Question 1

What is the H₃O⁺ concentration in a solution formed by dissolving 63 g of HNO₃ in 2.0 liters of water? [molar mass of HNO₃ = 63 g/mol]

Accepted Answer

First, we need to calculate the number of moles of HNO₃: moles = mass/molar mass = 63 g/63 g/mol = 1 mol Next, we need to calculate the concentration: concentration = moles/volume = 1 mol/2.0 L = 0.50 M Therefore, the concentration of H₃O⁺ in the solution is 0.50 M, which corresponds to choice B.

Question 2

Which base listed below would be the strongest given the corresponding acid ionization constants for their conjugate acids?

Accepted Answer

The strength of a base is inversely related to the strength of its conjugate acid. The higher the Ka value of the conjugate acid, the weaker the base. The conjugate acid with the lowest Ka value (4.2×10^-13) corresponds to the strongest base, which is option A.

Question 3

Consider the following unfinished table of weak acids with their corresponding P K _a values and K _a values. Weak Acid p K _a K _a HNO₂ 3.35 -- HF -- 6.8×10^{- 4} HCN 9.31 -- Arrange these three acids in order of increasing acid strength .

Accepted Answer

To determine relative acid strength, we compare the values of pKs or Ka. The lower the pKs or the higher the Ka, the stronger the acid. HCN has the highest pKs, making it the weakest acid. HF has a lower pKs than HNO₂, making it a stronger acid. Therefore, the correct order of increasing acid strength is HCN < HNO₂ < HF, or choice D.

Question 4

After completing the following unfinished Base Ionization table, what is the order of increasing base strength ? Base K _b p K _b Bicarbonate ion, HCO₃^- 2.2×10^{- 8} Pyridine, C₅H₅N 8.77 Acetate ion, CH₃COO^- 5.7×10^{- 10}

Accepted Answer

The answer of After completing the following unfinished Base Ionization...

Question 5

Milk of magnesia is essentially a saturated solution of Mg(OH)₂ ( K _sp = 8.9×10^{- 12}). What is the pH of a saturated Mg(OH)₂ solution?

Accepted Answer

The solubility product (Ksp) of Mg(OH)2 is used to calculate the concentration of OH- ions in solution. From Ksp = [Mg2+][OH-]^2, we find [OH-] = 2.82 x 10^-4 M. The pOH is -log[OH-] = 3.55, and pH = 14 - pOH = 10.45, which is closest to 10.42.

Question 6

What is the pH of 2.7 M Ba(OH)₂?

Accepted Answer

The answer of What is the pH of 2.7 M...

Question 7

50 mL of 0.50 M NaOH is added to enough water to make 1.0 liter of solution. Calculate the pH.

Accepted Answer

The concentration of NaOH after dilution is calculated using the formula $C_1V_1 = C_2V_2$, where $C_1$ and $V_1$ are the initial concentration and volume, and $C_2$ and $V_2$ are the final concentration and volume, respectively. Substituting the given values, $0.50 \, \text{M} \times 0.050 \, \text{L} = C_2 \times 1.0 \, \text{L}$, we find $C_2 = 0.025 \, \text{M}$. Since NaOH is a strong base, it fully dissociates in water, and the concentration of OH- ions is also $0.025 \, \text{M}$. The pOH is calculated using the formula $pOH = -\log[OH^-]$, which gives $pOH = -\log(0.025) \approx 1.6$. The pH can then be found using the relation $pH + pOH = 14$, which gives $pH = 14 - 1.6 = 12.4$.

Question 8

What is the pH of a solution prepared by dissolving 0.28 grams of KOH in 250 mL of solution?
(molar mass KOH = 56.11 g/mol)

Accepted Answer

First, calculate the moles of KOH: 0.28 g / 56.11 g/mol = 0.00499 mol. Since KOH is a strong base, it dissociates completely in water, providing 0.00499 mol of OH- ions in 0.250 L solution. The concentration of OH- ions is 0.00499 mol / 0.250 L = 0.01996 M. The pOH is calculated using the formula pOH = -log[OH-], which gives pOH = -log(0.01996) ≈ 1.70. Since pH + pOH = 14 for aqueous solutions, the pH is 14 - 1.70 = 12.30.

Question 9

A weak acid

Accepted Answer

A weak acid does not fully dissociate in water, meaning it only partially ionizes into its conjugate base and H+ ions. This makes it less reactive with bases, glass, and skin compared to strong acids. However, it can still pose a disposal problem if not handled properly.

Question 10

Which anionic base listed below would be the strongest given the corresponding acid ionization constants for their conjugate acids?

