Answers are:
2. It pushes on all objects that are on Earth’s surface.
3. It can be measured in atmospheres or kilopascals.
Barometric pressure (atmospheric pressure), is the pressure within the atmosphere of Earth
Atmospheric pressure decreases with increasing height, because there are fewer air molecules above a given object.
Barometer is an instrument used in meteorology to measure atmospheric pressure.
Atmospheric pressure (atm) is the force per unit area by the weight of air above that point.
Kilopascal (kPa) is a metric system pressure unit and equals to 1000 force of newton per square meter.
Atmospheric pressure results from molecular collisions of atmospheric gases.
Answer:
2 & 3
Explanation:
the phase change that is reverse of evaporation is
Condensation is the reverse change of evaporation.
The phase that is the reverse of evaporation is Condensation.
It is the process by which gas is cooled to any temperature above it freezing point to make it into liquid form.
The properties of a given substance are governed by various forces or interactions. Consider the following 4 forces or interactions: covalent bonding dispersion forces hydrogen bonding dipole-dipole interactions Which of the following correctly lists these four types of interactions/forces according to increasing strength (weakest to strongest)? hydrogen; dipole; covalent; dispersion
Answer:
weakest to strongest
dispersion forces dipole-dipole interactionshydrogen bonding covalent bondingExplanation:
Covalent bonding is an intramolecular interactions that hold the atoms together. Dispersion forces, hydrogen bonding and dipole-dipole interactions are intermolecular interactions . Intramolecular interactions are stronger than intermolecular interactions .
Dipole-dipole interactions occur when the partially positively charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule. They are relative strong.
Hydrogen bonding is a special kind of dipole-dipole interaction that occurs specifically between a hydrogen atom bonded to either an oxygen, nitrogen, or fluorine atom. It is the strongest dipole-dipole interaction.
Dispersion forces exist between all types of molecules, whether ionic or covalent (polar or nonpolar). They are the weakest of the intermolecular forces.
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.
3H2+N2-->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 (a) : [tex]3H_2(g)+N_2(g)\rightarrow 2NH_3(g)[/tex]
Part (b) : Theoretical yield of [tex]NH_3[/tex] = 440.96 g
Part (c) : Percentage yield of ammonia is 90.03 %
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
Part (a) :The balanced chemical reaction will be:
[tex]3H_2(g)+N_2(g)\rightarrow 2NH_3(g)[/tex]
Part (b) :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 balanced equation:
1 mole of [tex]N_2[/tex] gas produces 2 moles of [tex]NH_3[/tex]
16.96 moles of [tex]N_2[/tex] gas produces [tex]\frac{2}{1}\times 16.96=33.92[/tex] moles of [tex]NH_3[/tex]
Now we have to calculate the mass of [tex]NH_3[/tex]
[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
Part (c) : Percentage 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 %
As a cooking method, braising is valued for its A. ability to retain flavor. B. quickness and convenience. C. ability to create delicate flavors. D. simplicity and versatility.
Answer: Option (A) is the correct answer.
Explanation:
Braising means first of all fry a dish slightly and then cook it slowly in a closed vessel or dish. The vessel is close so that the liquid present inside it does not evaporates.
Also, Braising is done to mix the flavors of different liquids or spices appropriately.
Thus, we can conclude that as a cooking method, braising is valued for its ability to retain flavor.
Answer:
The correct answer is D.
Explanation:
This method of cooking is economical because it allows the use of common cuts, it is efficient because it allows to prepare the food in a single pot. The preparation is simple as it does not require an elaborate preparation. The meat is cooked in a pot, seasoned from the beginning, and there is no need to intervene in the process.
Have a nice day!
Which is true about each element in a period or horizontal row of the periodic table?
A.
Each element has one more outer shell than the element before it.
B.
Each element has one more outer electron than the element before it.
C.
Each element has one more isotope than the element before it.
D.
Each element bonds with the element before it.
The answer is B as going from left to right on the periodic table elements increase by 1 in valence electrons
Valence electrons : The electrons on the outermost shell
Convert 2.5 grams of water to molecules of water.
A mole of water is 18 g. This is the molar mass of H2O (16 for O plus 2 for 2 H).
So In 2.5 g you have 2.5/18 Moles of water. 2.5/18 * Avogadro constant gives you the number of molecules. This should be 8.37 x 10^22 molecules. Good luck!!
