Question 1

Sodium fluoride is added to drinking water in some municipalities to protect teeth against cavities. The idea is to convert hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂, into more stable fluorapatite, Ca₁₀(PO₄)₆F₂. What is the molarity of a 5.0 mg/L sodium fluoride solution?

Accepted Answer

The answer of Sodium fluoride is added to drinking water...

Question 2

The drinking water standard of the World Health Organization (WHO) for arsenic is 10.0 $\mu$g/L. What is this standard in parts per billion (ppb)?

Accepted Answer

The answer of The drinking water standard of the World...

Question 3

Dinitrogen monoxide (N₂O) is produced from nitrate ions in aqueous solution by anaerobic bacteria. Which one of the following statements about this reaction is not correct? 2NO₃^-(aq) + H₂O(l) $\rightarrow$N₂O(g) + 2O₂(g) + 2OH^-(aq)

Accepted Answer

The reaction listed shows a transfer of four electrons from oxygen to nitrogen, which is not correct. The correct transfer involves two electrons being transferred from each nitrate ion, resulting in a total of four electrons being transferred in the overall reaction.

Question 4

A food chemist determined the concentration of acetic acid in a sample of apple cider vinegar. The density of the sample was 1.01 g/mL. The volume of 1.215 M NaOH required to titrate a 25.00 mL sample of the vinegar was 19.85 mL. What is (a) the molar concentration, and (b) the percent by mass of acetic acid in this vinegar? (CH₃COOH, 60.05 g/mol)

Accepted Answer

The answer of A food chemist determined the concentration of...

Question 5

Solutions of hydrochloric acid, sulfuric acid, and phosphoric acid with equal concentrations and volumes are neutralized by a solution of sodium hydroxide. If it takes 25.0 mL of the sodium hydroxide solution to neutralize the hydrochloric acid, what volume of the sodium hydroxide solution does it take to neutralize each of the other two solutions? Explain.

Accepted Answer

The answer of Solutions of hydrochloric acid, sulfuric acid, and...

Question 6

According to the label on a bottle of concentrated hydrochloric acid, the contents are 35% HCl by mass and have a density of 1.2 g/mL. What is the molarity of commercial concentrated hydrochloric acid?

Accepted Answer

The answer of According to the label on a bottle...

Question 7

A typical adult body contains about 6.0 L of blood. The hemoglobin content is about 16 g per 100.0 mL of blood. The molar mass of hemoglobin is approximately 64,000 g/mol. (a) What is the molar concentration of hemoglobin in blood, and (b) how many moles of hemoglobin are present in a typical adult?

Accepted Answer

The answer of A typical adult body contains about 6.0...

Question 8

In a spontaneous oxidation-reduction reaction between aluminum and silver ion, the aluminum(III) ion and solid silver are formed. If 0.1 mol of aluminum is consumed in this reaction, how much silver will be produced?

Accepted Answer

The answer of In a spontaneous oxidation-reduction reaction between aluminum...

Question 9

In going from the top to the bottom of the activity series below, the ease of oxidation of the metal __________, which means that __________ \[\begin{array}{l}
\text { An Activity Series for Metals in Aqueous Solution }\
\begin{array} { | l l | } 
\hline \text { Metal } & \text { Oxidation Reaction } \
\hline \text { Lithium } & \mathrm { Li } ( s ) \rightarrow \mathrm { Li } ^ { + } ( a q ) + \mathrm { e } ^ { - } \
\hline \text { Potassium } & \mathrm { K } ( s ) \rightarrow \mathrm { K } ^ { + } ( a q ) + \mathrm { e } ^ { - } \
\hline \text { Barium } & \mathrm { Baa } ( s ) \rightarrow \mathrm { Ba } ^ { 2 + } ( a q ) + 2 \mathrm { e } ^ { - } \
\hline \text { Calcium } & \mathrm { Ca } ( i ) \rightarrow \mathrm { Ca } ^ { 2 + } ( a q ) + 2 \mathrm { e } ^ { - } \
\hline \text { Sodium } & \mathrm { Na } ( s ) \rightarrow \mathrm { Na } ^ { + } ( a q ) + \mathrm { e } ^ { - } \
\hline \text { Magnesium } & \mathrm { Mg } ( s ) \rightarrow \mathrm { Mg } ^ { 2 + } ( a q ) + 2 \mathrm { e } ^ { - } \
\hline \text { Aluminum } & \mathrm { Al } ( s ) \rightarrow \mathrm { Al } ^ { 3 + } ( a g ) + 3 \mathrm { e } ^ { - } \
\hline \text { Manganese } & \mathrm { Mn } ( s ) \rightarrow \mathrm { Mn } ^ { 2 + } ( a q ) + 2 \mathrm { e } ^ { - } \
\hline \text { Zinc } & \mathrm { Zn } ( s ) \rightarrow \mathrm { Zn } ^ { 2 + } ( a q ) + 2 \mathrm { e } ^ { - } \
\hline \text { Chromium } & \mathrm { Cr } ( g ) \rightarrow \mathrm { Cr } ^ { 3 + } ( a q ) + 3 \mathrm { e } ^ { - } \
\hline
\end{array}
\end{array}\]

Accepted Answer

The activity series lists metals in order of their ability to be oxidized. As you move down the series, the ease of oxidation decreases. Therefore, magnesium, being higher in the series than zinc, can reduce zinc ions.

