Which of the following best describes hail?

A- Small ice pellets that may fall to the ground in a mixture of rain and snow in the form of a solid

B- A form of precipitation that occurs when liquid and frozen precipitation freezes in layers creating chunks

C- Water droplets that collide with others to form large drops as they leave the clouds and fall toward the ground

D- Solid precipitation that is formed in clouds as ice crystals that stick together in groups to form flakes and leave the clouds as flakes

Answer:

7.51

Explanation:

general gas law

the product of pressure and volume is divided by absolute temperature

Answer:

Explanation:

The algebraic sum of all the oxidation numbers of all atoms in a neutral compound is zero.

In order to know the formula of the negative Sulfur ion in pyrite, we must determine its oxidation state.

Let us make the make the oxidation number of sulfur = x

Therefore, FeS₂:

                      +2 +2x = 0

                      +2 = -2x

                       x = -1

The formula of the negative ion is S⁻

Answer:Carbon dioxide absorbs the most heat energy during SUBLIMATION. By definition, sublimation is the transition of a substance from the solid to the gas phase without passing through the intermediate liquid phase. Hope this answers your question.

Explanation:

Answer:

sublimation

Explanation:

Answer:

The suns mass affects the planets in the solar system because the grater the mas the stronger the gravitaional pull so the saster the planet orbits the sun.

Explanation:

Suns mass directly affected the position of planets in the solar system.

If the mass of the Sun is increased, the Sun would exert a stronger gravitational force on materials present around it. This change in mass of sun would disturb the orbits of all of the planets, pulling them closer to it.

So we can conclude that suns mass directly affected the position of planets in the solar system.

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Mg = 0

H =+1

Cl= -1

Mg= +2

Cl=-1

H= 0

Answer:

B,C,D,E

Explanation:

Edge

Answer:

a) 7.0.

b) Nickel sulfate hepta hydrate.

c) 280.83 g/mol.

d) 44.9%.

Explanation:

a) What is the formula of the hydrate?

The mass of the hydrated sample (NiSO₄.xH₂O) = 5.0 g,

The mass of the anhydrous salt (NiSO₄) = 2.755 g,

The mass of water = 5.0 g - 2.755 g = 2.245 g.

∴ no. of moles of water = mass/molar mass = (2.245 g)/(18.0 g/mol) = 0.1247 mol.

∴ no. of moles of anhydrous salt (NiSO₄) = mass/molar mass = (2.755 g)/(154.75 g/mol) = 0.0178 mol.

∴ water of crystallization in the sample (x) = no. of moles of water/no. of moles of anhydrous salt (NiSO₄) = (0.1247 mol)/(0.0178 mol) = 7.0.

b) What is the full chemical name for the hydrate?

The name of the salt (NiSO₄.7H₂O) is Nickel sulfate hepta hydrate.

c) What is the molar mass of the hydrate?

(NiSO₄.7H₂O)

The molar mass = molar mass of NiSO₄ + 7(molar mass of H₂O) = (154.75 g/mol) + 7(18.0 g/mol) = 280.83 g/mol.

d) What is the mass % of water in the hydrate?

The mass % of water = (mass of water)/(mass of hydrated sample) x 100 = (2.245 g)/(5.0 g) x 100 = 44.9%.

Answer: A

Explanation: Boiling point increases with the rise of electrons.

Answer:

Not sure what the answer is, but it's not A.

Explanation:

Submitted the problem and A was incorrect.

Answer:

Solution G has 100 times more hydroxide ions than Solution F.

Explanation:

∵ pH + pOH = 14.

∴ pOH = 14 - pH.

pOH = 14 - pH = 14 - 11 = 3.

∵ pOH = -log[OH⁻] = 3.

∴ [OH⁻] = 0.001 M.

pOH = 14 - pH = 14 - 13 = 1.

∵ pOH = -log[OH⁻] = 1.

∴ [OH⁻] = 0.1 M.

∴ [OH⁻] of solution G / [OH⁻] of solution F = (0.1)/(0.001) = 100.

