Chemistry Semester 2 Final Review
The Greek letter ∆ stands for...
"change in."
Which compound dissociates to produce the ions SO4 and NH4?
(NH4)2SO4(s)
Which of the following values for heat of solution at 25ºC represents the greatest release of energy?
-3.59kJ/mol
Which expression represents the pH of a solution?
-log[H3O]
What is the molarity of a solution that contains 0.202 mol KCL in 7.98 L solution?
0.0253 M
Calculate the molarity of a Ba(OH)2 solution if 1900 mL is completely titrated by 261 mL of 0.505 M HNO3.
0.0347 M
In the equation C+O2(g)≥CO2(G), one volume of O2 yields how many volumes of CO2?
1
On a cold winter morning when the temperature is -13ºC, the air pressure in an automobile tire is 1.5 atm. If the volume does not change, what is the pressure after the tire has warmed to 15ºC?
1.7 atm.
The pressure of a sample of gas of constant volume is 2.0 atm at 30.0ºC. What is the pressure of this sample at 20.0ºC?
1.9 atm.
The pH of a solution is 10. What is its OH concentration?
10^-4 M
A 150.0 L sample of gas is collected at 1.20 atm and 25ºC. What volume does the gas have at 1.50 atm and 20.0ºC?
120 L
At 7.0ºC, the volume of a gas is 49 mL. At the same pressure, its volume is 74 mL at what temperature?
150ºC.
A 75.0 mL sample of gas exerts 200 mm Hg pressure at 30.0ºC. What pressure does i exert at 35.0ºC if the volume expands to 80.0 mL?
190 mm Hg.
In the reaction 2H2(g)+O2(g)≥2H2O(g), what is the volume ratio of H2 to H2O?
1:1
In the reaction H2(g)+Cl2(g)≥2HCl, what is the volume ratio of H2 to Cl2?
1:1
If 72.1 mL of 0.543 M H2SO4 completely titrates 39.0 mL of KOH solution, what is the molarity of the KOH solution?
2.01 M
Convert the pressure 2.50 atm to kPa.
253 kPa
How much energy is absorbed as heat by 20 g of gold when it is heated form 25ºC to 35ºC? The specific heat of gold is 0.13 J/gºC.
26 J
The equation for the production of methane is C+2H2(g)≥CH4(g). How many liters of hydrogen are needed to produce 20 L of methane?
40 L
The pressure of a sample of helium is 2.0 atm in a 200-mL container. If the container is compressed to 10 mL without changing the temperature, what is the new pressure?
40 atm.
The volume of a gas is 400 mL at 30.0ºC. If the temperature is increased to 50.0ºC without changing the pressure, what is the new volume of the gas?
426 mL.
Convert the pressure 0.600 atm to mm Hg.
456 mm Hg.
If the temperature of 50.0 L of a gas at 40.0ºC falls by 10.0ºC, what is the new volume of the gas if the pressure is constant?
48.4 L
A gas sample with a mass of 2.50 g is collected at 20.0ºC and 732.5 mm Hg. The volume is 1.28 L. What is the molar mass of the gas?
48.8 g/mol
A 425 mL sample of gas is collected at 780 mm Hg. If the temperature remains constant and the pressure falls to 680 mm Hg, what is the new volume?
488 mL
If five gases in a cylinder each exert 1 atm, what is the total pressure exerted by the gases?
5 atm.
The equation for the complete combustion of methane is CH4(g)+2O2(g)≥2H2O(g)+CO2(g). If 50 L pf methane of STP are burned, what volume of carbon dioxide will be produced at STP?
50 L
A sample of gas is collected by water displacement at 600.0 mm Hg and 30.0ºC. What is the partial pressure of the gas?
568.2 mm Hg
A sample of a gas collected at 750 mm Hg occupies 250 mL. At constant temperature, what pressure does the gas exert if the volume increases to 300 mL?
625 mm Hg.
What is the pH of a neutral solution at 25ºC?
7
What is the partial pressure of water vapor in oxygen gas collected by water displacement at 10ºC and 750 mm Hg?
9.2 mm Hg.
A sample of argon gas at standard pressure occupies 1000 mL. At constant temperature, what volume does the gas occupy if the pressure increases to 800 mm Hg?
950 mL.
What units are used to measure specific heat?
All of the above.
Which statement correctly describes the energy changes that occur when bonds form and when bonds break?
Breaking bonds is endothermic, and forming bonds is exothermic.
The reaction of two volume of hydrogen gas with one volume of oxygen gas to produce two volumes of water vapor is an example of...
Gay-Lussac's law of combining volumes of gases.
Which of the following is NOT an oxyacid?
H2O2
Which of the following is a triprotic acid?
H3PO4
Which of the following is a binary acid?
HBr
What is the initial step in the formation of hydrogen iodide from its elements?
I2(g)≥2I(g)
Which of the following statements about freezing is NOT correct?
