Question 1

What is the relative molecular mass of the compound trinitrotoluene, C₇H₅N₃O₆ (on the ¹²C scale)?

Accepted Answer

The molecular formula for trinitrotoluene (TNT) is C7H5N3O6. Calculating its molar mass: C (12.01) * 7 + H (1.01) * 5 + N (14.01) * 3 + O (16.00) * 6 = 227.13.

Question 2

Vitamin B₁₂, cyanocobalamin, has the molecular formula, C₆₈H₈₈CoN₁₄O₁₄P. What is the percent mass of cobalt in this compound?

Accepted Answer

To find the percent mass of cobalt in cyanocobalamin, first calculate the molar mass of the entire compound and then find the mass percentage of cobalt. The molecular formula is C63H88CoN14O14P. The molar mass of the compound can be calculated by adding the molar masses of each element: C (12.01 g/mol) * 63 + H (1.008 g/mol) * 88 + Co (58.93 g/mol) * 1 + N (14.01 g/mol) * 14 + O (16.00 g/mol) * 14 + P (30.97 g/mol) * 1. The total molar mass is approximately 1355.36 g/mol. The mass of cobalt is 58.93 g/mol. The percent mass of cobalt is (58.93 / 1355.36) * 100 ≈ 4.35%.

Question 3

For the given unbalanced reaction X CaO(s) + y H₂O(l) $\rightarrow$ z Ca(OH)₂ The correct stiochiometric coefficients x, y, & z are

Accepted Answer

The balanced chemical equation is CaO(s) + H₂O(l) → Ca(OH)₂, which corresponds to coefficients x=1, y=1, z=1.

Question 4

In fermentation, sucrose, C₁₂H₂₂O₁₁, reacts with water to form ethanol, C₂H₅OH, and carbon dioxide. A balanced chemical equation for this reaction is?

Accepted Answer

The answer of In fermentation, sucrose, C₁₂H₂₂O₁₁, reacts with water...

Question 5

Calcium carbide, CaC₂, reacts with water to produce calcium hydroxide and acetylene gas, C₂H₂. CaC₂(s) + 2 H₂O(l) $\rightarrow$ Ca(OH)₂(aq) + C₂H₂(g) How many grams of acetylene can be produced from 30.0 g of calcium carbide?

Accepted Answer

First, we need to calculate the molar mass of calcium carbide (CaC2) which is 40.08 (Ca) + 2*12.01 (C) = 64.10 g/mol. Then, we find the molar mass of acetylene (C2H2) which is 2*12.01 (C) + 2*1.01 (H) = 26.04 g/mol. Given 30.0 g of CaC2, we calculate the moles of CaC2 as 30.0 g / 64.10 g/mol = 0.468 moles. The reaction shows a 1:1 mole ratio between CaC2 and C2H2, so 0.468 moles of CaC2 will produce 0.468 moles of C2H2. Finally, we convert moles of C2H2 to grams: 0.468 moles * 26.04 g/mol = 12.18 g, which rounds to 12.2 g.

Question 6

Ammonium perchlorate, NH₄ClO₄, is used with aluminum as rocket fuel. 10 Al(s) + 6 NH₄ClO₄ $\rightarrow$ 4 Al₂O₃ + 2 AlCl₃ + 12 H₂O + 3 N₂ If 100.0 g of aluminum are reacted with 60.0 g of ammonium perchlorate, how many grams of aluminum oxide are produced?

Accepted Answer

First, determine the limiting reactant. The molar mass of aluminum (Al) is approximately 27 g/mol, so 100.0 g of Al is about 3.70 moles. The molar mass of ammonium perchlorate (NH4ClO4) is approximately 117.5 g/mol, so 60.0 g is about 0.51 moles. The balanced chemical equation shows that 10 moles of Al react with 6 moles of NH4ClO4. Therefore, ammonium perchlorate is the limiting reactant. Using stoichiometry, 6 moles of NH4ClO4 produce 4 moles of Al2O3. So, 0.51 moles of NH4ClO4 will produce (0.51 moles NH4ClO4 / 6 moles NH4ClO4) * 4 moles Al2O3 = 0.34 moles Al2O3. The molar mass of Al2O3 is approximately 102 g/mol, so 0.34 moles of Al2O3 is about 34.71 g.

