Question 1

Two phosphoric acid molecules can combine to make pyrophosphoric acid and another molecule as shown here. The pyrophosphoric acid molecule is a phosphoester and is a structural element in the ADP/ATP metabolic energy system. What molecule is represented by the question mark in the structural reaction equation below?

Accepted Answer

The structural formula for pyrophosphoric acid is HS1U1P2S1U1P2S1U1OH. When two phosphoric acid molecules combine, they lose a water molecule and form a phosphoanhydride bond between the two phosphate groups, resulting in the formation of pyrophosphoric acid (HS1U1P2S1U1P2S1U1OH) and a molecule containing a phosphate group. The only answer choice with a phosphate group is C, which represents the molecule H2PO4-.

Question 2

Hydroxyapatite, [Ca₅(PO₄)₃(OH)], the major component of tooth enamel, is attacked and decomposed by acids more readily than fluorapatite, [Ca₅(PO₄)₃F]. Which one of the following reactions is analogous to the reaction of hydroxyapatite?

Accepted Answer

The reaction of hydroxyapatite with acid involves the neutralization of hydroxide ions (OH⁻) by hydrogen ions (H⁺), similar to the reaction of Ca(OH)₂ with H⁺ to form water.

Question 3

If one regular antacid tablet contains 500 mg of solid CaCO₃ (100 g/mol), how many mL of 1.0 M stomach acid (HCl) could it neutralize?

Accepted Answer

The reaction between CaCO3 and HCl is CaCO3 + 2HCl → CaCl2 + CO2 + H2O. Since one mole of CaCO3 reacts with two moles of HCl, and one tablet contains 5 moles of CaCO3 (500 mg / 100 g/mol = 5 mmol = 0.005 mol), it can neutralize 0.01 moles of HCl. Since the concentration of HCl is 1.0 M, which means 1 mole per liter, 0.01 moles of HCl is contained in 10 mL of solution (0.01 moles / 1.0 M = 0.01 L = 10 mL).

Question 4

If 1.0 L of 1.0 M HCl spilled and needed to be neutralized, how many grams of the solid sodium carbonate (Na₂CO₃, 106 g/mol) would be required?

Accepted Answer

The neutralization reaction between HCl and Na2CO3 can be represented as: 2 HCl + Na2CO3 -> 2 NaCl + H2O + CO2. This shows that 2 moles of HCl react with 1 mole of Na2CO3. Since 1.0 L of 1.0 M HCl contains 1.0 mole of HCl, 0.5 moles of Na2CO3 are needed for neutralization. The molar mass of Na2CO3 is 106 g/mol, so 0.5 moles would weigh 53 g (0.5 * 106 g/mol = 53 g).

Question 5

What would be the products in the overall ionic equation for the following reaction? 2HBr(aq) + 2KOH(aq) $\rightarrow$ products I. K⁺(aq) and Br ^-(aq); II. KH(aq); III. H₂O(l ); IV. KBr(s); V. BrOH(aq); VI. KBr(aq)

Accepted Answer

The answer of What would be the products in the...

Question 6

Which picture best represents an atomic-level view of hydrochloric acid, which is a strong acid, in aqueous solution (water molecules not shown)?

Accepted Answer

The answer of Which picture best represents an atomic-level view...

Question 7

Calcium hydroxide is slightly soluble in water. About 1 gram will dissolve in 1 liter. What are the spectator ions in the reaction of such a dilute solution of calcium hydroxide with hydrochloric acid?

Accepted Answer

In the reaction between calcium hydroxide and hydrochloric acid, the calcium ions (Ca²⁺) and chloride ions (Cl^-) do not participate in the formation of water and remain unchanged in the solution, making them spectator ions.

Question 8

Which one of the following is not a polyprotic acid?

Accepted Answer

Acetic acid (CH3COOH) is not a polyprotic acid because it can donate only one proton (H+ ion), unlike the others listed, which can donate more than one proton.