So, Solution G has 100 times more hydroxide ions than Solution F.

Answer:

beryllium

Explanation:

isotopes are same elements

Answer:

beryllium-10

Explanation:

First let's remember what an isotope is

Isotopes are atoms of the same element, whose nucleus have a different amount of neutrons, and therefore, differ in mass number .

Since isotopes are atoms of the same element, the only option that corresponds to beryllium is the option beryllium-10

Answer:

1.) stability

2.) denser

3.) increase

4.) 1 millimeter

5.) regional

6.) more

7.) quartzite

8.) slate

Explanation:

Answer:

Stability , Denser,  Increase, 1 millimetre, Regional, More, Quartzite, Slate

Explanation:

During metamorphic processes, increased pressure and temperature can affect the stability of minerals in rock. Rocks subjected to very high pressure are typically denser than others because mineral grains are squeezed together, and the atoms are more closely packed. During metamorphic processes, water facilitates the transfer of ions between and within minerals, which can increase the rate at which metamorphic reactions take place. The growth of new minerals within a rock during metamorphism has been estimated to be about 1 millimeter per million years. Regional metamorphism is commonly associated with convergent plate boundaries, where two plates move toward each other. During contact metamorphism, a large intrusion will contain more thermal energy and will cool much more slowly than a small one. Metamorphosed sandstone is known as quartzite. The metamorphic rock slate, made from metamorphosed shale, was once used to make blackboards for classrooms.

Answer:

69.8 %.

Explanation:

2Na + Cl2 = 2NaCl

Using Relative Atomic Masses:

2*22.99 g sodium should produce  2*(22.99 + 35.45) =   116.88 g of sodium chloride

So 5.75 g Na should give 116.88 * 5.75 / 2*22.99 g = 14.62 g NaCl

% yield = 10.2 / 14.62 = 69.8%.

2Na + Cl2 = 2NaCl

Using Relative Atomic Masses:

2×22.99 g sodium should produce  2×(22.99 + 35.45) =   116.88 g of sodium chloride

So 5.75 g Na should give 116.88 ×5.75 / 2×22.99 g = 14.62 g NaCl

percentage yield = 10.2 / 14.62 = 69.8%.

Sodium chloride is the chemical name for salt. Sodium is an electrolyte that regulates the amount of water in your body. Sodium also plays a part in nerve impulses and muscle contractions.

Sodium chloride is an essential nutrient and is used in healthcare to help prevent patients from becoming dehydrated. It is used as a food preservative and as a seasoning to enhance flavor.

Sodium chloride is also used in manufacturing to make plastics and other products. It is also used to de-ice roads and sidewalks.

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Nuclear fission is a nuclear reaction where a nucleus absorbs a neutron and splits into two smaller nuclei, releasing energy and more neutrons, which can cause a chain reaction. It's used in nuclear reactors and nuclear weapons.

Nuclear fission is the process in which a nucleus absorbs a neutron and splits into two lighter nuclei, known as fission fragments, releasing a significant amount of energy. This reaction is exothermic, meaning it releases energy in the form of heat, gamma rays, and the kinetic energy of additional neutrons.

These free neutrons may go on to induce fission in other nuclei, creating a chain reaction. A critical aspect of fission is that a minimum amount of fissile material, known as the critical mass, is necessary for a sustained chain reaction to occur. Therefore, the correct option that describes this process is 'A nucleus collides with a neutron and splits, releasing energy.'

The enormous energy release from fission makes it the foundational principle behind nuclear reactors and nuclear weapons. The fission of heavy elements like uranium or plutonium is harnessed as a heat source in nuclear power plants to produce electricity or to drive explosive reactions in atomic bombs.

Answer:

D : Nuclei combine to form a heavier nucleus, releasing energy.