Accepted Answer

The strength of an anionic base is inversely related to the strength of its conjugate acid. The lower the acid ionization constant (Ka) of the conjugate acid, the weaker the acid, and thus the stronger its conjugate base. Among the given options, acetic acid (CH3COOH) has the lowest Ka value (1.8×10^-5), making its conjugate base (CH3COO-) the strongest base listed.

Question 11

A 0.010 M solution of the strong acid HNO₃ is prepared. Which of the following statements is false ?

Accepted Answer

The acid is completely ionized in solution, meaning the equilibrium concentration of HNO₃ is nearly 0, not 0.010 M.

Question 12

What is the pH of a solution prepared by dissolving 0.13 grams of HI (molar mass HI = 127.9 g/mol) in 300 mL of solution?

Accepted Answer

Step 1: Calculate the number of moles of HI:
0.13 g HI x (1 mol HI/127.9 g HI) = 0.00102 mol HI

Step 2: Calculate the molarity of the solution:
Molarity = (moles of solute)/(volume of solution in L)
Volume of solution = 300 mL = 0.3 L
Molarity = 0.00102 mol/0.3 L = 0.0034 M

Step 3: HI is a strong acid, so it will completely dissociate in water:
HI → H+ + I-

Step 4: Calculate the concentration of H+ ions:
[H+] = 0.0034 M

Step 5: Calculate the pH:
pH = -log[H+]
pH = -log(0.0034)
pH = 2.47

Therefore, the answer is B.

Question 13

Rank the following three acids in terms of acid strength given the following information: Acid K _a p K _a HF 6.9×10^{- 4} -- CH₃COOH -- 4.74 HNO₂ 4.5×10^{- 4}

Accepted Answer

The strength of an acid is inversely proportional to its pKa value. Among the given acids, HNO₂ has the lowest pKa value (4.5), indicating it is the strongest acid. CH₃COOH has a pKa of 4.74, making it weaker than HNO₂. HF has the highest pKa value (6.9), making it the weakest acid among the three. Thus, the correct order of acid strength is HNO₂ > CH₃COOH > HF. This order is represented by choice B.

Question 14

According to the definition of pH, what would be the pH of a 10 M solution of HCl?

Accepted Answer

The pH of a solution is calculated using the formula pH = -log[H+], where [H+] is the concentration of hydrogen ions in moles per liter. For a 10 M solution of HCl, which fully dissociates in water, [H+] = 10 M. Thus, pH = -log(10) = -1.

Question 15

What is the pH of a 1.6 M aqueous solution of Sr(OH)₂?

Accepted Answer

The answer of What is the pH of a 1.6...

Question 16

Consider the following unfinished table of weak acids with their corresponding p K _a values and K _a values. Weak Acid p K _a K _a Benzoic acid 4.20 -- Lactic acid -- 1.4×10^{- 4} Chlorous acid 1.96 -- Arrange these three acids in order of increasing acid strength .

Accepted Answer

The strength of an acid is inversely related to its pKa value and directly related to its Ka value. Lower pKa or higher Ka indicates a stronger acid. Given pKa values: Benzoic acid (4.20) > Chlorous acid (1.96). Lactic acid's Ka is given, and converting it to pKa using the relation pKa = -log(Ka) gives a pKa value greater than 4.20 but less than the pKa of Chlorous acid, placing Lactic acid between Benzoic and Chlorous acid in terms of strength.

Question 17

Calculate the pOH of a solution made by dissolving 2.0 grams of NaOH (molar mass = 40.0 g/mol) in water and diluting tO₅ 00 mL.

Accepted Answer

The molarity of NaOH is calculated by dividing the mass of NaOH by its molar mass and then by the volume of the solution in liters. For 2.0 grams of NaOH in 1.0 L (1000 mL) of solution, the molarity is $ \frac{2.0 \, \text{g}}{40.0 \, \text{g/mol}} \times \frac{1}{1.0 \, \text{L}} = 0.05 \, \text{M} $. Since NaOH is a strong base, it completely dissociates in water, so the concentration of OH- ions is also 0.05 M. The pOH is calculated using the formula $ \text{pOH} = -\log[OH^-] $, which gives $ \text{pOH} = -\log(0.05) = 1.00 $.

Question 18

Which acid listed below would be the strongest given the corresponding base ionization constants for their conjugate bases?

Accepted Answer

The strength of an acid is inversely related to the base ionization constant (K_b) of its conjugate base. The smaller the K_b, the stronger the acid. HClO₂ has the smallest K_b value (9.1×10^{- 13}), making it the strongest acid among the options.

