = Al(CH₃COO)₃
Al(CH₃COO)₃ = 112.5 + 3 (50 + 3(4) + 50 + 66.6 +66.6)
Al(CH₃COO)₃ = 112.5 + 3 (50 + 12 + 50 + 66.6 +66.6)
Al(CH₃COO)₃ = 112.5 + 3 (245.2)
Al(CH₃COO)₃ = 112.5 + 735.6
Al(CH₃COO)₃ = 848.1 g/mol
molar mass of Aluminium Acetate = 848.1 g/mol
The enthalpies of formation of the compounds in the combustion of methane, , are CH4 (g): Hf = –74.6 kJ/mol; CO2 (g): Hf = –393.5 kJ/mol; and H2 O(g): Hf = –241.82 kJ/mol. How much heat is released by the combustion of 2 mol of methane? Use . 80.3 kJ 802.5 kJ 1,605.1 kJ 6,420.3 kJ
Answer:
ΔH°c = - 1605.1 KJ
Explanation:
CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)∴ ΔHf CH4(g) = - 74.6 KJ/mol
∴ ΔHf CO2(g) = - 393.5bKJ/mol
∴ ΔHfH2O(g) = - 241.82 KJ/mol
standard enthalpy of combustion (ΔH°c):
⇒ ΔH°c = (2)(ΔHf H2O) + ΔHfCO2 - ΔHfCH4
⇒ ΔH°c = (2)(- 241.82) + ( - 393.5 ) - ( - 74.6 )
⇒ ΔH°c = - 802.54 KJ/mol
⇒ ΔH°c = ( - 802.54 KJ/mol )( 2 mol CH4 )
⇒ ΔH°c = - 1605.08 KJ
Answer:
C on Edge
Explanation:
NEED HELP ASAP!!! What is the density of each of the following gases at STP? Show your work.
A. C3H3
B. Ne
C. NO2
Answer:
A. 1.63g/dm^3 (3 s.f.)
B. 0.833g/dm^3 (3 s.f.)
C. 1.92g/dm^3 (3 s.f.)
Explanation:
Please see attached picture for full solution.
The density of gases at STP can be calculated using the molar mass and molar volume. C3H3 has a density of 1.74 g/L, Ne has a density of 0.90 g/L, and NO2 has a density of 2.06 g/L at STP.
Explanation:A. C3H3 (Propyne):
To calculate the density, we need to know the molar mass of the gas. The molar mass of C3H3 is 39.05 g/mol. At STP (Standard Temperature and Pressure), the molar volume of a gas is 22.4 L/mol. Therefore, the density of C3H3 at STP is:
Density = molar mass / molar volume
Density = 39.05 g/mol / 22.4 L/mol
Density = 1.74 g/L
B. Ne (Neon):
The molar mass of Neon is 20.18 g/mol. Using the same formula as above, we can calculate the density of Neon at STP:
Density = 20.18 g/mol / 22.4 L/mol
Density = 0.90 g/L
C. NO2 (Nitrogen Dioxide):
The molar mass of NO2 is 46.01 g/mol. Again, using the formula:
Density = 46.01 g/mol / 22.4 L/mol
Density = 2.06 g/L
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The accepted value for the molar volume of a gas is
22.4 liters. In a laboratory experiment, a student
determines the value to be 24.8 liters. What is the
percent error of the student's measurement?
A) 0.120%
B) 0.107%
C) 10.7%
D) 12.0%
Answer:
C)10.7%
Explanation:
24.8-22.4=2.4
22.4→100%
2.4→X%
X=2.4×100/22.4=10.7%
The percent error of the student's measurement, using the correct calculations, is approximately 10.7%.
Explanation:The percent error is calculated using the formula: percent error = |(experimental value - accepted value)| / accepted value x 100%.
In this case, the accepted value of the molar volume of a gas is 22.4 liters (accepted value), and the student determined the value to be 24.8 liters (experimental value).
Thus, the percent error would be |(24.8 - 22.4)| / 22.4 x 100%, which results in approximately 10.7%. Therefore, the correct answer would be C) 10.7%.
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The neutron was not discovered until 1932, more than thre
of the electron. Which of the following best explains why e
deduce the existence of the neutron?
ed until 1932, more than three decades aller
ng best explains why earlier scientists were unable to
A
The heavy mass of the nucleus meant that it was difficult to quantity
B
The neutron is a tiny, massless particle that is difficult to observe.