A chemical bond formed between two atoms share electrons is called a(n) ____.
a. 8 Valence Electrons
b. No Valence Electrons
c. 7 Valence Electrons
d. 17 Valence Electrons
The correct answer is that a chemical bond formed when two atoms share electrons is called a Covalent Bond, though this option is not provided in the question. This type of bond is exemplified by the bonding in a hydrogen molecule (H2).
Explanation:The question seems to have a typographical error. It appears to be asking about a certain type of chemical bond, specifically one formed when two atoms share electrons. However, none of the answer choices appear to correctly describe this type of bond. The appropriate response for a chemical bond that involves sharing of electrons would be a Covalent Bond. A typical example of this would be the bonding between two Hydrogen atoms in a H2 molecule, where they share their singular electron to fulfil their respective octet.
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For the unbalanced equation, what is the coefficient for C5H10? ? C5H10 (l) +? O2 (g) →? CO2 (g) +? H2O (g) A. 2 B. 4 C. 10 D. 6 E. 1
1C5H10 + 15/2O2 => 5CO2 + 5H2O
Explanation:
Balanced equation is defined as the equation which contains same number of atoms on both reactant and product side.
For example, [tex]C_{5}H_{10}(l) + O_{2} \rightarrow CO_{2}(g) + H_{2}O(g)[/tex]
Number of atoms on reactant side are as follows.
C = 5H = 10O = 2Number of atoms on product side are as follows.
C = 1H = 2O = 3So, to balance this equation we will multiply [tex]CO_{2}[/tex] on product side by 5 and also multiply [tex]H_{2}O[/tex] by 5. On the reactant side, we multiply [tex]O_{2}[/tex] by [tex]\frac{15}{2}[/tex]. Therefore, the balanced equation is as follows.
[tex]C_{5}H_{10}(l) + \frac{15}{2}O_{2} \rightarrow 5CO_{2}(g) + 5H_{2}O(g)[/tex]
Thus, we can conclude that for the given unbalanced equation the coefficient for [tex]C_5H_10[/tex] is 1.
1. A student represented a water molecule using beads and straws. She connected two black beads and one white bead in a certain manner using straws. Which of the following explains the type of scientific model created by the student?
A. A simulation because it helps visualize the shape of the molecule.
B. A 3-dimensional model because it helps visualize the shape of the molecule.
C. A simulation because it helps understand the movement of atoms in the molecule.
D. A 3-dimensional model because it helps understand the movement of atoms in the molecule.
Answer: Option (b) is the correct answer.
Explanation:
When the student is using beads then he is representing atoms and the straws represent the bond between the atoms.
Therefore, when a model is represented by the given manner then it helps in identifying the geometry or shape of the object. This is because it shows how atoms are arranged in space along with their angle.
Therefore, we can conclude that out of the given options the type of scientific model created by the student is a 3-dimensional model because it helps visualize the shape of the molecule.
The type of scientific model created by the student has been the 3-D model for the visualization of shape. Thus, option B is correct.
The water molecule has been the simplest compound that has been consisted of the two hydrogen atoms bonded with an oxygen atom.
The presence of loan pairs to the oxygen atom has been responsible for the distortion in the linear shape, and the molecule has been present in the inverted geometry.
The model prepared by the student has black beads as the representation of the hydrogen atoms, while white beads as the representation of the oxygen atom. The straws have been the representation of the bonds in the structure.
The model prepared has been capable of demonstrating the arrangement of the elements in the 3-D plane and has been able to elucidate the structure of the molecule. Thus, option B is correct.
For more information about the scientific model, refer to the link:
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Which element has the strongest intermolecular forces at room temperature? A) I (s) B) F (g) C) Br (l) D) Cl (l)
A) I or Iodine
Iodine is solid which will be in a more fixed position and held closer together making it harder to break apart. It has more electrons and therefore more van der waals forces acting on it, which require more energy to break apart.
answer: a. I
explanation: iodine is a solid meaning the particles are closer together and holds a more fixed position, making it harder to break apart unlike a liquid or gas where the particles are more spread apart
A hexagon can be used to represent the structure of cyclohexane. What does each side of the hexagon represent?
Answer:
Single bond between two carbon atoms.
Explanation:
Let us look at the structure of a hexagon for representation of cyclohexane.