Question 19

After completing the following unfinished table, what is the order of increasing base strength ? Base K _b p K _b Fluoride ion, F^- 1.5×10^{- 11} Ammonia, NH₃ 4.75 Acetate ion, CH₃COO^- 5.7×10^{- 10}

Accepted Answer

The base strength increases with increasing Kb and decreasing pKb. Fluoride ion has the lowest Kb, followed by acetate ion, and ammonia has the highest Kb, making it the strongest base.

Question 20

After completing the following unfinished table, what is the order of increasing acid strength ? Acid K _a p K _a Propanoic acid 1.3×10^{- 5} Chlorous acid 1.96 Benzoic acid 6.3×10^{- 5}

Accepted Answer

The strength of an acid is determined by its Ka value; the larger the Ka, the stronger the acid. Chlorous acid has the highest Ka (lowest pKa), followed by benzoic acid, and then propanoic acid.

Quiz 15: Solutions of Acids and Bases

What is the H₃O⁺ concentration in a solution formed by dissolving 63 g of HNO₃ in 2.0 liters of water? [molar mass of HNO₃ = 63 g/mol]

Which base listed below would be the strongest given the corresponding acid ionization constants for their conjugate acids?

Consider the following unfinished table of weak acids with their corresponding P K _a values and K _a values. Weak Acid p K _a K _a HNO₂ 3.35 -- HF -- 6.8×10^{- 4} HCN 9.31 -- Arrange these three acids in order of increasing acid strength .

After completing the following unfinished Base Ionization table, what is the order of increasing base strength ? Base K _b p K _b Bicarbonate ion, HCO₃^- 2.2×10^{- 8} Pyridine, C₅H₅N 8.77 Acetate ion, CH₃COO^- 5.7×10^{- 10}

Milk of magnesia is essentially a saturated solution of Mg(OH) ₂ ( K _sp = 8.9×10^{- 12}) . What is the pH of a saturated Mg(OH) ₂ solution?

What is the pH of 2.7 M Ba(OH) ₂?

50 mL of 0.50 M NaOH is added to enough water to make 1.0 liter of solution. Calculate the pH.

What is the pH of a solution prepared by dissolving 0.28 grams of KOH in 250 mL of solution? (molar mass KOH = 56.11 g/mol)

A weak acid

Which anionic base listed below would be the strongest given the corresponding acid ionization constants for their conjugate acids?

A 0.010 M solution of the strong acid HNO₃ is prepared. Which of the following statements is false ?

What is the pH of a solution prepared by dissolving 0.13 grams of HI (molar mass HI = 127.9 g/mol) in 300 mL of solution?

Rank the following three acids in terms of acid strength given the following information: Acid K _a p K _a HF 6.9×10^{- 4} -- CH₃COOH -- 4.74 HNO₂ 4.5×10^{- 4}

According to the definition of pH, what would be the pH of a 10 M solution of HCl?

What is the pH of a 1.6 M aqueous solution of Sr(OH) ₂?

Consider the following unfinished table of weak acids with their corresponding p K _a values and K _a values. Weak Acid p K _a K _a Benzoic acid 4.20 -- Lactic acid -- 1.4×10^{- 4} Chlorous acid 1.96 -- Arrange these three acids in order of increasing acid strength .

Calculate the pOH of a solution made by dissolving 2.0 grams of NaOH (molar mass = 40.0 g/mol) in water and diluting tO₅ 00 mL.

Which acid listed below would be the strongest given the corresponding base ionization constants for their conjugate bases?

After completing the following unfinished table, what is the order of increasing base strength ? Base K _b p K _b Fluoride ion, F^- 1.5×10^{- 11} Ammonia, NH₃ 4.75 Acetate ion, CH₃COO^- 5.7×10^{- 10}

After completing the following unfinished table, what is the order of increasing acid strength ? Acid K _a p K _a Propanoic acid 1.3×10^{- 5} Chlorous acid 1.96 Benzoic acid 6.3×10^{- 5}

Quiz 15: Solutions of Acids and Bases

What is the H3O+ concentration in a solution formed by dissolving 63 g of HNO3 in 2.0 liters of water? [molar mass of HNO3 = 63 g/mol]

Which base listed below would be the strongest given the corresponding acid ionization constants for their conjugate acids?

Consider the following unfinished table of weak acids with their corresponding P K a values and K a values. Weak Acid p K a K a HNO2 3.35 -- HF -- 6.8×10 - 4 HCN 9.31 -- Arrange these three acids in order of increasing acid strength .

