chemistry final exam review (chapters 5-9)

Titration of 25.0 mL of an HCl solution of unknown concentration requires 14.8 mL of 0.100 M NaOH. What is the molar concentration of the HCl solution? NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

0.0592 M

Enough water is added to 50.0 mL of a 0.660 M NaOH solution in order to bring the total volume to 450.0 mL. What is the molarity of this diluted solution?

0.0733 M

Calculate the molar concentration of a sodium hydroxide solution if 60.00 mL of this solution were required to neutralize 30.00 mL of a 0.150 M hydrochloric acid solution. NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

0.0750 M

What percentage of the initial amount of a radioactive isotope will remain after ten half-lives?

0.098%

A chemist needs 0.725 moles of acetic acid for a particular reaction. What volume of a 1.50 M acetic acid solution is needed to provide this amount?

0.483 L

Give the missing symbol to the following nuclear reaction. 11/6 C > 11/5 B + ?

0/+1 e

How many small calories are equivalent to one nutritional Calorie?

1,000

Calculate the density of nitrogen gas (N2) at STP, in g/L. [Molar mass: N2, 28.0 g/mol]

1.25 g/L

What is the osmotic pressure of a 6.0 × 10-2 M NaCl solution at 20°C (293 K)? [R=0.0821 (L•atm)/(mol•K)]

2.9 atm

A sample of oxygen occupies 1.00 L. If the temperature remains constant, and the pressure on the oxygen is decreased to one third the original pressure, what is the new volume?

3.00 L

A 50-mg sample of iodine-131 was placed in a container 32.4 days ago. If its half-life is 8.1 days, how many milligrams of iodine-131 are now present?

3.1 mg

How many half-lives are needed for a 400.0 ng sample of a radioactive isotope to decay to 12.5 ng?

5

A student needs to prepare 250.0 mL of a 2.50 M HCl solution using the stock solution 12.0 M HCl. What volume of 12.0 M HCl is required for this dilution?

52.1 mL

A helium-filled weather balloon is launched from the ground where the pressure is 752 mmHg and the temperature is 21°C. Under these conditions its volume is 75.0 L. When it has climbed to an altitude where the pressure is 89 mmHg and the temperature is 0°C, what is its volume?

588 L

When a sample of aqueous hydrochloric acid was neutralized with aqueous sodium hydroxide in a calorimeter, the temperature of 100.0 g of water surrounding the reaction increased from 25.0°C to 31.5°C. If the specific heat of water is 1.00 cal/(g•°C), calculate the quantity of energy in calories involved in this neutralization reaction.

650 cal

A solution containing a buffer has an initial pH of 8.78. If a student adds 5 drops of NaCl(aq) to this solution, what would be a reasonable pH for the resulting solution?

8.78

Morphine is used medicinally as a pain reliever. If an aqueous solution of morphine has [H3O+] = 1.1 × 10^−10 M, what is the pH of this solution?

9.96

Consider the following generalized buffer solution equilibrium: BH^+(aq) + H2O(l) > H3O^+(aq) + B(aq) When a small amount of a strong base such as sodium hydroxide is added to the solution, which of the four species shown would experience an increase in concentration? (Hint: Use LeChatelier's principle.)

B

Who discovered the gas law represented in the figure shown?

Charles

In the graph shown, which line is the best representation of Boyle's Law regarding behavior of a gas?

E

The species that remains after an acid donates a proton is called its conjugate base. What is the conjugate base of the hydronium ion, H3O^+?

H2O

What is the conjugate base of H2SO4?

HSO4-

Increasing the pressure of a gas over a solution increases the solubility of the gas in the solution. This is an example corresponding to which law?

Henry's Law

Which statement concerning the three states of matter is FALSE?

Particles of a liquid have a rigid, ordered arrangement due to the high speeds of the liquid particles

For the reaction: A(g) → 2B(g), Keq=4.5 × 10^5. Which statement is TRUE for the system at equilibrium?

There is more than 100 times more B than there is A in the reaction vessel

Consider the reversible reaction: N2(g) + 3H2(g) > 2NH3(g) What is the correct expression for the equilibrium constant, Keq, for this reaction?

[NH3]^2/[N2][H2]^3

Which statement about a crystalline solid is always TRUE?

a crystalline solid has a regular repeating structure of the atoms, ions, or molecules that make up the solid

In the potential energy diagram for a chemical reaction, what is the name used for the unstable species corresponding to the top of the energy barrier separating reactants from products?

activated complex

Which of the following statements concerning acids and bases is FALSE?

addition of a base to water increases the hydronium ion concentration of the solution

Which nuclear particle is identical to an He^2+ ion?

alpha

Which type of radiation emitted by radioactive nuclei is the slowest moving and least penetrating?

alpha

What is the name given to the energy that is responsible for holding the protons and neutrons together in the nucleus?

binding energy

When a nuclear reaction is balanced, which of the following is TRUE?

both the sum of the mass numbers and the sum of the atomic numbers are the same on the either side of the reaction

What type of liquid displays the Tyndall effect?

colloidal suspension

What process is responsible for the formation of dew on the grass early in the morning?

condensation

How can pure water be made to boil at a temperature below 100°C?

decrease the pressure below 1 atm

The isotope 99/43 Tc decays to 99/43 Tc by emitting radiation. What type of radiation is emitted?

gamma rays

What state(s) of matter is most compressible?

gas

What type of membrane allows solvent molecules to pass through but does not allow solute molecules to pass through?

semipermeable

Which of the following is a TRUE statement concerning the specific heat of a substance?

specific heat is the amount of heat required to raise one gram of a substance by one degree Celsius

Which statement concerning the relative strength of acids is FALSE?

strong acids produce strong conjugate bases; weak acids produce weak conjugate bases

An unknown amount of water is added to 75 mL of a 3.5 M sodium chloride solution. What can be said for certain about the concentration of the solution that results?

the concentration of the resulting solution will be less than 3.5 M

For the reaction shown below, Keq=2×10^11. Which of the following statements concerning this system at equilibrium is true? 2CO(g) + O2(g) > 2CO2(g)

the equilibrium solution contains predominantly CO2

The solubility of a solute is best described as which of the following?

the maximum amount of solute that can be dissolved in a specified amount of solvent

Phosphorus-31 is a non-radioactive isotope of phosphorus, and phosphorus-32 is a radioactive isotope of phosphorus used in nuclear medicine. Which statement concerning these two isotopes is TRUE?

the non-radioactive isotope has 16 neutrons and the radioactive isotope has 17 neutrons

The formation of rust (Fe2O3) on an exposed piece of metal typically takes several months. Which of the following statements is NOT a reasonable assumption about this chemical reaction? 4Fe(s) + 3O2(g) → 2Fe2O3(s)

the reaction has low activation energy

Ammonia is synthesized industrially by the reaction of nitrogen and hydrogen in the presence of an iron catalyst according to the reaction equation below. What effect would removing the iron catalyst have on this reaction? 3H2(g) + N2(g) >(Fe)> 2NH3(g)

the reaction rate would decrease

A sample of black coffee was measured to have: [H3O^+] = 7.94 × 10^−6. What is TRUE about this solution?

the solution is acidic

How are 0.15 M NaCl, 0.30 M glucose, and intracellular fluids similar?

they are all isotonic

One effect of a catalyst being added to a reaction mixture is

to provide a new pathway for the reaction