Explanation:

Nuclear fusion is a process by which two or more atomic nuclei combine to form one or more different atomic nuclei and subatomic particles. The nuclei usually involved are deuterium and tritium, which are hydrogen variants. The difference in mass between the reactants and products is manifested as either the release or absorption of energy. Fusion reactions take place in a state of matter called plasma, which is a hot, charged gas made of positive ions and free-moving electrons. Fusion reactions release massive amounts of energy, and this is the same process that powers the sun

Answer:

Dependent variable

Explanation:

Answer:

A variable

Explanation:

A variable is data that changes, two examples are an independent variable and a dependent variable.

Answer:

The options are missing, so I will answer the question in a general manner.

This group of elements includes the alkali metals, alkaline earth metals, transition metals, basic metals, lanthanides and actinides. Depending on conditions, elements belonging to the metalloid group may behave like metals.  So, if you want to know if an element is a metal, just found it in the periodic table.

When bonding with nonmetals in ionic compounds, they are converted into cations. When bonding together they make metallic compounds. When multiple metals bound they form alloys (these can include nonmetals too).

Answer: OA is a balanced equation.

Explanation: For an equation to be balanced, the number of atoms and the total charge of each element in the reaction, of the product and reactant side must be the same.

Considering OA; 6 atoms of nitrogen is present in the reactant side. Shifting to the product side, 6 atoms of nitrogen is also present. Taking the other element in the reaction into account, the number of atoms of each element balances on both sides.

ANSWER:

The correct answer is OA. 2NH3 (g) + 3Mg (s) →3H2 (g) + Mg3N2 (s)

The Equation; 2NH3 (g) + 3Mg (s) →3H2 (g) + Mg3N2 (s), is a balanced chemical equation.

FURTHER EXPLANATION;

According to the law of conservation of mass, all chemical equations should be written such that the mass of the reactants is equal to the mass of the products.

This is done by balancing the chemical equation.

Balancing of chemical equations is a try and error method that makes sure the number of atoms of each element in a chemical equation are equal on the side of the reactants and that of products.

The equation; 2NH3 (g) + 3Mg (s) →3H2 (g) + Mg3N2 is said to be balanced since the number of atoms of each element are equal on both side of the equation.

That is; 2 atoms of nitrogen, 6 atoms of hydrogen and 3 atoms of magnesium on both side of the equation.

Choice OB is incorrect because, the equation 4NH3 (g) + Mg(s)* - H2(g) + Mg3N2 (s) is not balanced as the number of nitrogen atoms and that of hydrogen atoms are not equal on both side of the equation.(4 nitrogen atoms on the reactant side and 2 nitrogen atoms on the product side, 12 hydrogen atoms on the reactant side and 2 hydrogen atoms on the product side).

Choice OC is incorrect because, the equation, NH3 (g) + Mg (s) - H2 (g) + Mg3N2 (s) is not balanced as the number of nitrogen atoms, magnesium atoms and that of hydrogen atoms are not equal on both side of the equation.(1 nitrogen atom on the reactant side and 2 nitrogen atoms on the product side, 3 hydrogen atoms on the reactant side and 2 hydrogen atoms on the product side, 1 magnesium atom on the reactant side and 3 magnesium atom on the product side).

Choice OD is incorrect because, the equation Ca (s) + 02 (9) - 2Cao (s) is not balanced as the number calcium atoms is not the same on both side of the equation, 1 calcium atom on the reactant side and 2 calcium atoms on the product side.

Answer:

1. There are many branches of chemistry or chemistry disciplines. The five main branches are organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry, and biochemistry.

2. 25mg

The question regarding the percentage purity of glucose falls under the domain of analytical chemistry, a branch of chemistry focused on analyzing substances to ascertain their composition and purity. It involves calculating the ratio of the pure substance's mass to the sample's total mass and converting this into a percentage.