After completing the following unfinished Base Ionization table, what is the order of increasing base strength ? Base K b p K b Bicarbonate ion, HCO3 - 2.2×10 - 8 Pyridine, C5H5N 8.77 Acetate ion, CH3COO - 5.7×10 - 10

Milk of magnesia is essentially a saturated solution of Mg(OH) 2 ( K sp = 8.9×10 - 12) . What is the pH of a saturated Mg(OH) 2 solution?

What is the pH of 2.7 M Ba(OH) 2?

50 mL of 0.50 M NaOH is added to enough water to make 1.0 liter of solution. Calculate the pH.

What is the pH of a solution prepared by dissolving 0.28 grams of KOH in 250 mL of solution? (molar mass KOH = 56.11 g/mol)

A weak acid

Which anionic base listed below would be the strongest given the corresponding acid ionization constants for their conjugate acids?

A 0.010 M solution of the strong acid HNO3 is prepared. Which of the following statements is false ?

What is the pH of a solution prepared by dissolving 0.13 grams of HI (molar mass HI = 127.9 g/mol) in 300 mL of solution?

Rank the following three acids in terms of acid strength given the following information: Acid K a p K a HF 6.9×10 - 4 -- CH3COOH -- 4.74 HNO2 4.5×10 - 4

According to the definition of pH, what would be the pH of a 10 M solution of HCl?

What is the pH of a 1.6 M aqueous solution of Sr(OH) 2?

Consider the following unfinished table of weak acids with their corresponding p K a values and K a values. Weak Acid p K a K a Benzoic acid 4.20 -- Lactic acid -- 1.4×10 - 4 Chlorous acid 1.96 -- Arrange these three acids in order of increasing acid strength .

Calculate the pOH of a solution made by dissolving 2.0 grams of NaOH (molar mass = 40.0 g/mol) in water and diluting tO5 00 mL.

Which acid listed below would be the strongest given the corresponding base ionization constants for their conjugate bases?

After completing the following unfinished table, what is the order of increasing base strength ? Base K b p K b Fluoride ion, F - 1.5×10 - 11 Ammonia, NH3 4.75 Acetate ion, CH3COO - 5.7×10 - 10

After completing the following unfinished table, what is the order of increasing acid strength ? Acid K a p K a Propanoic acid 1.3×10 - 5 Chlorous acid 1.96 Benzoic acid 6.3×10 - 5

What is the H₃O⁺ concentration in a solution formed by dissolving 63 g of HNO₃ in 2.0 liters of water? [molar mass of HNO₃ = 63 g/mol]

Consider the following unfinished table of weak acids with their corresponding P K _a values and K _a values. Weak Acid p K _a K _a HNO₂ 3.35 -- HF -- 6.8×10^{- 4} HCN 9.31 -- Arrange these three acids in order of increasing acid strength .

After completing the following unfinished Base Ionization table, what is the order of increasing base strength ? Base K _b p K _b Bicarbonate ion, HCO₃^- 2.2×10^{- 8} Pyridine, C₅H₅N 8.77 Acetate ion, CH₃COO^- 5.7×10^{- 10}

Milk of magnesia is essentially a saturated solution of Mg(OH) ₂ ( K _sp = 8.9×10^{- 12}) . What is the pH of a saturated Mg(OH) ₂ solution?

What is the pH of 2.7 M Ba(OH) ₂?

A 0.010 M solution of the strong acid HNO₃ is prepared. Which of the following statements is false ?

Rank the following three acids in terms of acid strength given the following information: Acid K _a p K _a HF 6.9×10^{- 4} -- CH₃COOH -- 4.74 HNO₂ 4.5×10^{- 4}

What is the pH of a 1.6 M aqueous solution of Sr(OH) ₂?

Consider the following unfinished table of weak acids with their corresponding p K _a values and K _a values. Weak Acid p K _a K _a Benzoic acid 4.20 -- Lactic acid -- 1.4×10^{- 4} Chlorous acid 1.96 -- Arrange these three acids in order of increasing acid strength .

Calculate the pOH of a solution made by dissolving 2.0 grams of NaOH (molar mass = 40.0 g/mol) in water and diluting tO₅ 00 mL.

After completing the following unfinished table, what is the order of increasing base strength ? Base K _b p K _b Fluoride ion, F^- 1.5×10^{- 11} Ammonia, NH₃ 4.75 Acetate ion, CH₃COO^- 5.7×10^{- 10}

After completing the following unfinished table, what is the order of increasing acid strength ? Acid K _a p K _a Propanoic acid 1.3×10^{- 5} Chlorous acid 1.96 Benzoic acid 6.3×10^{- 5}