Question 7

Aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulfide by the following reaction Al₂S₃ + 6 H₂O $\rightarrow$ 2Al(OH)₃ + 3H₂S If 25 g of aluminum sulfide is reacted with 25 g of water how many moles of hydrogen sulfide will be formed?

Accepted Answer

First, calculate the moles of aluminum sulfide (Al2S3) and water (H2O) used. The molar mass of Al2S3 is approximately 150.16 g/mol, and for H2O, it is 18.015 g/mol. For 25 g of Al2S3, moles = 25 g / 150.16 g/mol ≈ 0.166 moles. For 25 g of H2O, moles = 25 g / 18.015 g/mol ≈ 1.387 moles. The reaction shows that 1 mole of Al2S3 reacts with 6 moles of H2O to produce 3 moles of H2S. Since Al2S3 is the limiting reagent, it will completely react, and the amount of H2S produced will be directly proportional to the amount of Al2S3. Therefore, 0.166 moles of Al2S3 will produce 0.166 * 3 = 0.498 moles of H2S, which is approximately 0.50 moles.

Question 8

Iron oxide can be reduced to iron by a reaction with carbon to form carbon monoxide Fe₂O₃(s) + 3C(s) $\rightarrow$2Fe(s) + 3CO(g) If 95.0 grams of iron oxide is reacted with excess carbon yields 63 g of iron, what is the percent yield of this reaction?

Accepted Answer

The answer of Iron oxide can be reduced to iron...

Question 9

Acetonitrile, CH₃CN, can be synthesized from carbon monoxide, hydrogen, and ammonia in the presence of a catalyst at high temperatures by the following reaction 2CO(g) + 2H₂(g)+NH₃(g) $\rightarrow$ CH₃CN(g) + 2H₂O(g) If 20 g of carbon monoxide, 20 g of hydrogen, and 10 g of ammonia are reacted, which will be the limiting reagent?

Accepted Answer

The answer of Acetonitrile, CH₃CN, can be synthesized from carbon...

Question 10

Which has a larger molar volume (the volume occupied by one mole): Gold (density = 19.3 g cm^-³) or tin (density = 7.31 g cm^-³)?

Accepted Answer

Tin has a larger molar volume because it has a lower density than gold, meaning a given mass of tin occupies more volume than the same mass of gold.

Question 11

Copper oxide ore, CuO, can be smelted with carbon to make copper metal and carbon dioxide. 2CuO(s) + C(s) $\rightarrow$ 2Cu(s) + CO₂(g) If 100.0 of a mixed ore is smelted and produces 75.9 grams of pure copper. What percentage of the mixed ore is CuO? (You can assume the reaction yield is 100%, there is excess carbon, and that CuO is the only source of copper.)

Accepted Answer

The answer of Copper oxide ore, CuO, can be smelted...

Question 12

A vanadium oxide contains 56.02% vanadium by mass. What is its empirical formula?

Accepted Answer

The answer of A vanadium oxide contains 56.02% vanadium by...

Question 13

Caffeine has the molecular formula, C₈H₁₀N₄O₂. If it is burned in excess oxygen it will form carbon dioxide, water vapor, and nitrogen gas. Which gas will be most abundant by mass?

Accepted Answer

The molecular formula for caffeine is C8H10N4O2. When burned in excess oxygen, it forms CO2, H2O, and N2. The carbon content (C8) will produce the most CO2 by mass, making carbon dioxide the most abundant by mass among the products.

Question 14

Triphenylene is an organic compound containing only carbon and hydrogen with 3 carbon atoms for every two hydrogen atoms. Which of the following is a possible molecular mass for triphenylene?