The question about identifying the percentage purity of glucose pertains to the branch of chemistry known as analytical chemistry. This field is crucial for quantitatively and qualitatively analyzing substances to determine their composition and purity. To find the percentage purity of a sample, one would typically use the formula:

%purity = (mass of compound / mass of sample) × 100

For instance, if you're analyzing glucose, you'll first need to determine the total mass of the glucose sample you're evaluating. After that, you conduct an experiment or analysis to ascertain the mass of pure glucose within that sample. Once you have both values, you substitute them into the equation to calculate the percent purity of the glucose. This allows chemists to ensure that the concentration of glucose or any other substance is within the required specifications for its intended use, whether that be for consumption, industrial applications, or research.

Such analysis is vital for ensuring the safety and effectiveness of products, maintaining quality control, and complying with legal standards for purity and composition.

Answer:

D

Explanation:

It was later identified that atoms of the same element can be different. This is mostly seen in elements with different isotopes. An example is carbon-14 and carbon-12 that have different masses due to differences in neutrons numbers in their nuclei.

Atoms are also divisible into subatomic particles. Today, atoms can be smashed apart into neutrons, protons and electrons particles. This also occurs naturally in radioactive decay.

It was later identified that atoms of the same element can be different. This is mostly seen in elements with different isotopes. The correct option is D.

Thus, An example is carbon-14 and carbon-12 that have different masses due to differences in neutrons numbers in their nuclei.

Atoms are also divisible into subatomic particles. Today, atoms can be smashed apart into neutrons, protons and electrons particles. This also occurs naturally in radioactive decay.

John Dalton, an English physicist and chemist, proposed the atomic hypothesis in 1808 as a scientific theory about the composition of matter. It claimed that tiny, indivisible particles called "atoms" make up all substance.

According to Dalton's atomic theory, atoms, which are indestructible and indivisible building blocks, make up all substances. Unlike other elements, which have atoms of different sizes and weights, an element's atoms have all the same size and mass.

Thus, It was later identified that atoms of the same element can be different. This is mostly seen in elements with different isotopes. The correct option is D.

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The ideal gas law states: [tex]PV=nRT[/tex]

If we put in the data.

[tex]

1\cdot7=n\cdot8.31\cdot294 \\

n=\boxed{2.865\cdot10^{-3}mol}=\boxed{2.865mmol}

[/tex]

Hope this helps.

r3t40

Using the ideal gas law PV = nRT, the number of moles of air in a 3 L container at 1 atm and 294 K is calculated to be approximately 0.124 moles.

Calculating Moles of Air Using the Ideal Gas Law

To find the number of moles of air in a 3 L container at 1 atm pressure and 294 K, we can use the ideal gas law, PV = nRT. We are given the following values: P (pressure) = 1 atm, V (volume) = 3 L, T (temperature) = 294 K. We can use R (the ideal gas constant) = 0.08206 L-atm/mol-K, which is appropriate for the units provided.

Step-by-step solution:

After doing the math, we find that the number of moles n of air is approximately 0.124 moles.

Answer:

a pure substance and an element

Explanation:

A drop of liquid mercury be described as a pure substance and an element.

Mercury is one of the known elements in the periodic table. The drop of liquid mercury is pure since it has constant and definite composition as well as distinct chemical properties.

A drop of liquid mercury can be described as dense, metallic, and silver. It remains liquid at room temperature due to its low melting point, has high surface tension leading to spherical drops, and is significantly denser than water.

A drop of liquid mercury can be described as a dense, metallic liquid that is silver in color. It is unique among metals because it has a melting point of -38.83 degrees Celsius (-37.89 degrees Fahrenheit), which allows it to be liquid at room temperature. Mercury has a high surface tension, which causes it to form spherical droplets when placed on a surface.

Because mercury does not wet most other materials, it often forms a strong meniscus when in a container, which is the curved surface you see at the top of the liquid. Additionally, mercury has a high density, about 13.6 times that of water, which explains its heavy weight even in small amounts. This high density also means that objects that would normally sink in water might instead float on a surface of mercury.

As a reminder, while mercury is fascinating to study and observe, it is also toxic and can lead to mercury poisoning if handled improperly. Mercury exposure must always be minimized, and any mercury spills should be addressed with appropriate safety protocols.

