Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce 0.166 g of water and 0.403 g of carbon dioxide. What is the empirical formula for valproic acid?

Propenoic acid, C₃H₄O₂, is a reactive organic liquid that is used in the manufacturing of plastics, coatings, and adhesives. An unlabeled container is thought to contain this liquid. A 0.275-g sample of the liquid is combusted to produce 0.102 g of water and 0.374 g carbon dioxide. Is the unknown liquid propenoic acid? Support your reasoning with calculations.

Washing soda, a compound used to prepare hard water for washing laundry, is a hydrate, which means that a certain number of water molecules are included in the solid structure. Its formula can be written as Na2CO3 # xH2O, where x is the number of moles of H2O per mole of Na2CO3. When a 2.558-g sample of washing soda is heated at 125 C, all the water of hydration is lost, leaving 0.948 g of Na2CO3. What is the value of x?

Epsom salts, a strong laxative used in veterinary medicine, is a hydrate, which means that a certain number of water molecules are included in the solid structure. The formula for Epsom salts can be written as MgSO4 # xH2O, where x indicates the number of moles of H2O per mole of MgSO4. When 5.061 g of this hydrate is heated to 250 C, all the water of hydration is lost, leaving 2.472 g of MgSO4. What is the value of x?

Hydrofluoric acid, HF(aq), cannot be stored in glass bottles because compounds called silicates in the glass are attacked by the HF(aq). Sodium silicate (Na₂SiO₃), for example, reacts as follows: Na₂SiO₃(s) + 8 HF(aq) → H₂SiF₆(aq) + 2 NaF(aq) + 3 H₂O(l) (a) How many moles of HF are needed to react with 0.300 mol of Na₂SiO₃? (b) How many grams of NaF form when 0.500 mol of HF reacts with excess Na₂SiO₃? (c) How many grams of Na₂SiO₃ can react with 0.800 g of HF?

The reaction between potassium superoxide, KO2, and CO2, 4 KO2 + 2 CO2¡2K2CO3 + 3 O2 is used as a source of O2 and absorber of CO2 in selfcontained breathing equipment used by rescue workers. (a) How many moles of O2 are produced when 0.400 mol of KO2 reacts in this fashion?

The reaction between potassium superoxide, KO2, and CO2, 4 KO2 + 2 CO2¡2K2CO3 + 3 O2 is used as a source of O2 and absorber of CO2 in selfcontained breathing equipment used by rescue workers. (b) How many grams of KO2 are needed to form 7.50 g of O2?

Several brands of antacids use Al1OH23 to react with stomach acid, which contains primarily HCl: Al(OH)₃(s) + HCl(aq) → AlCl₃(aq) + H₂O(l) (b) Calculate the number of grams of HCl that can react with 0.500 g of Al(OH)₃. (c) Calculate the number of grams of AlCl₃ and the number of grams of H₂O formed when 0.500 g of Al(OH)₃ reacts.

An iron ore sample contains Fe₂O₃ together with other substances. Reaction of the ore with CO produces iron metal: Fe₂O₃(s) + CO(g) → Fe(s) + CO₂(g) (b) Calculate the number of grams of CO that can react with 0.350 kg of Fe₂O₃. (c) Calculate the number of grams of Fe and the number of grams of CO₂ formed when 0.350 kg of Fe₂O₃ reacts.

Aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulfide. (a) Write the balanced chemical equation for this reaction. (b) How many grams of aluminum hydroxide are obtained from 14.2 g of aluminum sulfide?

Calcium hydride reacts with water to form calcium hydroxide and hydrogen gas. (a) Write a balanced chemical equation for the reaction.

Calcium hydride reacts with water to form calcium hydroxide and hydrogen gas. (b) How many grams of calcium hydride are needed to form 4.500 g of hydrogen?

Automotive air bags inflate when sodium azide, NaN3, rapidly decomposes to its component elements: 2 NaN31s2¡2 Na1s2 + 3 N21g2 (c) How many grams of NaN3 are required to produce 10.0 ft3 of nitrogen gas, about the size of an automotive air bag, if the gas has a density of 1.25 g/L?

The complete combustion of octane, C8H18, a component of gasoline, proceeds as follows: 2 C₈H₁₈(l) + 25 O₂(g) → 16 CO₂(g) + 18 H₂O(g) (a) How many moles of O₂ are needed to burn 1.50 mol of C₈H₁₈?

The complete combustion of octane, C8H18, a component of gasoline, proceeds as follows: 2 C₈H₁₈(l) + 25 O₂(g) → 16 CO₂(g) + 18 H₂O(g) (b) How many grams of O₂ are needed to burn 10.0 g of C₈H₁₈?

The complete combustion of octane, C₈H₁₈, a component of gasoline, proceeds as follows: 2 C₈H₁₈ (l) + 25 O₂ (g) → 16 CO₂ (g) + 18 H₂O (g) (c) Octane has a density of 0.692 g/mL at 20 °C. How many grams of O₂ are required to burn 15.0 gal of C₈H₁₈ (the capacity of an average fuel tank)?

The complete combustion of octane, C₈H₁₈, a component of gasoline, proceeds as follows: 2 C₈H₁₈(l) + 25 O₂(g) → 16 CO₂(g) + 18 H₂O(g). (d) How many grams of CO₂ are produced when 15.0 gal of C₈H₁₈ are combusted? (d) How many grams of CO₂ are produced when 15.0 gal of C₈H₁₈ are combusted?

Detonation of nitroglycerin proceeds as follows: 4 C3H5N3O91l2¡ 12 CO21g2 + 6 N21g2 + O21g2 + 10 H2O1g2 (a) If a sample containing 2.00 mL of nitroglycerin 1density = 1.592 g>mL2 is detonated, how many moles of gas are produced?

The combustion of one mole of liquid octane, CH3(CH2)6CH3, produces 5470 kJ of heat. Calculate how much heat is produced if 1.000 gallon of octane is combusted.

(a) Define the terms limiting reactant and excess reactant.

(b) Why are the amounts of products formed in a reaction determined only by the amount of the limiting reactant?

(c) Why should you base your choice of which compound is the limiting reactant on its number of initial moles, not on its initial mass in grams?

(a) Define the terms theoretical yield, actual yield, and percent yield.

(b) Why is the actual yield in a reaction almost always less than the theoretical yield?

(c) Can a reaction ever have 110% actual yield?

Consider the mixture of ethanol, C2H5OH, and O2 shown in the accompanying diagram. (b) Which reactant is the limiting reactant?

Consider the mixture of ethanol, C2H5OH, and O2 shown in the accompanying diagram. (c) How many molecules of CO2, H2O, C2H5OH, and O2 will be present if the reaction goes to completion?

Consider the mixture of propane, C3H8, and O2 shown here. (a) Write a balanced equation for the combustion reaction that occurs between propane and oxygen.

Consider the mixture of propane, C3H8, and O2 shown here. (c) How many molecules of CO2, H2O, C3H8, and O2 will be present if the reaction goes to completion?