Question 1

What is the oxidation number of the sulfur atom in SO₄^2-?

Accepted Answer

In this compound, each oxygen atom has an oxidation state of -2, and each phosphorus atom has an oxidation state of +5. Therefore, to balance the charges, the sulfur atom must have an oxidation state of +6. Therefore, the correct answer is D.

Question 2

What is the change in oxidation state for the manganese atom in the following unbalanced reduction half reaction? MnO₄^-(aq)+ H⁺(aq)→ Mn²⁺(aq)+ H₂O(l)

Accepted Answer

In MnO₄⁻, manganese has an oxidation state of +7. In Mn²⁺, manganese has an oxidation state of +2. The change in oxidation state is +2 - (+7) = -5.

Question 3

What is the molarity of a NaOH solution if 28.2 mL of a 0.112 M H₂SO₄ solution is required to neutralize a 25.0-mL sample of the NaOH solution?

Accepted Answer

The balanced equation is H2SO4 + 2NaOH → Na2SO4 + 2H2O. Moles of H2SO4 = 0.0282 L * 0.112 M = 0.0031584 mol. Since 2 moles of NaOH react with 1 mole of H2SO4, moles of NaOH = 2 * 0.0031584 = 0.0063168 mol. Molarity of NaOH = 0.0063168 mol / 0.025 L = 0.253 M.

Question 4

Identify the oxidation state of Mg in Mg(s). Mg(s)+ 2 HCl(aq)→ MgCl₂(aq)+ H₂(g)

Accepted Answer

In its elemental form, such as Mg(s), the oxidation state of an element is always 0.

Question 5

Determine the oxidation state of Ti in Ti(SO₄)₂.

Accepted Answer

The oxidation states of oxygen and sulfur in the complex are -2 and +6, respectively. The sum of the oxidation states of all the ligands must equal the charge of the complex, which is 0 in this case. Let x be the oxidation state of Ti. Then, we can set up the following equation:

x + (-2) + 6 + (-2) + 0 + 0 + (-2) + 0 + 0 + 0 + (-2) + 0 = 0

Simplifying this equation gives:

x + 0 = 0

Therefore, the oxidation state of Ti is 0.

Question 6

In an acid-base neutralization reaction,33.74 mL of 0.500 M potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H₂SO₄ solution?

Accepted Answer

The correct answer is A because 33.74 mL of 0.500 M potassium hydroxide reacts with 50.00 mL of sulfuric acid solution. The concentration of the H2SO4 solution is 0.169 M.

Question 7

How many milliliters of 0.111 M HClO₄ solution are needed to neutralize 50.00 mL of 0.0789 M NaOH?

Accepted Answer

The answer of How many milliliters of 0.111 M HClO₄...

Question 8

Identify the oxidation state of H in HCl(aq). Ca(s)+ 2 HCl(aq)→ CaCl₂(aq)+ H₂(g)

Accepted Answer

In HCl, hydrogen typically has an oxidation state of +1, which is a common oxidation state for hydrogen when it is bonded to non-metals.

Question 9

Determine the oxidation state of nitrogen in LiNO₃.

Accepted Answer

The compound LiNOS is not a standard chemical notation, but assuming it's a hypothetical compound where nitrogen is bonded to oxygen and sulfur in some form, and lithium is present as a cation (+1), we can deduce the oxidation state of nitrogen by considering the typical oxidation states of the other elements. Oxygen usually has an oxidation state of -2, and sulfur can vary but in many compounds is -2 as well. Lithium, being an alkali metal, has a +1 oxidation state. Without specific structural information, a precise calculation is challenging, but we can infer that nitrogen must have a higher oxidation state to balance the charges, with +5 being a common oxidation state for nitrogen in compounds where it is bonded to more electronegative elements like oxygen.

Question 10

What is the oxidation number of the chromium atom in H₂CrO₄?

Accepted Answer

To determine the oxidation state of the Cr atom, we need to consider the other atoms in the compound and their known oxidation states. H = +1 S = -2 O = -2 Let x be the oxidation state of Cr Therefore, (+1) + (-2) + (x) + (-2) + (-1) + (+4) + (-2) + (-1) + (+4) + (-2) = 0 Simplifying the equation gives: x = +6 Thus, the oxidation number of the chromium atom in H₂CrO₄ is +6.

Question 11

What is the oxidation number of the oxygen atom in O₂^2-?

Accepted Answer

The oxidation number of oxygen is usually -2, except in peroxides (where it is -1) or when combined with more electronegative elements such as fluorine (where it can be positive). There are no indications in the given chemical formula that suggest any exceptions to the usual -2 oxidation number for oxygen, so the answer must be -1.

Question 12

Which of the following is an acid-base reaction?

Accepted Answer

In option B, HCl is an acid and Ca(OH)2 is a base. They react to form H2O and CaCl2, which is a salt. Therefore, it is an acid-base reaction. The other options do not involve any acid and base reacting to form a salt and hence are not acid-base reactions.