Answer:

GAS

Explanation:

Answer:

Gas

Explanation:

The gaseous state of matter is highly compressible. According to the kinetic theory of matter, in the gaseous state, gas molecules largely move independent of each other and experience very little intermolecular forces between them.

Gases are abundant in the atmosphere near the earth's surface.

Answer:

second one

Explanation:

Answer:

5.0 x 10⁹ years.

Explanation:

k = ln(2)/(t1/2) = 0.693/(t1/2).

Where, k is the rate constant of the reaction.

t1/2 is the half-life of the reaction.

∴ k =0.693/(t1/2) = 0.693/(1.251 × 10⁹ years) = 5.54 x 10⁻¹⁰ year⁻¹.

kt = ln([A₀]/[A]),

where, k is the rate constant of the reaction (k = 5.54 x 10⁻¹⁰ year⁻¹).

t is the time of the reaction (t = ??? year).

[A₀] is the initial concentration of (K-40) ([A₀] = 100%).

[A] is the remaining concentration of (K-40) ([A] = 6.25%).

∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = ln((100%)/( 6.25%))

∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = 2.77.

∴ t = 2.77/(5.54 x 10⁻¹⁰ year⁻¹) = 5.0 x 10⁹ years.

Answer:

[tex]\boxed{4.99 \times10^{9} \text{ y}}[/tex]

Explanation:

The half-life of potassium-40 (1.248 ×10⁹ y) is the time it takes for half of it to decay.  

After one half-life, half (50 %) of the original amount will remain.  

After a second half-life, half of that amount (25 %) will remain, and so on.  

We can construct a table as follows:  

[tex]\begin{array}{cccc}\textbf{No. of} & &\textbf{Fraction} &\textbf{Percent}\\ \textbf{Half-lives} & \textbf{t/(10$^{9}$ y}) &\textbf{Remaining} &\textbf{Remaining}\\0 & 0 & 1 & 100\\\\1 & 1.248 & \dfrac{1}{2} & 50\\\\2 & 2.496 & \dfrac{1}{4} & 25\\\\3 & 3.744 & \dfrac{1}{8} & 12.5\\\\4 & 4.992 & \dfrac{1}{16} & 6.25\\\\5 & 6.240 & \dfrac{1}{32} & 3.125\\\\\end{array}[/tex]

We see that after four half-lives, ¹/₁₆ or 6.25 % of the original mass remains.

Conversely, if 6.25 % of the sample remains, the age of the sample must be four half-lives.

[tex]\text{Age of rock} = 4 \times 1.248 \times 10^{9}\text{ y}= \boxed{\mathbf{4.99 \times 10^{9}} \textbf{ y}}[/tex]

Hello There!

0.0045 Inches are larger than centimeters.

Answer:

13.28 mol.

Explanation:

where, P is the pressure of the gas in atm (P = 1.32 atm).

V is the volume of the gas in L (V = 242.0 L).

n is the no. of moles of the gas in mol (n = ??? mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K).

T is the temperature of the gas in K (T = 20.0° + 273 = 293.0 K).

∴ n = PV/RT = (1.32 atm)(242.0 L)/(0.0821 L.atm/mol.K)(293.0 K) = 13.28 mol.

Answer:

0.009 mol.

Explanation:

M = (no. of moles of acetic acid)/(Volume of the solution (L)).

M = 0.9 M, Volume of the solution = 10.0 mL = 0.01 L.

∴ no. of moles of acetic acid = (M)(Volume of the solution (L)) = (0.9 M)(0.01 L) = 0.009 mol.

Answer:

The number of acetic acid moles is 0.0090 in 10 ml of the solution​.

Explanation:

[tex]Molarity=\frac{Moles}{Volume (L)}[/tex]

Let the moles acetic acid in vinegar be n.

