Unit Test on Acid and Bases

A salt is best described as a compound that is formed from the reaction between

• an acid and a base.

• a strong acid and a weak acid.

• a strong base and a weak base.

• an acid and water.

Which of these correctly defines the pOH of a solution?

• the log of the hydronium ion concentration

• the negative log of the hydronium ion concentration

• the log of the hydroxide ion concentration

• the negative log of the hydroxide ion concentration

Which description correctly characterizes the acidity or basicity of a solution?

• The higher the pH is, the more the hydroxide ion concentration decreases and the more acidic the solution becomes.

• The higher the pH is, the more the hydroxide ion concentration increases and the more basic the solution becomes.

• The lower the pH is, the more the hydronium ion concentration decreases and the more acidic the solution becomes.

• The lower the pH is, the more the hydronium ion concentration increases and the more basic the solution becomes.

Consider the reaction below.

NH₄⁺ + H₂O NH₃ + H₃O⁺

Which is an acid-conjugate base pair?

• NH₄⁺ and NH₃

• NH₄⁺ and H₃O⁺

• H₂O and NH₃

• H₂O and H₃O⁺

What is the definition of a Lewis base?

• a substance that donates a proton

• a substance that donates electrons to form a covalent bond

• a substance that accepts electrons to form a covalent bond

• a substance that when dissolved in water increases hydrogen ion concentration

Which of the following substances is an Arrhenius acid?

• BF₃

• HCN

• NH₃

• Mg(OH)₂

Lewis acids and bases are most closely associated with which process?

• proton transfer

• electron transfer

• the formation of aqueous ions

• the formation of a conjugate acid or base

What type of substance reacts with limestone (CaCO₃) and produces carbon dioxide gas?

• a neutral substance

• base

• an acid

• both an acid and a base

Tags

NGSS.MS-PS1-2

Soaps feel slippery on our hands because they dissolve the oil on our skin, decreasing friction.This is because soap contains

• a neutral molecule.

• a salt molecule.

• an acid.

• a base.

An unknown substance turns blue litmus paper to red. Which additional test could be used to confirm the substance’s identity?

• It should turn phenolphthalein from colorless to pink because it is a base.

• It should turn phenolphthalein from pink to colorless because it is a base.

• It should turn methyl orange to orange because it is an acid.

• It should turn methyl orange to red because it is an acid.

Tags

NGSS.MS-PS1-2