Answers SS - TX - Chemistry BWriting and Balancing Chemical Equations

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Which pair of substances would most likely result in the production of a gas when reacting with an acid?

litmus and methyl orange

base and salt

metal and carbonate

carbon dioxide and water

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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.

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.

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

A solution of HCl has = 0.01 M. What is the pH of this solution?Use .

–2

–1

A solution of ammonia has a pH of 11.8. What is the concentration of OH– ions in the solution?Useful formulas include , , , and .

1.58 10–12 M

6.31 10–3 M

2.20 M

158 M

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

a neutral substance

a base

an acid

both an acid and a base

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

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+

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.

Which would most likely be the pH of a highly-corrosive acid?

Look at the reaction below.Which substance is the acid in the reaction?

Mg(s)

H2(g)

MgSO4(aq)

H2SO4(aq)

The reaction below demonstrates which characteristic of a base?

the ability of bases to release sodium ions into solution

the ability of bases to release hydrogen ions into solution

the ability of a base to react with carbonate or bicarbonate

the ability of a base to react with a soluble metal salt

H2SO4 is added to a large beaker of water. How is the solution different from the original water?

The solution turns blue litmus to red.

The solution turns phenolphthalein pink.

The solution has fewer hydrogen ions.

The solution has more hydroxide ions.

Which is a characteristic of a strong base?

It turns pink phenolphthalein colorless.

It turns blue litmus paper red.

It releases H+ ions into a solution.

It removes H+ ions from solution.

What is the pH of a solution with [H+] = 1.25 10–10 M?Use .

–10.1

–9.90

7.90

9.90

What is the Arrhenius definition of an acid?

A substance that increases H3O+ concentration when it is dissolved in water.

A substance that increases OH– concentration when it is dissolved in water.

A compound that donates protons.

A compound that accepts protons.

Based on the definition of logarithms, what is the difference in hydrogen ion concentration between a substance with a pH of 2 and a substance with a pH of 3?

A substance with a pH of 2 has a 10 times higher concentration of H+ than a substance with a pH of 3.

A substance with a pH of 3 has a 10 times higher concentration of H+ than a substance with a pH of 2.

A substance with a pH of 2 has a 100 times higher concentration of H+ ions than a substance with a pH of 3.

A substance with a pH of 3 has a 100 times higher concentration of H+ ions than a substance with a pH of 2.

What is the Bronsted-Lowry definition of a base?

a compound that donates protons

a compound that accepts protons

a substance that increases hydroxide ion concentration

a substance that increases hydronium ion concentration

What is the Bronsted-Lowry definition of an acid?

a compound that donates protons

a compound that accepts protons

a substance that increases hydroxide ion concentration

a substance that increases hydronium ion concentration

Look at the reaction below.Which substance is the base in the reaction?

2H2O (l)

H2SO4 (aq)

CaSO4 (aq)

Ca(OH)2 (aq)

The main active components of bleach and many other household cleaners are

salts.

neutral.

acids.

bases.

Which statement describes the Arrhenius interpretation of acids and bases?

It has a wider range of applications than the Bronsted-Lowry interpretation.

It has a wider range of applications than the Lewis and Bronsted-Lowry interpretations.

It is used in situations that involve bases that do not produce hydroxide ions.

It is limited to situations that involve aqueous solutions or specific compounds.

Which describes an alkaline solution?

pH less than 7

pH equal to 7

basic

acidic

Consider the reaction below.HClO3 + NH3 NH4+ + ClO3–Which is a base-conjugate acid pair?

NH3 and ClO3–

NH3 and NH4+

HClO3 and NH3

HClO3 and NH4+

Consider the reaction below.HF + H2O H3O + FWhich is an acid-conjugate base pair?

HF and H3O+

HF and F

H2O and HF

H2O and F

What is the equilibrium constant of pure water at 25°C?

1014

10–14

10–7

107

Consider the reaction below.HI + H2O H3O+ + I–Which is an acid-conjugate base pair?

HI and H2O

H2O and H3O+

H3O+ and I–

HI and I–

Which of these acids occurs naturally in the body and performs important regulatory functions?

carbonic acid

acetic acid

magnesium hydroxide

sodium hydroxide

Which best describes the definition of Lewis acids and bases?

a general definition based on electron structure

a general definition based on hydrogen ion concentration

a specific definition based on a compound’s ability to accept protons

a specific definition based on a compound’s ability to donate protons

When does phenolphthalein turn pink?

in the presence of a base

in the presence of an acid

when it is in a neutral solution

when it is reacting with a metal

The pH of a solution decreases by 2.0. How does the hydronium ion concentration of the solution change?

increases to 2 times the original concentration

increases to 100 times the original concentration

decreases to of the original concentration

decreases to of the original concentration

H2CO3 is used in soft drinks. What is the name of this compound?

sulfuric acid

carbonic acid

tartaric acid

hydrochloric acid

Which is a characteristic of a Lewis base?

It behaves as the electron donor.

It behaves as the electron acceptor.

It donates a hydrogen ion to other compounds.

It increases the concentration of hydrogen ions.

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