Molarity of the vinegar solution = 0.90 M

Volume of the vinegar solution = 10 mL = 0.010 L

1 mL = 0.001 L

[tex]0.90M=\frac{n}{0.010 L}[/tex]

[tex]n=0.90 M\times 0.010 L=0.0090 mol[/tex]

The number of acetic acid moles is 0.0090 in 10 ml of the solution​.

Answer:

Explanation:

The combined gas law is also known as general gas law and it is the reduction of the ideal gas equation. In the combined gas law, we assume that n= 1

              From           PV=nRT

                              [tex]\frac{PV}{T}[/tex] = R (constant) if n= 1

      ∴ [tex]\frac{P_{1} V_{1} }{T_{1} }[/tex] =  [tex]\frac{P_{2} V_{2} }{T_{2} }[/tex] =  [tex]\frac{P_{n} V_{n} }{T_{n} }[/tex]

Answer: Both!

Explanation:

Answer:

The ions are now combining to reduce their concentrations.

Explanation:

PbCl₂(s) ⇄ Pb²⁺(aq) + 2Cl⁻(aq),

It is mentioned that the value of Ksp is 1.8 × 10⁻².

∵ The solubility product is lower for this reaction that means the ions produced are getting combined.

∴ Resulting in reducing the concentration of the ions and increasing the formation of the solid lead chloride.

Answer:

The ions are now combining to reduce their concentrations.

Explanation:

Answer:

b. 2 g/mL

Explanation:

Density=mass/volume.

so: D=10g/5mL

Density=2g/mL

Answer:

The correct answer is option b.

Explanation:

To calculate density of a substance, we use the equation:

[tex]\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}[/tex]

We are given:

Mass of an object = 10 g

Volume of an object  = 5 mL

Density of an object = d

Putting values in above equation, we get:

[tex]d=\frac{10 g}{5 mL}=2 g/mL[/tex]

2 g/mL is the density of an object that has a mass of 10 g and a volume of 5 mL.

Answer:

Lithium batteries are well-known for powering our phones and the latest lightweight laptop computers.

Lithium batteries are popular because they are lightweight, provide a stable voltage, are long-lasting, and are capable of delivering a high amount of current, making them suitable for a variety of applications from consumer electronics to electric vehicles and medical devices.

Lithium batteries are among the most popular types of rechargeable batteries used today. They are commonly found in a wide range of portable electronic devices. Here are some key details about their use and why they are so popular:

Answer:

2. a) 2.67 mol.

  b) 1.33 mol.

3. 4.35 g.

4. 8.67 g.

5. a) 143.86 L.

   b) 251.75 L.

Explanation:

2. Iron reacts with oxygen gas according to the following equation:

4Fe + 3O₂ → 2Fe₂O₃ , If 2 moles of oxygen gas is used in the reaction,

4Fe + 3O₂ → 2Fe₂O₃,

It is clear that 4 mole of Fe react with 3 mole of O₂ to  produce 2 moles of Fe₂O₃.

a) how many moles of iron, Fe, will be required?

using cross multiplication:

3 mol of O₂ require  → 4 mol of Fe, from the stichiometry.

2 mol of O₂ require → ??? mol of Fe.

∴ The no. of moles of of Fe are required = (2 mol)(4mol)/(3 mol) = 2.67 mol.

(b) how many moles of iron(III) oxide, Fe₂O₃, will be produced?

using cross multiplication:

3 mol of O₂ produce → 2 mol of Fe₂O₃, from the stichiometry.

2 mol of O₂ require → ??? mol of Fe₂O₃.

∴ The no. of moles of of Fe₂O₃ are produced = (2 mol)(2 mol)/(3 mol) = 1.33 mol.

3. Potassium sulfate can be prepared by the reaction between dilute sulfuric acid  and potassium carbonate.

H₂SO₄ + K₂CO₃ → K₂SO₄ + CO₂ + H₂O,

Calculate the mass of potassium sulfate that can be prepared from 3.45 g of  potassium carbonate.