Accepted Answer

Triphenylene has a molecular formula of C18H12, which gives a molecular mass of approximately 228.29 g/mol.

Question 15

Sodium perbromate can be synthesized via the following reaction that gives off Xenon gas. A reaction is started with 200.0g of NaBrO₃, 250.0g of XeF₂ and 100.0g of water. Assuming that the reaction goes to completion, and that all of the formed xenon gas is allowed to escape into the atmosphere, what will be the minimum mass of products and reactants remaining in the reaction vessel?

Accepted Answer

The answer of Sodium perbromate can be synthesized via the...

Quiz 2: Chemical Formulas, Chemical Equations, and Reaction Yields

What is the relative molecular mass of the compound trinitrotoluene, C₇H₅N₃O₆ (on the ¹²C scale) ?

Vitamin B₁₂, cyanocobalamin, has the molecular formula, C₆₈H₈₈CoN₁₄O₁₄P. What is the percent mass of cobalt in this compound?

For the given unbalanced reaction X CaO(s) + y H₂O(l) $\rightarrow$ z Ca(OH) ₂ The correct stiochiometric coefficients x, y, & z are

In fermentation, sucrose, C₁₂H₂₂O₁₁, reacts with water to form ethanol, C₂H₅OH, and carbon dioxide. A balanced chemical equation for this reaction is?

Calcium carbide, CaC₂, reacts with water to produce calcium hydroxide and acetylene gas, C₂H₂. CaC₂(s) + 2 H₂O(l) $\rightarrow$ Ca(OH) ₂(aq) + C₂H₂(g) How many grams of acetylene can be produced from 30.0 g of calcium carbide?

Ammonium perchlorate, NH₄ClO₄, is used with aluminum as rocket fuel. 10 Al(s) + 6 NH₄ClO₄ $\rightarrow$ 4 Al₂O₃ + 2 AlCl₃ + 12 H₂O + 3 N₂ If 100.0 g of aluminum are reacted with 60.0 g of ammonium perchlorate, how many grams of aluminum oxide are produced?

Aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulfide by the following reaction Al₂S₃ + 6 H₂O $\rightarrow$ 2Al(OH) ₃ + 3H₂S If 25 g of aluminum sulfide is reacted with 25 g of water how many moles of hydrogen sulfide will be formed?

Iron oxide can be reduced to iron by a reaction with carbon to form carbon monoxide Fe₂O₃(s) + 3C(s) $\rightarrow$ 2Fe(s) + 3CO(g) If 95.0 grams of iron oxide is reacted with excess carbon yields 63 g of iron, what is the percent yield of this reaction?

Which has a larger molar volume (the volume occupied by one mole) : Gold (density = 19.3 g cm^-³) or tin (density = 7.31 g cm^-³) ?

A vanadium oxide contains 56.02% vanadium by mass. What is its empirical formula?

Caffeine has the molecular formula, C₈H₁₀N₄O₂. If it is burned in excess oxygen it will form carbon dioxide, water vapor, and nitrogen gas. Which gas will be most abundant by mass?

Triphenylene is an organic compound containing only carbon and hydrogen with 3 carbon atoms for every two hydrogen atoms. Which of the following is a possible molecular mass for triphenylene?

Quiz 2: Chemical Formulas, Chemical Equations, and Reaction Yields

What is the relative molecular mass of the compound trinitrotoluene, C7H5N3O6 (on the 12C scale) ?

Vitamin B12, cyanocobalamin, has the molecular formula, C68H88CoN14O14P. What is the percent mass of cobalt in this compound?

For the given unbalanced reaction X CaO(s) + y H2O(l) →\rightarrow→ z Ca(OH) 2 The correct stiochiometric coefficients x, y, & z are

In fermentation, sucrose, C12H22O11, reacts with water to form ethanol, C2H5OH, and carbon dioxide. A balanced chemical equation for this reaction is?

