Chemistry: Acid-Base, Equilibrium, and Oxidation-Reduction Key Concepts

Which anion is not considered basic?

Cl-

Which compound will form a basic solution in water?

All of the above will form basic solutions.

Which cation is not considered acidic?

Na+

Which weak acid has the strongest conjugate base?

hydrocyanic acid, Ka 4.0 x 10-10

What is the Kb for CN at 25°C if the Ka for HCN is 4.9 x 10-10?

2.3 x 10-9

What does a Lewis acid do?

accepts electrons.

What does a Lewis base do?

donates electrons.

What acid does the stomach excrete to kill microorganisms?

HCl

What acid is found in car batteries?

H2SO4

What acid is found in vinegar?

CH3COOH

Which base is in Drano?

NaOH

Which base is in baking soda?

NaHCO3

Which Brønsted-Lowry acid is not considered strong in water?

H2S03

Which compound is generally considered an Arrhenius acid?

H2SO4

Which of the following is a Brønsted-Lowry base?

NH3

What is a good buffer?

small amounts of both a weak acid and its conjugate base

What is buffer capacity?

the amount of acid or base that can be added to a buffer without destroying its effectiveness.

What is true about the equivalence point in a titration?

The amount of acid equals the amount of base.

What is the pH at the equivalence point when titrating a strong monoprotic acid with KOH?

The pH will be less than 7.

What is the best choice for an acid component for a buffer effective at pH 3.00?

Ka equal to 9.10 × 10-4.

What is the pH of a buffer that is 0.225 M HC2H3O2 and 0.162 M KC2H3O2?

4.60

What is the pH of a buffer that is 0.200 M H3BO3 and 0.122 M KH2B03?

9.02

What is the pH of a solution formed by mixing 250.0 mL of 0.15 M NH4Cl with 100.0 mL of 0.20 M NH3?

8.98

What is the strongest acid among the following?

HIO4.

What is true about an effective buffer?

A buffer is most resistant to pH change when [acid] = [conjugate base].

What is the pH at the equivalence point when titrating a strong monoprotic acid with KOH at 25°C?

7

What is the pH at the equivalence point when titrating a weak monoprotic acid with NaOH at 25°C?

Greater than 7

What is the pH at the equivalence point when titrating a monoprotic strong acid with a weak base at 25°C?

Less than 7

What forms stalactites and stalagmites in underground caves?

Calcium carbonate

What is the equation for an unsaturated solution in comparing Q with Ksp?

Q < Ksp

What is the equation for a saturated solution in comparing Q with Ksp?

Q = Ksp

In which reaction will Kc equal Kp?

H2(g) + I2(g) = 2 HI(g)

For which reaction will Kp equal Ke?

C(s) + O2(g) = CO2(g)

What is the equilibrium constant expression for the reaction 2 Na(s) + 2 H2O(l) = 2 NaOH(aq) + H2(g)?

K = [H2][NaOH]²

What is the equilibrium constant expression for the reaction LiClO3(s) = LiClO(s) + O2(g)?

K = [O2]

What does it mean if Ke < Q?

The reaction will shift in the direction of reactants.

What does it mean if Ke > Q?

The reaction will shift in the direction of products.

What is the equilibrium constant for the reaction SO2(g) + NO2(g) = SO3(g) + NO(g) if the concentrations are 0.41 M SO2, 0.14 M NO2, 0.12 M SO3 and 0.14 M NO?

The reaction will shift in the direction of products.

What is the equilibrium constant for the reaction 4 CuO(s) + CH4(g) = CO2(g) + 4 Cu(s) + 2 H2O(g) if the concentrations are 0.22 M CH4, 0.70 M CO2 and 1.5 M H2O?

The reaction will shift in the direction of reactants.

What is the equilibrium constant for the reaction I2(g) + Br2(g) = 2 IBr(g) if the concentrations are 0.35 M I2, 0.31 M Br2 and 3.5 M IBr?

The system is at equilibrium.

What is the equilibrium constant for the reaction 2 SO2(g) + O2(g) = 2 SO3(g) if the equilibrium constant is 5.00 at 1300 K?

The system is at equilibrium.

What type of equilibrium occurs when the rate of the forward reaction equals the rate of the reverse reaction?

Dynamic equilibrium.

What is the result of chemical equilibrium?

Opposing reactions attaining equal rates.

What happens when K >> 1?

The forward reaction is favored and essentially goes to completion.

What happens when K << 1?

The reverse reaction is favored and the forward reaction does not proceed to a great extent.

What occurs when K = 1?

Neither the forward nor reverse reaction is strongly favored, and about the same amount of reactants and products exist at equilibrium.

What does K >> 1 imply about the reaction speed?

It implies that the reaction is very fast at producing products.

If K >> 1, which direction of the reaction is favored?

The forward reaction is favored.

If K << 1, which direction of the reaction is favored?

The reverse reaction is favored.

If K = 1, which direction of the reaction is favored?

Neither direction is favored.

How is the equilibrium constant expressed for the reaction 16 CH3Cl(g) + 8 Cl2(g) ⇌ 16 CH2Cl2(g) + 8 H2(g)?

K = [CH2Cl2]^16 [H2]^8 / [CH3Cl]^16 [Cl2]^8.

How is the equilibrium constant expressed for the reaction P4(s) + 5 O2(g) ⇌ P4010(s)?

K = [P4010] / [P4][O2]^5.

What is the value of Q in a reaction mixture containing reactants and products, each at a concentration of 1M?

Q = 1.

What is the value of Q in a reaction mixture containing only reactants?

Q = 0.

What is the value of Q in a reaction mixture containing only products?

Q = ∞.

What does it mean if Q < K?

The reverse reaction will proceed to form more reactants.

What does it mean if Q > K?

The forward reaction will proceed to form more products.

What does it mean if Q = K?

The reaction is at equilibrium.

Which statement is TRUE about dynamic equilibrium?

Dynamic equilibrium occurs when the rate of the forward reaction equals the rate of the reverse reaction.

Which of the following metals will dissolve in nitric acid but not hydrochloric acid?

Copper (Cu).

Which of the following metals will not dissolve in nitric acid or hydrochloric acid?

Silver (Ag).

Which of the following is the strongest oxidizing agent?

Br2(l).

Which of the following is the strongest reducing agent?

Mg(s).

What happens to the cell potential if the concentration of Pb2+ is increased in the galvanic cell Zn(s) | Zn2+(aq) | Pb2+(aq) | Pb(s)?

The cell potential will increase (become more positive).

Which of the following pairs of reactants will result in a spontaneous reaction at 25°C?

Pb2+(aq) + Au(s).