All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Additional Problems
2.34 liters of oxygen gas is collected over water at 1.0 atm and 25 °C. What is the mass of the oxygen gas (vapor pressure of water at 25 °C is 24 torr)? A. 1.48 g B. 2.97 g C. 3.06 g D. 3.16 g E. 35.4 g
In the following reaction, 81.2 mL of O 2(g) is collected over water at 23.0°C and a barometric pressure of 751 mm Hg. What must have been the mass in grams of Ag2O(s) decomposed? (The vapor pressure of water at 23.0°C is 21.1 mm Hg). 2 Ag2O(s) → 4 Ag(s) + O2(g)   a) no given answer is close b) 1.49 c) 0.744 d) 2.98 e) 2.07
Binary compounds of alkali metals and hydrogen react with water to liberate H2 (g). The H2 from the reaction of a sample of NaH with an excess of water fills a volume of 0.495 L above the water. The temperature of the gas is 35 oC and the total pressure is 760 mmHg .Find the mass of H2 liberated.
Binary compounds of alkali metals and hydrogen react with water to liberate H2 (g). The H2 from the reaction of a sample of NaH with an excess of water fills a volume of 0.495 L above the water. The temperature of the gas is 35 oC and the total pressure is 760 mmHg .Find the mass of NaH that reacted.
When a gas is collected over water, is the gas pure?
How can the partial pressure of the collected gas be determined?
The hydrogen gas formed in a chemical reaction is collected over water at 30.0 oC at a total pressure of 734 mm Hg .What is the partial pressure of the hydrogen gas collected in this way?
The hydrogen gas formed in a chemical reaction is collected over water at 30.0 oC at a total pressure of 734 mm Hg .If the total volume of gas collected is 724 mL , what mass of hydrogen gas is collected?
Modern pennies are composed of zinc coated with copper. A student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the HCl (the copper remains undissolved): Zn(s) + 2 HCl(aq) → H2(g) + ZnCl(aq)The student collects the hydrogen produced over water at 25 °C. The collected gas occupies a volume of 0.899 L at a total pressure of 79 J mmHg. Calculate the percent zinc (by mass) in the penny. (Assume that all the Zn in the penny dissolves.)  
Consider the reaction:2 Ag2O(s) → 4 Ag(s) + O2(g)If this reaction produces 15.8 g of Ag(s), what total volume of gas can be collected over water at a temperature of 25 °C and a total pressure of 752 mmHg?  
A 500 mL gas sample is collected over water at a pressure of 740 mmHg and 25°C. What is the volume of the dry gas at STP? (STP= 1 atm and 0°C.)Vapor Pressure of H2O at 25°C: 24 mmHg 
A 5.0 L sample of nitrogen gas was collected over water at 60.0°C and a barometric pressure of 1.14 atm. What mass of nitrogen gas was actually collected? At 60.0°C, the vapor pressure of water is 149.3 torr.a) 5.8b) 2.4c) 2.9d) 4.8e) none of the given answers 
The hydrogen gas formed in a chemical reaction is collected over water at 30.0 °C at a total pressure of 732 mm Hg.a. What is the partial pressure of the hydrogen gas collected in this way?b. If the total volume of gas collected is 722 mL, what mass of hydrogen gas is collected? 
Oxygen can be produced in the laboratory by the reaction 2KClO3(s) → 2KCl(s) + 3O2(g) .How much potassium chlorate is needed to produce 2.75 L of oxygen, collected over water at 37°C and 94.9 kPa? The vapor pressure of water at 37°C is 6.28 kPa.1. 0.189 mol2. 9.45 × 10−2 mol3. 0.142 mol4. 7.20 × 10−2 mol5. 6.30 × 10−2 mol
A sample of O2 was collected over water at 45.0°C when the barometric pressure was 872 mm Hg. The volume of the gas collected over the water was 5.34 L. What would the volume of dry O2 be (in liters) at 763 mm Hg and 25.0°C? The vapor pressure of water at 45.0°C is 72 mm Hg.a) none of the given answersb) 5.43c) 3.11d) 4.77e) 5.25
We have prepared acetylene, C2H2 (g), in class by the reaction of calcium carbide with water:  CaC2(s) + 2 H2O(l)  →  Ca(OH)2 (s) + C2H2(g) Calculate the volume of C2H2 that is collected over water at 28.0°C by the reaction of 1.60 g CaC 2 (MM = 64.10g/mol) if the total pressure was 748.0 mmHg. The vapor pressure of water at 28.0°C is 28.3 mmHg.  a) 0.651 L b) 0.424 L c) 0.384 L d) 4.57 L e) 8.03 L 
According to the equation 2 KCIO 3(s) → 2 KCI(s) + 3 O 2(g)A 3.00 g sample of KCIO 3 (122.5 g/mol) decomposes and the oxygen is collected over water at 24.0°C and 0.982 atm. What volume of oxygen gas will be collected, assuming 100% yield? P(H 2O) at 24.0°C = 22.38 Torr.a. 911 mLb. 301 mLc. 605 mLd. 1820 mLe. 940 mL
The hydrogen gas formed in a chemical reaction is collected over water at 30.0 °C at a total pressure of 732 rnmHg. What is the partial pressure of the hydrogen gas collected in this way? If the total volume of gas collected is 722 ml, what mass of hydrogen gas is collected? 