Question 9

Identify the base in the following acid-base reaction. PbCO₃(s) + H₂SO₄(aq) $\rightarrow$ PbSO₄(s) + CO₂(g) + H₂O(l)

Accepted Answer

The base in the reaction is CO₃²^- because it accepts H⁺ ions from H₂SO₄ to form H₂O.

Question 10

Hartmann's solution is used in intravenous therapy to replace lost body fluid and mineral salts. Hartmann's solution contains 5.00 mM potassium chloride, 2.00 mM calcium chloride, and
102 mM sodium chloride. What is the total chloride ion concentration in Hartmann's solution?

Accepted Answer

The answer of Hartmann's solution is used in intravenous therapy...

Question 11

Which one of the following statements regarding a strong acid is not correct?

Accepted Answer

The statement "Acids are only strong at a high concentration" is not correct. The strength of an acid is a measure of the degree to which it ionizes in water, regardless of its concentration. A strong acid will ionize completely in water whether its concentration is high or low. However, the concentration of an acid can affect its pH and acidity. Higher concentrations of acid will result in a lower pH and stronger acidity.

Question 12

What is the molar concentration of sodium in a 200.0 mL solution prepared from 1.223 g of sodium phosphate (Na₃PO₄, 163.9 g/mol), which is a cleaning agent, food additive, and stain remover?

Accepted Answer

The answer of What is the molar concentration of sodium...

Question 13

Which one of the following statements regarding a weak acid is not correct?

Accepted Answer

The statement "All acids are weak at low concentrations" is not correct. Strong acids are still strong acids even at low concentrations, while weak acids remain weak acids at both low and high concentrations.

Question 14

Identify the acid in the following acid-base reaction. PbCO₃(s) + H₂SO₄(aq) $\rightarrow$ PbSO₄(s) + CO₂(g) + H₂O(l )

Accepted Answer

In the given reaction, the acid is H₂SO₄(aq) which reacts with PbCO₃(s) to form PbSO₄(s), CO₂(g), and H₂O(l).

Question 15

A cross section of a Mad-Dawg gumball shows an outer layer of citric acid and malonic acid, beneath that a layer of food coloring, sugar, and flavoring, beneath that a layer of sodium bicarbonate (NaHCO₃), and finally in the middle-gum! A 12-year-old puts one in his mouth and immediately puckers, smiles, and then foams at the mouth before chewing. Where did the foam come from?

Accepted Answer

When citric acid and malonic acid react with sodium bicarbonate, it produces an unstable carbonic acid, which then breaks down into water and carbon dioxide gas. The release of carbon dioxide gas creates the foam.

Question 16

Which one of the following reaction equations is the net ionic equation for the reaction of hydrochloric acid with lithium hydroxide? All species are in aqueous solution.

Accepted Answer

The net ionic equation for the reaction between hydrochloric acid and lithium hydroxide is the formation of water from hydrogen ions and hydroxide ions, as the other ions are spectator ions.

Question 17

Which one of the following reaction equations is the molecular equation for the reaction of hydrochloric acid with sodium hydroxide? All species are in aqueous solution.

Accepted Answer

The answer of Which one of the following reaction equations...

Question 18

Identify a spectator ion in the following acid-base reaction. Ca(CO₃)(s) + 2HCl(aq) $\rightarrow$CaCl₂(aq) + 2H₂O(l ) + CO₂(g)

Accepted Answer

In the reaction, Ca(CO₃) and HCl react to form CaCl₂ and CO₂(g). The only spectator ion present in the reaction is Cl^- since it does not participate in the reaction and remains unchanged on both sides. Therefore, the correct answer is C) Cl^-.

Question 19

In its reaction with water, ammonia (NH₃) __________

Accepted Answer

Ammonia acts as a base in its reaction with water, as it accepts a proton (H+) from water to form ammonium ion (NH4+) and hydroxide ion (OH-).

Question 20

Chalk contains calcium carbonate. What would be the best solution for cleaning a sidewalk that a preschool class covered with smiling suns, flowers, birds, rainbows, and houses using sidewalk chalk?