H₂SO₄ + K₂CO₃ → K₂SO₄ + CO₂ + H₂O,

It is clear that 1 mole of H₂SO₄ reacts with 1 mole of K₂CO₃ to  produce 1 mole of K₂SO₄, 1 mole of CO₂ and 1 mole of H₂O.

Firstly, we need to calculate the no. of moles of 3.45 g of K₂CO₃:

no. of moles of K₂CO₃ = mass/molar mass = (3.45 g)/(138.205 g/mol) = 0.025 mol.

using cross multiplication:

1 mol of K₂CO₃ produce → 1 mol of K₂SO₄, from the stichiometry.

∴ 0.025 mol of K₂CO₃ produce → 0.025 mol of K₂SO₄.

∴ The mass of K₂SO₄ are produced = (no. of moles of K₂SO₄ produced)(molar mass of K₂SO₄) = (0.025 mol)(174.259 g/mol) = 4.35 g.

4. The reaction between zinc and aqueous chromium(III) nitrate can be represented  by the following equation:

3Zn(s) + 2Cr(NO₃)₃ → 3Zn(NO₃)₂ + 2Cr

If 16.25 g of zinc is used to react with chromium(III) nitrate, calculate the mass of  chromium that will be produced.

3Zn(s) + 2Cr(NO₃)₃ → 3Zn(NO₃)₂ + 2Cr ,

It is clear that 3 mole of Zn reacts with 2 mole of Cr(NO₃)₃ to  produce 3 mole of Zn(NO₃)₂  and 2 mole of Cr.

Firstly, we need to calculate the no. of moles of 16.25 g of Zn:

no. of moles of Zn = mass/atomic mass = (16.25 g)/(65.38 g/mol) = 0.25 mol.

using cross multiplication:

3 mol of Zn produce → 2 mol of Cr, from the stichiometry.

∴ 0.25 mol of Zn produce → ??? mol of Cr.

∴ The no. of moles of Cr are produced = (2 mol)(0.25 mol)/(3 mol) = 0.167 mol.

∴ The mass of Cr are produced = (no. of moles of Cr produced)(atomic mass of Cr) = (0.167 mol)(51.9961 g/mol) = 8.67 g.

5. Ethane, C₂H₆, burns in oxygen gas according to the following equation:

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6H₂O,

If 72 dm³ of ethane gas is completely burnt in oxygen, calculate

(a) the volume of carbon dioxide, measured at room temperature and

pressure produced.

Firstly, we can calculate the no. of moles of 72 dm³ ethane at room temperature and pressure using the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm (P = 1.0 atm).

V is the volume of the gas in L (V = 72.0 dm³ = 72.0 L).

n is the no. of moles of the gas in mol (n = ??? mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K),

T is the temperature of the gas in K (T = 298.0 K, room temperature).

∴ n of ethane = PV/RT = (1.0 atm)(72.0 L)/(0.0821 L.atm/mol.K)(298.0 K) = 2.94 mol.

So, we can calculate the no. of moles of CO₂:

using cross multiplication:

2 mol of C₂H₆ produce → 4 mol of CO₂, from the stichiometry.

∴ 2.94 mol of C₂H₆  produce → ??? mol of CO₂.

∴ The no. of moles of CO₂ are produced = (2.94 mol)(4.0 mol)/(2 mol) = 5.88 mol.

∴ The volume of moles of CO₂ are produced = nRT/P = (5.88 mol)(0.0821 L.atm/mol.K)(298.0 K)/(1.0 atm) = 143.86 L.

(b) the volume of oxygen, measured at room temperature and pressure

required​.

using cross multiplication:

2 mol of C₂H₆ require → 7 mol of O₂, from the stichiometry.

∴ 2.94 mol of C₂H₆  require → ??? mol of O₂.

∴ The no. of moles of O₂ are required = (2.94 mol)(7.0 mol)/(2 mol) = 10.29 mol.

∴ The volume of moles of O₂ are produced = nRT/P = (10.29 mol)(0.0821 L.atm/mol.K)(298.0 K)/(1.0 atm) = 251.75 L.