Cyclohexane has six carbons and thus we can place each carbon at the vertices of the hexagon. Now the bond joining each adjacent carbon atoms will be shown by the each side of the hexagon.
The hydrogen atoms are not shown in the structure.
Answer:
Single bond between two carbon atoms.
Explanation:
Given: CH4 + 2O2 → CO2 + 2H2O In the chemical reaction, if 10 moles of H2O are produced, ____ moles of CO2 are also produced.
Answer: 5 moles of [tex]CO_2[/tex] will be produced when 10 moles of [tex]H_2O[/tex] are produced.
Explanation:
[tex]CH_4+2O_2\rightarrow CO_2+2H_2O[/tex]
Multiplying the chemical equation with 5.
[tex]5CH_4+10O_2\rightarrow 5CO_2+10H_2O[/tex]
In the given reaction ,if 10 moles of water are produced then 5 moles of Carbon-dioxide produced.
Answer:
5
Explanation:
For each pair below, select the sample that contains the largest number of moles .
If you need the answer to this problem you need to post more information about the problem.
Answer:
Pair A: B
Pair B: A
Pair C: B
What is the main reason why some developing countries fear the increase the free trade policies around the world?
It threatens local industries. This is because local industries are smaller in scale than the industries that have international reach. The local industries cannot compete with the international industries because they cannot keep their prices as competitive because they lack economies of scale.
Circle three objects. Describe two forms of energy each object has. Force and Energy page 118.
Here is the answer!!! Just fill in the blanks.
The ratio between the force of sliding friction and the normal force of an object is called _____.
A.rolling friction
B.the drag
C.the coefficient of friction
D.the starting friction
Answer: The correct answer is C.
Explanation: Frictional force is the contact force which resists the motion of one surface on another.
Mathematically,
[tex]f=\mu N[/tex]
where,
f = frictional force
[tex]\mu[/tex] = Coefficient of friction
N = normal force acting on a body
We need to find the ratio of force of sliding friction ( which is a type of frictional force) and the normal force acting on an object. This will be equal to coefficient of friction.
[tex]\mu=\frac{f}{N}[/tex]
2AgNO3 (s) + MgCl2 (aq) --> 2AgCl (s) + Mg(NO3)2 (aq) The student starts with 50.0 grams of mgcl2 and an excess of AgNO3. If she makes 125.1g of AgCl, what is her percent yield?
The percent yield is 83.12%
calculation
percent yield = actual yield / theoretical yield x 100
actual yield =125.1 g
Theoretical yield is calculated as below
Step 1: find the moles of MgCl₂
moles = mass÷ molar mass
from periodic table the molar mass of mgCl₂ =24.3 +(35.5 x2) =95.3 g/mol
moles = 50.0 g÷ 95.3 g/mol =0.525 moles
Step 2: use the mole ratio to determine the moles of AgCl
from given equation MgCl₂: AgCl is 1:2
therefore the moles of AgCl = 0.525 x2/1 =1.05 moles
Step 3: find the theoretical mass AgCl
mass = moles x molar mass
from periodic table the molar mass of Agcl = 107.87 +35.5 =143.37 g/mol
mass = 1.05 moles x 143.37 g/mol =150.5 grams
The percent yield is therefore = (125.1 g/150.5) x 100 = 83.12%
Substances a and b are both volatile liquids with p*a = 300 torr, p*b = 250 torr, and kb = 200 torr (concentration expressed in mole fraction). when xa = 0.9, bb = 2.22 mol kg−1, pa = 250 torr, and pb = 25 torr. calculate the activities and activity coefficients of a and
b. use the mole fraction, raoult's law basis system for a and the henry's law basis system (both mole fractions and molalities) for
b.
Use Raoult's Law and Henry's Law to calculate the activities and activity coefficients of substances a and b
Explanation:To calculate the activities and activity coefficients of substances a and b, we can use Raoult's Law for substance a and Henry's Law for substance b.
The activity of substance a can be calculated using:
a = a/*a
The activity of substance b in terms of mole fraction can be calculated using:
b = b/*b
The activity coefficient of substance a can be calculated using:
a = a/Xa
The activity coefficient of substance b can be calculated using:
b = b/Xb
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When an alkali metal is involved in a chemical reaction with a nonmetal, what charge will its atoms most likely form?
1-
2+
1+
2-
The charge that alkali metal form when they involve in a chemical reaction with non metals is 1+
Explanation
Metals react by losing electron to form a positively charged ion.