Accepted Answer

The answer of Chalk contains calcium carbonate. What would be...

Quiz 4: Solution Chemistry: The Hydrosphere

Hydroxyapatite, [Ca₅(PO₄) ₃(OH) ], the major component of tooth enamel, is attacked and decomposed by acids more readily than fluorapatite, [Ca₅(PO₄) ₃F]. Which one of the following reactions is analogous to the reaction of hydroxyapatite?

If one regular antacid tablet contains 500 mg of solid CaCO₃ (100 g/mol) , how many mL of 1.0 M stomach acid (HCl) could it neutralize?

If 1.0 L of 1.0 M HCl spilled and needed to be neutralized, how many grams of the solid sodium carbonate (Na₂CO₃, 106 g/mol) would be required?

What would be the products in the overall ionic equation for the following reaction? 2HBr(aq) + 2KOH(aq) $\rightarrow$ products I. K⁺(aq) and Br ^-(aq) ; II. KH(aq) ; III. H₂O(l ) ; IV. KBr(s) ; V. BrOH(aq) ; VI. KBr(aq)

Which picture best represents an atomic-level view of hydrochloric acid, which is a strong acid, in aqueous solution (water molecules not shown) ?

Calcium hydroxide is slightly soluble in water. About 1 gram will dissolve in 1 liter. What are the spectator ions in the reaction of such a dilute solution of calcium hydroxide with hydrochloric acid?

Which one of the following is not a polyprotic acid?

Identify the base in the following acid-base reaction. PbCO₃(s) + H₂SO₄(aq) $\rightarrow$ PbSO₄(s) + CO₂(g) + H₂O(l)

Hartmann's solution is used in intravenous therapy to replace lost body fluid and mineral salts. Hartmann's solution contains 5.00 mM potassium chloride, 2.00 mM calcium chloride, and 102 mM sodium chloride. What is the total chloride ion concentration in Hartmann's solution?

Which one of the following statements regarding a strong acid is not correct?

What is the molar concentration of sodium in a 200.0 mL solution prepared from 1.223 g of sodium phosphate (Na₃PO₄, 163.9 g/mol) , which is a cleaning agent, food additive, and stain remover?

Which one of the following statements regarding a weak acid is not correct?

Identify the acid in the following acid-base reaction. PbCO₃(s) + H₂SO₄(aq) $\rightarrow$ PbSO₄(s) + CO₂(g) + H₂O(l )

Which one of the following reaction equations is the net ionic equation for the reaction of hydrochloric acid with lithium hydroxide? All species are in aqueous solution.

Which one of the following reaction equations is the molecular equation for the reaction of hydrochloric acid with sodium hydroxide? All species are in aqueous solution.

Identify a spectator ion in the following acid-base reaction. Ca(CO₃) (s) + 2HCl(aq) $\rightarrow$ CaCl₂(aq) + 2H₂O(l ) + CO₂(g)

In its reaction with water, ammonia (NH₃) __________

Chalk contains calcium carbonate. What would be the best solution for cleaning a sidewalk that a preschool class covered with smiling suns, flowers, birds, rainbows, and houses using sidewalk chalk?

Quiz 4: Solution Chemistry: The Hydrosphere

Hydroxyapatite, [Ca5(PO4) 3(OH) ], the major component of tooth enamel, is attacked and decomposed by acids more readily than fluorapatite, [Ca5(PO4) 3F]. Which one of the following reactions is analogous to the reaction of hydroxyapatite?

If one regular antacid tablet contains 500 mg of solid CaCO3 (100 g/mol) , how many mL of 1.0 M stomach acid (HCl) could it neutralize?

If 1.0 L of 1.0 M HCl spilled and needed to be neutralized, how many grams of the solid sodium carbonate (Na2CO3, 106 g/mol) would be required?