Not all liquids freeze.
All of the following equations are statements of the ideal gas law except...
P=nRTV
Why are water molecules polar?
The electrons in the covalent bonds spend more time closer to the oxygen nucleus.
Why is ice less dense than liquid water?
The locales in liquid water can crowd together more compactly than in ice.
If "V" is the original volume, "V1" is the new volume, "T" is the original Kelvin temperature, and "T1" is the new Kelvin temperature, how is Charles's law expressed mathematically?
V1= V(T1/T)
Which is NOT an assumption of the kinetic-molecular theory?
When individual particles collide, energy is transferred.
An aerosol dispenser contains a colloidal dispersion of...
a gas and a liquid.
Which of the following is likely to produce crystals if disturbed?
a supersaturated solution
At pressures greater than 760 mm Hg, water will boil at...
a temperature higher than 100ºC.
Whenever a liquid changes to a vapor, it...
absorbs heat energy from its surroundings.
A metal solution is a(n)...
alloy.
The solubility of gases in liquids...
always increases with increasing pressure.
How is a Celsius temperature reading converted to a Kelvin temperature reading?
by dividing by 273.15
Which process is used to speed up the chemical reactions?
catalysis
The particles in a liquid are usually...
closer together and lower in energy than those in a gas.
For most reactions, particles must...
collide in the proper orientation.
Aqueous solutions of bases...
conduct electricity.
As temperature increases, solubility of gases in liquids...
decreases.
As the atmospheric pressure on the surface of a liquid decreases, its boiling point...
decreases.
Ions are formed from solute molecules by the action of the solvent in a process called...
dissociation.
Molecular substances contain...
either polar-covalent or non polar-covalent bonds.
Which of the following is true in an exothermic reaction?
energy of products < energy of reactants < activation energy
What can happen when the average energy of a liquid's particles decreases?
freezing
Pressure has the greatest effect on the solubility of...
gases and liquids.
What is the energy released or absorbed as heat when one mole of a compound is produced by combination of its elements?
heat of formation
The quantity of energy released or absorbed as heat during a chemical reaction is called the...
heat of reaction.
Water molecules freeze in which definite pattern?
hexagonal
Diffusion between two gasses occurs most rapidly if the gases are at a...
high temperature and the molecules are small.
In ice, what holds H2O molecules together?
hydrogen bonds
Which of the following is a molecular substance who's water solution conducts electricity?
hydrogen chloride
Raising the temperature of reactants in a system...
increases the average molecular motion.
A substance that is NOT soluble in a polar solvent is...
ionic.
To conduct electricity, a solution must contain...
ions.
If [H3O] of a solution is greater than [OH], the solution...
is always acidic.
A water solution whose pH is 7...
is always neutral.
The density of a substance undergoes the greatest change when the substance changes from a...
liquid to gas.
The compressibility of solids is generally...
lower than the compressibility of liquids and gases.
The value of R, the ideal gas constant, can be calculated from measured values of a gas's pressure, volume, temperature, and...
molar amount.
When pressure, volume, and temperature are known, the ideal gas law can be used to calculate...
molar amount.
Which of the following is expressed in grams of solute instead of moles of solute?
neither a nor b (molality) & (molarity)
According to the kinetic-molecular theory, particles of a gas...
neither attract nor repel each other but collide.
An acid-base titration is carried out by monitoring...
pH.
Catalysts generally affect chemical reactions by...
providing an alternate pathway with a lower activation energy.
Acids make litmus paper turn...
red.
Bases feel...
slippery.
Sugar in water is an example of which solute-solvent combination?
solid-liquid
The Tyndall effect is used to distinguish between...
solutions and colloids.
Acids taste...
sour.
Strong bases are...
strong electrolytes.
Which of the following is a non-electrolyte?
sugar
What determines the average kinetic energy of the molecules of any gas?
temperature
If the height of mercury in a barometer at 0ºC is less than 760 mm Hg, then...
the atmospheric pressure is less than standard atmospheric pressure.
Changing the temperature affects the rate of reaction because it affects...
the frequency of collision and the number of effective collisions.
The solubility of a solute depends on...
the nature of the solute and the temperature of the solvent.
If the pressure on the equilibrium system 2CO(g)+O2>2CO2(g) is increased...
the quantity of CO2(g) increases.
If gas A has a molar mass greater than that of gas B and samples of each gas at identical temperatures and pressures contain equal numbers of molecules, then...
the volumes of gas A and gas B are equal.
What process measures the amount of a solution of known concentrations required to react with a measured amount of a solution of unknown concentration?
titration
Which of the following does NOT increase the rate of dissolving a solid in water?
using larger pieces of solid
Pure water contains...
water molecules, hydronium ions, and hydroxide ions.
If the water molecules were no polar, it is likely that...
water would be a gas at room temperature.
The conjugate of a strong acid is a...
weak base.