C
Atoms contain varying numbers of neutrons, therefore an average had to be
calculated.
D
The neutron has a neutral charge, which made it impossible to discover using
previous experiments with positive and negative charges.
Answer:
Correct option is D) The neutron has a neutral charge, which made it impossible to discover using previous experiments with positive and negative charges.
Explanation:
The protons are the positively charged particles of an atom. The electrons are the negatively charged particles of an atom. As both the particles carry some kind of charge i.e either positive or negative, hence their discovery was easier.
The neutrons are the part of an atom which are neutral and do not carry any charge. Hence, their discovery took a more longer time as compared to the discovery of electrons and protons.
Using the reaction given above, how many moles of sodium bicarbonate are needed to produce 24 L of
sodium citrate (NazC,H,O,)? (Density of sodium citrate is 1.7 g/mL)
Answer:
474.3 mol
Explanation:
The reaction between sodium bicarbonate and citric acid may be represented by:
[tex]3 NaHCO_3 (aq) + H_3C_6H_5O_7 (aq)\rightarrow Na_3C_6H_5O_7 (aq) + 3 H_2O (l) + 3 CO_2 (g)[/tex]
According to the equation, 3 moles of sodium bicarbonate are required to produce 1 mole of sodium citrate. Let's find the number of moles of sodium citrate as our next step. We'll need its mass and its molar mass.
To find the mass of sodium citrate, we may multiply the density by the volume of the product:
[tex]m_{product} = 1.7 g/ml\cdot \frac{1000 mL}{1 L}\cdot 24 L = 40800 g[/tex]
Dividing this by the molar mass of sodium citrate will produce the number of moles:
[tex]n_{product} = \frac{40800 g}{258.06 g/mol} = 158.1 mol[/tex]
From the stoichiometry of the given equation, we already know that the number of moles of sodium bicarbonate can be found by multiplying the moles of sodium citrate by 3:
[tex]n_{NaHCO_3} = 3\cdot 158.1 mol = 474.3 mol[/tex]
in a reaction that occurs in a solution, the volume will not change. What happens to the concentration of the reactants? What happens to the reaction rate as the reaction continues?
Answer:
Concentration of the reactants decreases;
Rate of a reaction decreases
Explanation:
Since volume is held constant in a solution, the concentration of the reactants will decrease.
Simply speaking, concentration is the ratio between moles and volume. Volume is constant here. Over time, the number of moles of the reactants will decrease, as they react to produce products and they are disappearing. Since moles are directly proportional to concentration, this implies that concentration will also decrease, while the concentration of the products will increase, as they're formed.
The rate of a reaction decreases as the reaction continues, as we have lower and lower amounts of the reactants remaining in the solution as time progresses. Therefore, the probability of a successful collision leading to products decreases.
Um...idk...would it be D?
Answer:
yes it would be D. because passive prostheses are lightweight and don't have active movement
Explanation:
PLEASE HELP!!
Which of the following is true about the mass of an object?
It is equal to its weight.
It is proportional to its weight.
It is always more than its weight
It changes at different locations.
Answer:
It is proportional to its weight.
Explanation:
Answer:
The correct answer is "It is proportional to its weight."
Explanation:
Mass is the amount of matter that a body contains. Weight is the action exerted by the force of gravity on the body.
The mass of an object will always be the same, regardless of where it is located, because the amount of matter does not vary. Instead, the weight of the object will vary according to the force of gravity acting on it.
The mass is measured in kilograms (kg) and the weight is measured in newtons (N).
The weight is equal to the product of the object's mass and the value of the local gravitational acceleration:
P = m * g
It can be seen that the weight is proportional to the mass of the object.
The symbol Ca-40 denotes that
A. a calcium atom contains 40 protons
B. a calcium atom contains 40 electrons
C. a calcium atom contains 40 neutrons
D. a calcium atom has a mass number of 40
The Ca-40 notation indicates that this calcium isotope has a mass number of 40, which is made up of 20 protons and 20 neutrons.