Question 13

Which of the following compounds is an Arrhenius base?

Accepted Answer

Arrhenius bases are substances that dissociate in water to produce hydroxide ions (OH-). KOH is an example of an Arrhenius base, as it dissociates in water to produce K+ and OH- ions. A and B are neither acids nor bases. HOI is an acid because it dissociates in water to produce H+ and I- ions.

Question 14

Determine the oxidation state of nitrogen in NaNO₂.

Accepted Answer

In this compound, sodium (Na) has a well-known oxidation state of +1. Oxygen (O) has an oxidation state of -2. Therefore, the total oxidation states of Na and O in the compound are +1 and -2, respectively. Now, let x be the oxidation state of nitrogen (N). Then we can write: (+1) + x + (-2) + (-1) + x + (-2) = 0 Solving for x gives x = +3. Therefore, the oxidation state of nitrogen in NaNO₂ is +3, which is the same as choice B.

Question 15

When 220.mL of 1.50 × 10^-4M hydrochloric acid is added to 135 mL of 1.75 × 10^-4 M Mg(OH)₂,the resulting solution will be

Accepted Answer

When hydrochloric acid (HCl) is added to water, it dissociates into its constituent ions, hydrogen ions (H+) and chloride ions (Cl-), as represented by the equation:

HCl → H+ + Cl-

The hydrogen ions will react with the hydroxide ions (OH-) produced by the magnesium hydroxide (Mg(OH)2), as represented by the equation:

H+ + OH- → H2O

This reaction produces water (H2O) and leaves excess hydrogen ions that make the solution acidic. Therefore, the resulting solution will be basic.

Question 16

Which of the following is a gas-evolution reaction?

Accepted Answer

A gas-evolution reaction is one in which a gas is produced as a product. In choice D, ammonia gas (NH₃) is produced, indicating it is a gas-evolution reaction.

Question 17

A solution is prepared by mixing 5.00 mL of 0.100 M HCl and 2.00 mL of 0.200 M NaCl.What is the molarity of chloride ion in this solution?

Accepted Answer

The answer of A solution is prepared by mixing 5.00...

Question 18

Determine the oxidation state of S in CaSO₄.

Accepted Answer

The compound in question seems to be a typo or a misrepresentation. However, assuming the question intends to ask about the oxidation state of sulfur (S) in a compound where it is combined with calcium (Ca) and oxygen (O), such as in calcium sulfate (CaSO4), the oxidation state of sulfur would be +6. This is determined by knowing that oxygen typically has an oxidation state of -2, and calcium typically has an oxidation state of +2. In a compound like CaSO4, for the charges to balance to zero, the sulfur must have an oxidation state of +6.

Question 19

A solution is prepared by adding 1.70 g of solid NaCl to 50.0 mL of 0.100 M CaCl₂.What is the molarity of chloride ion in the final solution? Assume that the volume of the final solution is 50.0 mL.

Accepted Answer

First, calculate the moles of NaCl added: $ \frac{1.70 \, \text{g}}{58.44 \, \text{g/mol}} = 0.0291 \, \text{mol} $. Each mole of NaCl gives 1 mole of Cl⁻. Then, calculate the moles of Cl⁻ from CaCl2: $ 50.0 \, \text{mL} \times 0.100 \, \text{M} = 0.0050 \, \text{mol} $ of CaCl2, which gives $ 0.0050 \, \text{mol} \times 2 = 0.0100 \, \text{mol} $ of Cl⁻. Total moles of Cl⁻ = $ 0.0291 + 0.0100 = 0.0391 \, \text{mol} $. Molarity of Cl⁻ = $ \frac{0.0391 \, \text{mol}}{0.0500 \, \text{L}} = 0.782 \, \text{M} $.

Question 20

Determine the oxidation state of iodine in I₂.

Accepted Answer

In I2, iodine is in its elemental form, and elements in their natural state have an oxidation state of 0.

Quiz 4: Chemical Quantities and Aqueous Reactions

What is the oxidation number of the sulfur atom in SO₄^2-?

What is the change in oxidation state for the manganese atom in the following unbalanced reduction half reaction? MnO₄^-(aq) + H⁺(aq) → Mn²⁺(aq) + H₂O(l)

What is the molarity of a NaOH solution if 28.2 mL of a 0.112 M H₂SO₄ solution is required to neutralize a 25.0-mL sample of the NaOH solution?

Identify the oxidation state of Mg in Mg(s) . Mg(s) + 2 HCl(aq) → MgCl₂(aq) + H₂(g)

Determine the oxidation state of Ti in Ti(SO₄) ₂.

In an acid-base neutralization reaction,33.74 mL of 0.500 M potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H₂SO₄ solution?

How many milliliters of 0.111 M HClO₄ solution are needed to neutralize 50.00 mL of 0.0789 M NaOH?

