Unit 9 Acids and Bases Review

According to the reaction CH₃NH₂ + H₂O ⇌ CH₃NH₃⁺ + OH⁻, which statement is true in the forward reaction?

• Both CH₃NH₂ and H₂O act as acids.

• Both CH₃NH₂ and H₂O act as bases.

• CH₃NH₂ acts as a base and H₂O acts as an acid.

• CH₃NH₂ acts as an acid and H₂O acts as a base.

In the same reaction above, which species is the conjugate base of the acid?

• CH₃NH₂

• H₂O

• CH₃NH₃⁺

• OH⁻

Which of the following statements is true according to Arrhenius theory?

• Acids increase OH⁻ concentration in water.

• Acids decrease H⁺ concentration in water.

• Acids increase H⁺ concentration in water.

• Acids produce water when dissolved.

A solution tastes bitter and feels slippery. Zinc metal placed in it produces no reaction. What is the most likely identity of this solution?

• HCl (aq)

• H₂SO₄ (aq)

• NaOH (aq)

• NaCl (aq)

Tags

NGSS.MS-PS1-2

Which statement is true when comparing 1.0 M HBr and 1.0 M HF?

• HBr will partially dissociate; HF will fully dissociate.

• HBr has a higher pH than HF.

• HF has a lower pH than HBr.

• HBr has a lower pH than HF.

Sulfuric acid (H₂SO₄) has a concentration of 2.7 × 10⁻³ M. What is the concentration of H⁺ ions after complete dissociation?

• 2.7 × 10⁻³ M

• 5.4 × 10⁻³ M

• 1.3 × 10⁻³ M

• 2.7 × 10¹ M

What salt forms when nitric acid reacts with strontium hydroxide in a neutralization reaction?

• Sr(NO₂)₂

• Sr(NO₃)₂

• Sr₃N₂

• H₂O

What is the correct stoichiometry setup to calculate moles of H⁺ from 21.5 mL of 1.0 M Ba(OH)₂ during titration with HCl?

• Uses molarity, volume, and mole ratios with 1 mol OH⁻ per Ba(OH)₂

• Uses molarity, volume, and 2 mol HCl per 1 mol Ba(OH)₂

• Uses a 1:1 mole ratio between Ba(OH)₂ and HCl

• Incorrectly assumes HCl is diprotic

In what case could a weak acid have a lower pH than a strong acid?

• Dilute weak acid vs concentrated strong acid

• Dilute strong acid vs concentrated weak acid

• Both acids are diluted

• Strong acid is at saturation

What is the difference in H⁺ concentration between a solution with pH 3 and pH 6?

• 10 times higher at pH 3

• 100 times higher at pH 3

• 1000 times higher at pH 3

• No difference