What would be the products in the overall ionic equation for the following reaction? 2HBr(aq) + 2KOH(aq) →\rightarrow→ products I. K+(aq) and Br -(aq) ; II. KH(aq) ; III. H2O(l ) ; IV. KBr(s) ; V. BrOH(aq) ; VI. KBr(aq)

Which picture best represents an atomic-level view of hydrochloric acid, which is a strong acid, in aqueous solution (water molecules not shown) ?

Calcium hydroxide is slightly soluble in water. About 1 gram will dissolve in 1 liter. What are the spectator ions in the reaction of such a dilute solution of calcium hydroxide with hydrochloric acid?

Which one of the following is not a polyprotic acid?

Identify the base in the following acid-base reaction. PbCO3(s) + H2SO4(aq) →\rightarrow→ PbSO4(s) + CO2(g) + H2O(l)

Hartmann's solution is used in intravenous therapy to replace lost body fluid and mineral salts. Hartmann's solution contains 5.00 mM potassium chloride, 2.00 mM calcium chloride, and 102 mM sodium chloride. What is the total chloride ion concentration in Hartmann's solution?

Which one of the following statements regarding a strong acid is not correct?

What is the molar concentration of sodium in a 200.0 mL solution prepared from 1.223 g of sodium phosphate (Na3PO4, 163.9 g/mol) , which is a cleaning agent, food additive, and stain remover?

Which one of the following statements regarding a weak acid is not correct?

Identify the acid in the following acid-base reaction. PbCO3(s) + H2SO4(aq) →\rightarrow→ PbSO4(s) + CO2(g) + H2O(l )

Which one of the following reaction equations is the net ionic equation for the reaction of hydrochloric acid with lithium hydroxide? All species are in aqueous solution.

Which one of the following reaction equations is the molecular equation for the reaction of hydrochloric acid with sodium hydroxide? All species are in aqueous solution.

Identify a spectator ion in the following acid-base reaction. Ca(CO3) (s) + 2HCl(aq) →\rightarrow→ CaCl2(aq) + 2H2O(l ) + CO2(g)

In its reaction with water, ammonia (NH3) __________

Chalk contains calcium carbonate. What would be the best solution for cleaning a sidewalk that a preschool class covered with smiling suns, flowers, birds, rainbows, and houses using sidewalk chalk?

Hydroxyapatite, [Ca₅(PO₄) ₃(OH) ], the major component of tooth enamel, is attacked and decomposed by acids more readily than fluorapatite, [Ca₅(PO₄) ₃F]. Which one of the following reactions is analogous to the reaction of hydroxyapatite?

If one regular antacid tablet contains 500 mg of solid CaCO₃ (100 g/mol) , how many mL of 1.0 M stomach acid (HCl) could it neutralize?

If 1.0 L of 1.0 M HCl spilled and needed to be neutralized, how many grams of the solid sodium carbonate (Na₂CO₃, 106 g/mol) would be required?

What would be the products in the overall ionic equation for the following reaction? 2HBr(aq) + 2KOH(aq) $\rightarrow$ products I. K⁺(aq) and Br ^-(aq) ; II. KH(aq) ; III. H₂O(l ) ; IV. KBr(s) ; V. BrOH(aq) ; VI. KBr(aq)

Identify the base in the following acid-base reaction. PbCO₃(s) + H₂SO₄(aq) $\rightarrow$ PbSO₄(s) + CO₂(g) + H₂O(l)

What is the molar concentration of sodium in a 200.0 mL solution prepared from 1.223 g of sodium phosphate (Na₃PO₄, 163.9 g/mol) , which is a cleaning agent, food additive, and stain remover?

Identify the acid in the following acid-base reaction. PbCO₃(s) + H₂SO₄(aq) $\rightarrow$ PbSO₄(s) + CO₂(g) + H₂O(l )

Identify a spectator ion in the following acid-base reaction. Ca(CO₃) (s) + 2HCl(aq) $\rightarrow$ CaCl₂(aq) + 2H₂O(l ) + CO₂(g)

In its reaction with water, ammonia (NH₃) __________