Question 10

The concentration of iron(II) ions in water can be determined by titration with potassium permanganate in acid solution as shown by the incomplete unbalanced reaction equation below. Identify the stoichiometric coefficient of the iron(II) ion in the balanced reaction equation. Fe²⁺(aq) + MnO₄^-$\rightarrow$ Fe³⁺(aq) + Mn²⁺(aq)

Accepted Answer

In the balanced redox reaction, 5 moles of Fe²⁺ are oxidized to Fe³⁺ for every mole of MnO₄^- reduced to Mn²⁺.

Question 11

A standard adult dose of a cough suppressant is 25.0 mL. This portion contains 50.0 mg of the active ingredient. A pediatrician suggests that this medication can be given to children over the age of 6, but only if it is diluted so the dose is 5.00 mg in 10.0 mL. How many mL of the adult medicine would you need to use to make 100.0 mL of the child-strength cough suppressant?

Accepted Answer

The answer of A standard adult dose of a cough...

Question 12

When the oxidation-reduction reaction shown here is balanced, how many electrons are transferred for each atom of copper that reacts? Ag⁺(aq) + Cu(s) $\rightarrow$Ag(s) + Cu²⁺(aq)

Accepted Answer

In order to balance the reaction, we first need to assign oxidation numbers to all the elements:

Ag: +1
S: -2
P: +1
Cu: 0
F: -1

After balancing the equation, we have:

Ag2S + Cu + H2SO4 → Ag2SO4 + CuSO4 + H2S

In this reaction, copper goes from an oxidation state of 0 to +2, meaning it has lost 2 electrons. Each atom of copper that reacts transfers 2 electrons. Therefore, the answer is B) 2.

Question 13

Milk of Magnesia is a liquid antacid. The active ingredient is magnesium hydroxide. What volume of 0.15 M stomach acid (HCl) could be neutralized by a dose of 10.0 mL containing 820 mg of the active ingredient?

Accepted Answer

The answer of Milk of Magnesia is a liquid antacid....

Question 14

Identify the solution below that will conduct electricity the best, and explain why you picked it. (a) 1.0 M NaCl, (b) 1.2 M KCl, (c) 1.0 M Na₂SO₄, (d) 0.75 M LiCl

Accepted Answer

The answer of Identify the solution below that will conduct...

Question 15

What is meant by the terms solution, solvent, and solute?

Accepted Answer

The answer of What is meant by the terms solution,...

Question 16

The half-reaction for the reduction of molecular oxygen to water is __________

Accepted Answer

The correct half-reaction for the reduction of molecular oxygen to water involves the addition of protons (H⁺) and electrons (e⁻) to oxygen, forming water.

Question 17

Sodium fluoride is added to drinking water in some municipalities to protect teeth against cavities. The target is to convert hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂, into more stable fluorapatite, Ca₁₀(PO₄)₆F₂. The U.S. Environmental Protection Agency currently restricts the concentration of fluoride in drinking water to 4 mg/L. Express this concentration in parts per million (ppm).

Accepted Answer

The answer of Sodium fluoride is added to drinking water...

Question 18

What is the difference between a strong acid and a weak acid?

Accepted Answer

The answer of What is the difference between a strong...

Question 19

Why is an aqueous solution of table salt (NaCl) a good conductor of electricity but a solution containing an equal molar concentration of table sugar (C₁₂H₂₂O₁₁) is not?

Accepted Answer

The answer of Why is an aqueous solution of table...

Question 20

Write the balanced molecular equation and the net ionic equation for the reaction of solid magnesium hydroxide with a solution of sulfuric acid.

Accepted Answer

The answer of Write the balanced molecular equation and the...

Quiz 4: Solution Chemistry: The Hydrosphere

Sodium fluoride is added to drinking water in some municipalities to protect teeth against cavities. The idea is to convert hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂, into more stable fluorapatite, Ca₁₀(PO₄)₆F₂. What is the molarity of a 5.0 mg/L sodium fluoride solution?

The drinking water standard of the World Health Organization (WHO) for arsenic is 10.0 $\mu$ g/L. What is this standard in parts per billion (ppb)?

Dinitrogen monoxide (N₂O) is produced from nitrate ions in aqueous solution by anaerobic bacteria. Which one of the following statements about this reaction is not correct? 2NO₃^-(aq) + H₂O(l) $\rightarrow$ N₂O(g) + 2O₂(g) + 2OH^-(aq)

According to the label on a bottle of concentrated hydrochloric acid, the contents are 35% HCl by mass and have a density of 1.2 g/mL. What is the molarity of commercial concentrated hydrochloric acid?