The zinc within a copper-plated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (so that the hydrochloric acid can get to the zinc). The reaction between the acid and the zinc is 2 H+(aq) + Zn(s) → H2(g)+Zn2+(aq). When the zinc in a certain penny dissolves, the total volume of gas collected over water at 25 °C was 0.951 L at a total pressure of 748 mmHg. What mass of hydrogen gas was collected?   
Hydrogen peroxide (H2O2) decomposes in the presence of a catalyst to form water and oxygen. The catalyst is added to 5.00 mL of a hydrogen peroxide solution at 25.0˚C, and 49.5 mL of gas is collected over water at a total pressure of 763.6 mmHg.What is the concentration (in mol/L) of the hydrogen peroxide solution?
One method of analyzing amino acids is the van Slyke method. The characteristic amino groups (−NH2) in protein material are allowed to react with nitrous acid, HNO2, to form N2 gas. From the volume of the gas, the amount of amino acid can be determined. A 0.0604-g sample of a biological sample containing glycine, CH2(NH2)COOH, was analyzed by the van Slyke method and yielded 3.70 mL of N2 collected over water at a pressure of 735 torr and 29 °C. What was the percentage of glycine in the sample? CH2(NH2)CO2H + HNO2 ⟶ CH2(OH)CO2H + H2O + N2
Hydrogen gas is produced when zinc reacts with sulfuric acid:Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g)If 160 mL of wet H2 is collected over water at 24 oC and a barometric pressure of 738 torr, how many grams of Zn have been consumed? (The vapor pressure of water is 22.38 torr.)
Acetylene gas, C2H2(g), can be prepared by the reaction of calcium carbide with water: CaC2(s) + 2 H2O(l) → Ca(OH)2(s) + C2H2(g)Calculate the volume of C2H2 that is collected over water at 23 oC by reaction of 1.53 g of CaC2 if the total pressure of the gas is 753 torr. (The vapor pressure of water is 21.07 torr.)
A common way to make hydrogen gas in the laboratory is to place a metal such as zinc in hydrochloric acid (see the figure). The hydrochloric acid reacts with the metal to produce hydrogen gas, which is then collected over water. Suppose a student carries out this reaction and collects a total of 150.2 mL of gas at a pressure of 746 mmHg and a temperature of 25oC. What mass of hydrogen gas (in mg) does the student collect? (The vapor pressure of water is 23.78 mmHg at 25oC.)
Modern pennies are composed of zinc coated with copper. A student determines the mass of a penny to be 2.483 g and then makes several scratches in the copper coating (to expose the underlying zinc). The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the HCl (the copper remains undissolved):Zn(s) + 2HCl(aq) → H2(g) + ZnCl2(aq)The student collects the hydrogen produced over water at 25 oC. The collected gas occupies a volume of 0.899 L at a total pressure of 791 mm Hg .Calculate the percent zinc in the penny. (Assume that all the Zn in the penny dissolves.)
Consider the following reaction:2 NiO(s) → 2Ni(s) + O2(g)If O2 is collected over water at 40.0 oC and a total pressure of 746 mmHg , what volume of gas will be collected for the complete reaction of 24.79 g of NiO?
The following reaction forms 15.1 g of Ag(s):2 Ag2O(s) → 4 Ag(s) + O2(g)What total volume of gas forms if it is collected over water at a temperature of 25 oC and a total pressure of 753 mmHg ?
In a collision of sufficient force, automobile air bags respond by electrically triggering the explosive decomposition of sodium azide (NaN3) to its elements. A 50.0-g sample of sodium azide was decomposed, and the nitrogen gas generated was collected over water at 26°C. The total pressure was 745.5 mmHg. How many liters of dry N2 were generated?
Aluminum reacts with excess hydrochloric acid to form aqueous aluminum chloride and 35.8 mL of hydrogen gas over water at 27°C and 751 mmHg. How many grams of aluminum reacted?
How many liters of hydrogen gas are collected over water at 18°C and 725 mmHg when 0.84 g of lithium reacts with water? Aqueous lithium hydroxide also forms.