Alkali metal has 1 electron in outermost sub shell which is donated when they react with non metals to form ions with a charge of 1+.
For example sodium (Na) metal with [Ne] 3S¹ electron configuration donate the 1 electron in outermost subshell (3S) to form Na⁺ ion.
*explain your answer for brainliest
Aluminum reacts with chlorine gas to produce aluminum chloride according to the following equation.
Al + Cl2 → AlCl3
Which of the following fractions can be used for the mole ratio to determine the mass of Cl2 from a known mass of AlCl3?
two over one
three over two
one over two
two over three
Answer:
3 mol Cl₂/2 mol AlCl₃ (three over two)
Step-by-step explanation:
Start with the balanced equation"
2Al + 3Cl₂⟶ 2AlCl₃
The steps in the calculation are
mass of AlCl₃ ⟶ moles of AlCl₃⟶ moles of Cl₂ ⟶ mass of Cl₂
The critical step is the conversion of moles.
You multiply the moles of AlCl₃ by a conversion factor to get moles of Al:
Moles of AlCl₃ × conversion factor = moles of Al.
The conversion factor is the molar ratio, and it uses the coefficients of the formulas in the balanced equation.
It is either (2 mol AlCl₃/3 mol Cl₂) or (3 mol Cl₂/2 mol AlCl₃).
You choose the one that has the desired units of the answer in the numerator.
We choose the second option, because it has the correct units.
For example,
[tex]\text{0.2 mol AlCl}_{3} \times \frac{3\textbf{ mol Cl}_{2} }{ 2\text{ mol AlCl}_{3} } = 0.3\textbf{ mol Cl}_{2})[/tex]
Notice how the units "mol AlCl₃" cancel and the correct units appear in the answer.
If we had used the other conversion factor, we would have gotten the wrong units.
PLEASE SHOW WORK and include units on each number
Ammonia (NH3) reacts with oxygen (O2) to produce nitrogen monoxide (NO) and water (H2O). Write and balance the chemical equation. How many liters of NO are produced when 2.0 liters of oxygen reacts with ammonia? Show all work!
Answer is: 1.6 liters of NO are produced.
Balanced chemical reaction: 4NH₃ + 5O₂ → 4NO + 6H₂O.
V(O₂) = 2.0 L; volume of oxygen.
From balanced chemical reaction: n(O₂) : n(NO) = 5 : 4.
V(O₂) : V(NO) = n(O₂) : n(NO).
2.0 L : V(NO) = 5 : 4.
V(NO) = 2 L · 4 ÷ 5.
V(NO) = 1.6 L; volume of nitrogen (II) oxide.
Which metal is the best choice for recovering copper (reacting with copper) from the solution? Fe, Ag, Zn, or Al
Answer: The correct option is Aluminium.
Explanation: To recover copper from the solution, we require a metal which can easily displace copper from the solution.
The reactions in which metal displaces another metal in a chemical reaction are known as single displacement reactions. These reactions are studied using reactivity series.
[tex]A+BC\rightarrow AC+B[/tex]
A is more reactive than B.
The metal which lie above in the reactivity series will easily displace the metal which lies below in the reactivity series.
From the given options, Aluminium is the most reactive of all the metals and hence, it is the best choice for recovering copper from its solution.
Given a formula for oxygen: What is the total number of electrons shared between the atoms represented in this formula
Answer is: the total number of electrons shared between the atoms is four.
Molecule of oxygen is nonpolar because double linear bonds (O=O).
Oxygen (O) is an element with atomic number 8, it means it has eight protons and eight electrons, so atom has neutral charge. Oxygen is a nonmetal.
Electron configuration of oxygen atom: ₈O 1s² 2s² 2p⁴.
Oxygen atom has six valence electrons, so it is in 16 group of Periodic table of elements.
Two valence electrons from both oxygen atoms form double bond (O::O) at oxygen molecule.
Answer:
Formula for oxygen is [tex]O_{2}[/tex] and total number of electrons shared between the atoms are 4
Explanation:
Oxygen is a diatomic molecule. Hence two oxygen atoms combine to produce one oxygen molecule.
Now, number of valence electron in a oxygen atom is 6. So total number of valence electrons used to form oxygen molecule are 12.