A typical adult body contains about 6.0 L of blood. The hemoglobin content is about 16 g per 100.0 mL of blood. The molar mass of hemoglobin is approximately 64,000 g/mol. (a) What is the molar concentration of hemoglobin in blood, and (b) how many moles of hemoglobin are present in a typical adult?

In a spontaneous oxidation-reduction reaction between aluminum and silver ion, the aluminum(III) ion and solid silver are formed. If 0.1 mol of aluminum is consumed in this reaction, how much silver will be produced?

When the oxidation-reduction reaction shown here is balanced, how many electrons are transferred for each atom of copper that reacts? Ag⁺(aq) + Cu(s) $\rightarrow$ Ag(s) + Cu²⁺(aq)

Milk of Magnesia is a liquid antacid. The active ingredient is magnesium hydroxide. What volume of 0.15 M stomach acid (HCl) could be neutralized by a dose of 10.0 mL containing 820 mg of the active ingredient?

Identify the solution below that will conduct electricity the best, and explain why you picked it. (a) 1.0 M NaCl, (b) 1.2 M KCl, (c) 1.0 M Na₂SO₄, (d) 0.75 M LiCl

What is meant by the terms solution, solvent, and solute?

The half-reaction for the reduction of molecular oxygen to water is __________

What is the difference between a strong acid and a weak acid?

Why is an aqueous solution of table salt (NaCl) a good conductor of electricity but a solution containing an equal molar concentration of table sugar (C₁₂H₂₂O₁₁) is not?

Write the balanced molecular equation and the net ionic equation for the reaction of solid magnesium hydroxide with a solution of sulfuric acid.

Quiz 4: Solution Chemistry: The Hydrosphere

Sodium fluoride is added to drinking water in some municipalities to protect teeth against cavities. The idea is to convert hydroxyapatite, Ca10(PO4)6(OH)2, into more stable fluorapatite, Ca10(PO4)6F2. What is the molarity of a 5.0 mg/L sodium fluoride solution?

The drinking water standard of the World Health Organization (WHO) for arsenic is 10.0 μ\muμ g/L. What is this standard in parts per billion (ppb)?

Dinitrogen monoxide (N2O) is produced from nitrate ions in aqueous solution by anaerobic bacteria. Which one of the following statements about this reaction is not correct? 2NO3-(aq) + H2O(l) →\rightarrow→ N2O(g) + 2O2(g) + 2OH-(aq)

According to the label on a bottle of concentrated hydrochloric acid, the contents are 35% HCl by mass and have a density of 1.2 g/mL. What is the molarity of commercial concentrated hydrochloric acid?

In a spontaneous oxidation-reduction reaction between aluminum and silver ion, the aluminum(III) ion and solid silver are formed. If 0.1 mol of aluminum is consumed in this reaction, how much silver will be produced?

When the oxidation-reduction reaction shown here is balanced, how many electrons are transferred for each atom of copper that reacts? Ag+(aq) + Cu(s) →\rightarrow→ Ag(s) + Cu2+(aq)

Milk of Magnesia is a liquid antacid. The active ingredient is magnesium hydroxide. What volume of 0.15 M stomach acid (HCl) could be neutralized by a dose of 10.0 mL containing 820 mg of the active ingredient?

Identify the solution below that will conduct electricity the best, and explain why you picked it. (a) 1.0 M NaCl, (b) 1.2 M KCl, (c) 1.0 M Na2SO4, (d) 0.75 M LiCl

What is meant by the terms solution, solvent, and solute?

The half-reaction for the reduction of molecular oxygen to water is __________

What is the difference between a strong acid and a weak acid?

Why is an aqueous solution of table salt (NaCl) a good conductor of electricity but a solution containing an equal molar concentration of table sugar (C12H22O11) is not?

Write the balanced molecular equation and the net ionic equation for the reaction of solid magnesium hydroxide with a solution of sulfuric acid.

Sodium fluoride is added to drinking water in some municipalities to protect teeth against cavities. The idea is to convert hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂, into more stable fluorapatite, Ca₁₀(PO₄)₆F₂. What is the molarity of a 5.0 mg/L sodium fluoride solution?

The drinking water standard of the World Health Organization (WHO) for arsenic is 10.0 $\mu$ g/L. What is this standard in parts per billion (ppb)?

Dinitrogen monoxide (N₂O) is produced from nitrate ions in aqueous solution by anaerobic bacteria. Which one of the following statements about this reaction is not correct? 2NO₃^-(aq) + H₂O(l) $\rightarrow$ N₂O(g) + 2O₂(g) + 2OH^-(aq)

When the oxidation-reduction reaction shown here is balanced, how many electrons are transferred for each atom of copper that reacts? Ag⁺(aq) + Cu(s) $\rightarrow$ Ag(s) + Cu²⁺(aq)

Identify the solution below that will conduct electricity the best, and explain why you picked it. (a) 1.0 M NaCl, (b) 1.2 M KCl, (c) 1.0 M Na₂SO₄, (d) 0.75 M LiCl

Why is an aqueous solution of table salt (NaCl) a good conductor of electricity but a solution containing an equal molar concentration of table sugar (C₁₂H₂₂O₁₁) is not?