Calcium carbide, CaC2, reacts with water to produce calcium hydroxide and acetylene gas, C2H2. CaC2(s) + 2 H2O(l) →\rightarrow→ Ca(OH) 2(aq) + C2H2(g) How many grams of acetylene can be produced from 30.0 g of calcium carbide?

Ammonium perchlorate, NH4ClO4, is used with aluminum as rocket fuel. 10 Al(s) + 6 NH4ClO4 →\rightarrow→ 4 Al2O3 + 2 AlCl3 + 12 H2O + 3 N2 If 100.0 g of aluminum are reacted with 60.0 g of ammonium perchlorate, how many grams of aluminum oxide are produced?

Aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulfide by the following reaction Al2S3 + 6 H2O →\rightarrow→ 2Al(OH) 3 + 3H2S If 25 g of aluminum sulfide is reacted with 25 g of water how many moles of hydrogen sulfide will be formed?

Iron oxide can be reduced to iron by a reaction with carbon to form carbon monoxide Fe2O3(s) + 3C(s) →\rightarrow→ 2Fe(s) + 3CO(g) If 95.0 grams of iron oxide is reacted with excess carbon yields 63 g of iron, what is the percent yield of this reaction?

Which has a larger molar volume (the volume occupied by one mole) : Gold (density = 19.3 g cm-3) or tin (density = 7.31 g cm-3) ?

A vanadium oxide contains 56.02% vanadium by mass. What is its empirical formula?

Caffeine has the molecular formula, C8H10N4O2. If it is burned in excess oxygen it will form carbon dioxide, water vapor, and nitrogen gas. Which gas will be most abundant by mass?

Triphenylene is an organic compound containing only carbon and hydrogen with 3 carbon atoms for every two hydrogen atoms. Which of the following is a possible molecular mass for triphenylene?

What is the relative molecular mass of the compound trinitrotoluene, C₇H₅N₃O₆ (on the ¹²C scale) ?

Vitamin B₁₂, cyanocobalamin, has the molecular formula, C₆₈H₈₈CoN₁₄O₁₄P. What is the percent mass of cobalt in this compound?

For the given unbalanced reaction X CaO(s) + y H₂O(l) $\rightarrow$ z Ca(OH) ₂ The correct stiochiometric coefficients x, y, & z are

In fermentation, sucrose, C₁₂H₂₂O₁₁, reacts with water to form ethanol, C₂H₅OH, and carbon dioxide. A balanced chemical equation for this reaction is?

Calcium carbide, CaC₂, reacts with water to produce calcium hydroxide and acetylene gas, C₂H₂. CaC₂(s) + 2 H₂O(l) $\rightarrow$ Ca(OH) ₂(aq) + C₂H₂(g) How many grams of acetylene can be produced from 30.0 g of calcium carbide?

Ammonium perchlorate, NH₄ClO₄, is used with aluminum as rocket fuel. 10 Al(s) + 6 NH₄ClO₄ $\rightarrow$ 4 Al₂O₃ + 2 AlCl₃ + 12 H₂O + 3 N₂ If 100.0 g of aluminum are reacted with 60.0 g of ammonium perchlorate, how many grams of aluminum oxide are produced?

Aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulfide by the following reaction Al₂S₃ + 6 H₂O $\rightarrow$ 2Al(OH) ₃ + 3H₂S If 25 g of aluminum sulfide is reacted with 25 g of water how many moles of hydrogen sulfide will be formed?

Iron oxide can be reduced to iron by a reaction with carbon to form carbon monoxide Fe₂O₃(s) + 3C(s) $\rightarrow$ 2Fe(s) + 3CO(g) If 95.0 grams of iron oxide is reacted with excess carbon yields 63 g of iron, what is the percent yield of this reaction?

Which has a larger molar volume (the volume occupied by one mole) : Gold (density = 19.3 g cm^-³) or tin (density = 7.31 g cm^-³) ?

Caffeine has the molecular formula, C₈H₁₀N₄O₂. If it is burned in excess oxygen it will form carbon dioxide, water vapor, and nitrogen gas. Which gas will be most abundant by mass?