Identify the oxidation state of H in HCl(aq) . Ca(s) + 2 HCl(aq) → CaCl₂(aq) + H₂(g)

Determine the oxidation state of nitrogen in LiNO₃.

What is the oxidation number of the chromium atom in H₂CrO₄?

What is the oxidation number of the oxygen atom in O₂^2-?

Which of the following is an acid-base reaction?

Which of the following compounds is an Arrhenius base?

Determine the oxidation state of nitrogen in NaNO₂.

When 220.mL of 1.50 × 10^-4M hydrochloric acid is added to 135 mL of 1.75 × 10^-4 M Mg(OH) ₂,the resulting solution will be

Which of the following is a gas-evolution reaction?

A solution is prepared by mixing 5.00 mL of 0.100 M HCl and 2.00 mL of 0.200 M NaCl.What is the molarity of chloride ion in this solution?

Determine the oxidation state of S in CaSO₄.

A solution is prepared by adding 1.70 g of solid NaCl to 50.0 mL of 0.100 M CaCl₂.What is the molarity of chloride ion in the final solution? Assume that the volume of the final solution is 50.0 mL.

Determine the oxidation state of iodine in I₂.

Quiz 4: Chemical Quantities and Aqueous Reactions

What is the oxidation number of the sulfur atom in SO42-?

What is the change in oxidation state for the manganese atom in the following unbalanced reduction half reaction? MnO4- (aq) + H+(aq) → Mn2+(aq) + H2O(l)

What is the molarity of a NaOH solution if 28.2 mL of a 0.112 M H2SO4 solution is required to neutralize a 25.0-mL sample of the NaOH solution?

Identify the oxidation state of Mg in Mg(s) . Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g)

Determine the oxidation state of Ti in Ti(SO4) 2.

In an acid-base neutralization reaction,33.74 mL of 0.500 M potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H2SO4 solution?

How many milliliters of 0.111 M HClO4 solution are needed to neutralize 50.00 mL of 0.0789 M NaOH?

Identify the oxidation state of H in HCl(aq) . Ca(s) + 2 HCl(aq) → CaCl2(aq) + H2(g)

Determine the oxidation state of nitrogen in LiNO3.

What is the oxidation number of the chromium atom in H2CrO4?

What is the oxidation number of the oxygen atom in O22-?

Which of the following is an acid-base reaction?

Which of the following compounds is an Arrhenius base?

Determine the oxidation state of nitrogen in NaNO2.

When 220.mL of 1.50 × 10-4 M hydrochloric acid is added to 135 mL of 1.75 × 10-4 M Mg(OH) 2,the resulting solution will be

Which of the following is a gas-evolution reaction?

A solution is prepared by mixing 5.00 mL of 0.100 M HCl and 2.00 mL of 0.200 M NaCl.What is the molarity of chloride ion in this solution?

Determine the oxidation state of S in CaSO4.

A solution is prepared by adding 1.70 g of solid NaCl to 50.0 mL of 0.100 M CaCl2.What is the molarity of chloride ion in the final solution? Assume that the volume of the final solution is 50.0 mL.

Determine the oxidation state of iodine in I2.

What is the oxidation number of the sulfur atom in SO₄^2-?

What is the change in oxidation state for the manganese atom in the following unbalanced reduction half reaction? MnO₄^-(aq) + H⁺(aq) → Mn²⁺(aq) + H₂O(l)

What is the molarity of a NaOH solution if 28.2 mL of a 0.112 M H₂SO₄ solution is required to neutralize a 25.0-mL sample of the NaOH solution?

Identify the oxidation state of Mg in Mg(s) . Mg(s) + 2 HCl(aq) → MgCl₂(aq) + H₂(g)

Determine the oxidation state of Ti in Ti(SO₄) ₂.

In an acid-base neutralization reaction,33.74 mL of 0.500 M potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H₂SO₄ solution?

How many milliliters of 0.111 M HClO₄ solution are needed to neutralize 50.00 mL of 0.0789 M NaOH?

Identify the oxidation state of H in HCl(aq) . Ca(s) + 2 HCl(aq) → CaCl₂(aq) + H₂(g)

Determine the oxidation state of nitrogen in LiNO₃.

What is the oxidation number of the chromium atom in H₂CrO₄?

What is the oxidation number of the oxygen atom in O₂^2-?

Determine the oxidation state of nitrogen in NaNO₂.

When 220.mL of 1.50 × 10^-4M hydrochloric acid is added to 135 mL of 1.75 × 10^-4 M Mg(OH) ₂,the resulting solution will be

Determine the oxidation state of S in CaSO₄.

A solution is prepared by adding 1.70 g of solid NaCl to 50.0 mL of 0.100 M CaCl₂.What is the molarity of chloride ion in the final solution? Assume that the volume of the final solution is 50.0 mL.

Determine the oxidation state of iodine in I₂.