To draw a Lewis structure for [tex]O_{2}[/tex], octet rule should be fulfilled by both oxygen atoms.
According to octet rule, an atom should have 8 electrons in its valence shell
Lewis structure for oxygen molecule has been attached below.
Here electrons shared by oxygen atoms are represented as vertical line. These are called bonding electrons.
Unshared electrons are represented by dot. These are called lone pairs.
Here one bond is formed by sharing two electrons.
As there are two bonds between two oxygen atoms therefore total number of shared electrons between oxygen atoms are 4.
Freezing and Boiling are endothermic processes. This means that these processes absorb energy from their surroundings in order to occur. Use this information and the data you collected in the Phase Change Gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.
Hi my dear friend,
Changes of state involve a solid melting, a liquid freezing, a liquid boiling or a gas condensing. When steam, which is gaseous water, condenses, heat is released. Likewise when liquid water freezes, heat is given off. In fact heat must be continually removed from the freezing water or the freezing process will stop.
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2,3,3,-3 Tetrafluoropropene (HFO-1234yf) is a popular hydrofluoroolefin with the molecular formula C4H2F4. What's the molar mass of this gas??!
pleaseeeeeeeeeeeee helppppppppppppppppppppp!!! FIRST ONE TO ANSWER WITH THE RIGHT ANSWER GETS BRAINLIEST!!
List three things found on the back of a pattern envelope.
Here you go !!!!! envelope, cutting and sewing instructions, tissue pattern pieces
__________ often cause overactive eye movement. A. Stimulants B. Depressants C. Barbiturates D. None of the above
Stimulants often cause overactive eye movement
Ans (A)
Stimulants are a class of psychoactive drugs that increase the brain activity. They work by acting on the central nervous system and increase the level of mental alertness and impart heightened cognitive functions. Stimulants like nicotine and cocaine cause overactive eye movement.
Answer:
( A). Stimulants is a correct answer.
Explanation:
Stimulants result in the overactive movement of eye.
Stimulants belong to the class psychoactive drugs which cause increase brain function.
Stimulants results in the change of the corneal curvature, and it increases the alertness and energy for a limited period of time.
Ritalin is a class of stimulants known as Methylphenidate and other stimulants like nicotine, cocaine result in overactive movement of the eye.
In this condition, people are not able to concentrate on multiple visual works at the same time.
A 0.3000-g sample of soda ash (which contains sodium carbonate) is dissolved in 50.00 mL of water. Titration with standard 0.1000 M HCl required 42.70 mL of the acid to neutralize the soda ash solution. What is the percent by mass of sodium carbonate in the soda ash sample? The molar mass of sodium carbonate is 105.99 g/mol. The equation for the reaction of sodium carbonate and hydrochloric acid is
How many grams of carbon monoxide are needed to react with an excess of iron (III) oxide to produce 198.5 grams of iron? Fe2O3(s) + 3CO(g) -----> 3CO2(g) + 2Fe(s) Show all work step by step please!
The grams of carbon monoxide that are needed to react is 148.68 grams
calculation
Step 1: find the moles of iron
moles =mass÷ molar mass
from periodic table the molar mass of Fe is 56 g/mol
= 198.5 g÷ 56 g/mol =3.54 moles
Step 2: use the mole ratio to determine the moles of carbon monoxide(Co)
that is from given equation Co : Fe is 3:2 therefore the moles of Co
= 3.54 x 3/2 = 5.31 moles
Step 3 : find mass of CO
mass = moles × molar mass
from periodic table the molar mass of Co = 12+16 = 28 g/mol
mass is therefore = 5.31 moles × 28 g/mol = 148.68 grams
During chemistry, Dan mixes two clear, colorless solution and mixing them produces a yellow precipitate in a clear, colorless final solution as shown by the chemical equation.
Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq)
What physical evidence indicates that there has been a chemical reaction?
Answer: Formation of precipitate indicates that there has been a chemical reaction.
Explanation:
Chemical reaction: It is defined as change in arrangement of the atoms so as to form a new substance.
Mixing of two clear solutions that is lead nitrate and potassium iodide gives out yellow solid precipitate of lead iodide with aqueous solution of potassium nitrate.
[tex]Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(s)+2KNO_3(aq)[/tex]
The physical evidence which indicates that chemical reaction has been taken place is formation of yellow solid precipitate of lead iodide ,([tex]PbI_2[/tex]).