Explanation:The symbol Ca-40 represents a calcium isotope and indicates the mass number of this particular atom. The mass number is the sum of the number of protons and neutrons in an atom's nucleus. Calcium's atomic number, which is the number of protons, is 20. To find the number of neutrons, we subtract the atomic number from the mass number. Hence, the number of neutrons in Ca-40 is 40 - 20 = 20 neutrons. From the provided options, the correct statement is D. A calcium atom has a mass number of 40.
The symbol Ca-40 denotes a calcium atom which has a mass number of 40. The mass number is the sum of the protons and the neutrons in an atom. To find the number of neutrons, we subtract the number of protons from the mass number. Therefore, the correct answer is D. a calcium atom has a mass number of 40.
They escape of dissolved oxygen from the ocean into the atmosphere allowed the ozone layer to form true or false
Answer:
True
Explanation:
The formation of ozone molecules from oxygen molecules is quite a complex radical mechanism, besides, it usually involves the radicals of other gases present in the atmosphere.
Sunlight promotes the formation of these radicals and this is true that in the atmosphere, oxygen is converted into ozone by the following net reaction:
[tex]3 O_2 (g) \rightarrow 2 O_3 (g)[/tex]
The oxygen molecules present in the ocean may have enough kinetic energy to escape the surface of the ocean and reach the atmosphere. When sunlight is used, this conversion from oxygen to ozone becomes possible.
Pb(CH3COO)2 + H2S → PbS + CH3COOH (Need to balance equation)
How many grams of PbS is produced when 5.00g of H2S is reacted with an excess (unlimited) supply of Pb(CH3COO)2?
Answer:
Mass of PbS = 9.26 g
Explanation:
Data Given :
mass of H₂S = 5.00 g
mass of PbS = ?
Reaction Given:
Pb(CH₃COO)₂ + H₂S ----→ PbS + CH₃COOH
Solution:
Balance the equation:
Pb(CH₃COO)₂ + H₂S ----→ PbS + 2CH₃COOH
Now Look for the number of moles of H₂S and PbS meta
Pb(CH₃COO)₂ + H₂S ----→ PbS + 2CH₃COOH
1 mol 1 mol
So,
1 mole of H₂S combine with excess (unlimited) supply of Pb(CH₃COO)₂ and produce 1 moles of PbS
Now Convert moles to mass for which we have to molar masses of H₂S and PbS
Molar mass of H₂S = 2 + 32 = 43 g/mol
Molar mass of PbS = 31 + 32 = 63 g/mol
Pb(CH₃COO)₂ + H₂S -------→ PbS + 2CH₃COOH
1 mol (34 g/mol) 1 mol (63 g/mol)
34 g 63 g
So,
34 g of H₂S produces 63 grams of PbS.
Now
What mass of silver is produced from 5 g of H₂S
Apply unity formula
34 g of H₂S ≅ 63 g of PbS
5 g of H₂S ≅ X g of PbS
By doing cross multiplication
Mass of PbS = 63 g x 5 g / 34 g
Mass of PbS = 9.26 g
To balance the given equation, add a coefficient of 2 in front of CH3COOH. 0.147 mol of PbS is produced, which is equal to 35.19 g of PbS.
Explanation:To balance the given equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation. Let's start by counting the number of atoms for each element in the given equation:
Pb: 1 on both sidesH: 6 on both sidesC: 4 on both sidesO: 2 on the reactant side and 4 on the product sideS: 1 on the reactant side and 1 on the product sideFrom the above counts, we can see that the number of oxygen atoms is not balanced. We can balance the equation by adding a coefficient of 2 in front of CH3COOH:
Pb(CH3COO)2 + H2S → PbS + 2CH3COOH
Now, the equation is balanced, and we can calculate the number of grams of PbS produced. From the balanced equation, we can see that 1 mole of PbS is produced for every 1 mole of H2S reacted. The molar mass of H2S is 34.08 g/mol, so 5.00 g of H2S is equivalent to 5.00/34.08 = 0.147 mol. Therefore, 0.147 mol of PbS is produced, which is equal to 0.147 x 239.36 = 35.19 g of PbS.
how many moles are in 4.99x1032 molecules of H2o
Answer:
n≈8,29×10⁸ moles
Explanation:
Nᴀ=6.02×10²³ (constant)
n=N/Nᴀ=
[tex] = \frac{ {4.99 \times 10}^{32} }{6.02 \times 10 ^{23} } = 828903654 [/tex]
≈8,29×10⁸ moles