Hydrogen peroxide (H2O2) decomposes in the presence of a catalyst to form water and oxygen. The catalyst is added to 5.00 mL of a hydrogen peroxide solution at 25.0˚C, and 49.5 mL of gas is collected over water at a total pressure of 763.6 mmHg.What is the vapor pressure of water under these conditions.
Hydrogen peroxide (H2O2) decomposes in the presence of a catalyst to form water and oxygen. The catalyst is added to 5.00 mL of a hydrogen peroxide solution at 25.0˚C, and 49.5 mL of gas is collected over water at a total pressure of 763.6 mmHg.What is the partial pressure of oxygen collected over the water?
Hydrogen peroxide (H2O2) decomposes in the presence of a catalyst to form water and oxygen. The catalyst is added to 5.00 mL of a hydrogen peroxide solution at 25.0˚C, and 49.5 mL of gas is collected over water at a total pressure of 763.6 mmHg.How many moles of oxygen are collected?
Hydrogen peroxide (H2O2) decomposes in the presence of a catalyst to form water and oxygen. The catalyst is added to 5.00 mL of a hydrogen peroxide solution at 25.0˚C, and 49.5 mL of gas is collected over water at a total pressure of 763.6 mmHg.How many grams of hydrogen peroxide were in the original sample?
The air in a bicycle tire is bubbled through water and collected at 25 oC. If the total volume of gas collected is 5.50 L at a temperature of 25 oC and a pressure of 746 torr , how many moles of gas was in the bicycle tire?
A sample of carbon monoxide was collected over water at a total pressure of 756 torr and a temperature of 18 °C. What is the pressure of the carbon monoxide? (See Table 9.2 for the vapor pressure of water.)
In an experiment in a general chemistry laboratory, a student collected a sample of a gas over water. The volume of the gas was 265 mL at a pressure of 753 torr and a temperature of 27 °C. The mass of the gas was 0.472 g. What was the molar mass of the gas?
A sample of a liquid hydrocarbon known to consist of molecules with five carbon atoms is vaporized in a 0.204-L flask by immersion in a water bath at 101°C. The barometric pressure is 767 torr, and the remaining gas weighs 0.482 g. What is the molecular formula of the hydrocarbon?
A sample of hydrogen gas was collected over water at 36°C and 855 mm Hg. The volume of the container was 6.50 L. Calculate the mass of H2 (g) collected. (Vapor pressure of water = 44.6 torr at 36°C) a. 0.58 g b. 9.38 g c. 0.55 g d. 4.69 g e. 0.27 g
A piece of sodium metal reacts completely with water as follows:2Na (s) + 2H2O (t) →2NaOH (aq) + H2 (g)The hydrogen gas generated is collected over water at 23.0°C. The volume of the gas is 187 mL measured at 0.981 atm. Calculate the number of grams of sodium used in the reaction. (The vapor pressure of water at 23.0°C = 0.0277 atm.) 
The following reaction forms 14.0 g of Ag(s): 2Ag2O(s) → 4 Ag(s) + O2(g)What total volume of gas forms if it is collected over water at a temperature of 25 ° C and a total pressure of 761 mmHg?
Consider the reaction: 2NiO (s) → 2Ni (s)+ O2 (g) Oxygen gas is collected over water at 40.0°C and a barometric pressure of 745 torr. What volume of oxygen will be collected for the complete reaction of 24.8 g NiO? You must show the key steps in the calculation to get the full credit even for the correct answer.
Consider the following reaction:2NiO(s) → 2Ni(s) + O2(g) If O2 is collected over water at 40.0°C and a total pressure of 744 mmHg, what volume of gas will be collected for the complete reaction of 24.50 g of NiO?
A sample of hydrogen was collected by water displacement at 23.0°C and an atmospheric pressure of 735 mmHg. Its volume is 568 mL. After water vapor is removed, what volume would the hydrogen occupy at the same conditions of pressure and temperature? (The vapor pressure of water at 23.0°C is 21 mmHg.) (a) 509 mL (b) 539 mL (c) 552 mL (d) 568 mL (e) 585 mL
Hydrogen produced from a hydrolysis reaction was colected over water and the following data was compiled. Calculate the moles of hydrogen gas produced by the reaction. 
A common way to make hydrogen gas in the laboratory is to place a metal such as zinc in hydrochloric acid. The hydrochloric acid reacts with the metal to produce hydrogen gas, which is then collected over water. Suppose a student carries out this reaction and collects a total of 169.7 mL of gas at a pressure of 749 mmHg and a temperature of 25°C. What mass of hydrogen gas (in mg) does the student collect? Express your answer using three significant figures.