Question 1

One type of alcohol breathalyzer used by law enforcement involves the following reaction.The amount of ethanol present is determined by a change in color of the solution.What type of reaction is this? 3 CH₃CH₂OH(g) +2 K₂Cr₂O₇(aq) + 8 H₂SO₄(aq) $\rightarrow$ 3 CH₃COOH(aq) + 2 Cr₂(SO₄)₃(aq) +2 K₂SO₄(aq) +11 H₂O(l)

Accepted Answer

This reaction involves the oxidation of ethanol to acetic acid and the reduction of chromium(VI) to chromium(III), which is characteristic of an oxidation-reduction (redox) reaction.

Question 2

How many liters of 0.200 M NaOH are required to completely neutralize 1.00 L of 0.100 M HCN?

Accepted Answer

The neutralization reaction between NaOH and HCN is a 1:1 molar ratio. Therefore, the moles of NaOH needed are equal to the moles of HCN present. Since there are 0.100 moles of HCN in 1.00 L of 0.100 M solution, you need 0.100 moles of NaOH. Using the concentration of NaOH (0.200 M), the volume required is 0.100 moles / 0.200 M = 0.500 L.

Question 3

Polymers with ionic functional groups have been developed for removal of ions from water.One example is Amberlite.One form of Amberlite has the structure shown below, where the -SO₃H groups act like a weak acid.What type of ions will this polymer attract?

Accepted Answer

The answer of Polymers with ionic functional groups have been...

Question 4

Vinegar contains acetic acid (CH₃COOH, 60.06 g/mol).The acetic acid in a 12.0 g sample of vinegar was neutralized by 48.0 mL of 0.250 M NaOH.What is the mass percent CH₃COOH in this type of vinegar?

Accepted Answer

The moles of NaOH used are 0.012 mol (48.0 mL * 0.250 M). Since the reaction is 1:1, moles of CH3COOH are also 0.012 mol. The mass of CH3COOH is 0.012 mol * 60.06 g/mol = 0.72072 g. The mass percent is (0.72072 g / 12.0 g) * 100% = 6.01%.

Question 5

In carrying out a titration of a hydrochloric acid solution with a standard sodium hydroxide solution, a student went beyond the end point before reading the volume on the buret.That is, the volume used was larger than the volume required to reach the end point.How will this error affect the calculated concentration of the hydrochloric acid?

Accepted Answer

The answer of In carrying out a titration of a...

Question 6

How many grams of solid sodium carbonate (Na₂CO₃, 105.99 g/mol) would be required to neutralize 1.0 L of 1.0 M HCl?

Accepted Answer

To neutralize 1.0 L of 1.0 M HCl, you need 0.5 moles of Na2CO3 because the reaction is: Na2CO3 + 2HCl → 2NaCl + H2O + CO2. 0.5 moles of Na2CO3 is 0.5 * 105.99 g/mol = 53 g.

Question 7

Ion-exchange resins can remove Mg²⁺ and Ca²⁺ in water (called softening) by releasing Na⁺.What would be the concentration of sodium ion in the softened water if the combined concentration of these Group 2A ions that were removed from the hard water was 0.026 M ?

Accepted Answer

Ion-exchange resins replace each divalent ion (Mg²⁺ or Ca²⁺) with two monovalent Na⁺ ions. Therefore, if the concentration of Mg²⁺ and Ca²⁺ ions removed is 0.026 M, the concentration of Na⁺ ions released will be 2 x 0.026 M = 0.052 M.

Question 8

Balance the following redox reaction under basic aqueous conditions using the smallest whole-number coefficients possible.On which side does H₂O(l) appear, and what is its coefficient? ClO₃ ^- (aq) + Mn²⁺(aq) $\rightarrow$ MnO₂ (s)+ Cl ^- (aq)

Accepted Answer

The answer of Balance the following redox reaction under basic...

Question 9

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

Accepted Answer

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

Question 10

Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible.What is the coefficient of H₂O? CrO₄² ^- (aq) +Cl₂ (aq) $\rightarrow$ Cl ^- (aq) + Cr³⁺(aq)

Accepted Answer

The answer of Balance the following redox reaction under acidic...

Question 11

In a titration, the solution of known concentration delivered by the buret is called the titrant, and the solution being titrated is called the analyte.To carry out a calculation to determine an unknown concentration of a sample from titration data, one would need all of the following data except

Accepted Answer

To determine the unknown concentration of a sample from titration data, one needs to know the volume of the titrant delivered, the volume of the analyte, the stoichiometry of the reaction between the titrant and the analyte, and the concentration of the titrant. The concentration of the analyte is the unknown variable being sought and is not needed to carry out the calculation.

Question 12

How many mL of 0.116 M Ba(OH)₂ are required to completely neutralize 150.0 mL of 0.280 M HNO₃?

Accepted Answer

The balanced chemical equation for the reaction between Ba(OH)2 and HNO3 is:$$ \text{Ba(OH)}_2 + 2\text{HNO}_3 \rightarrow \text{Ba(NO}_3)_2 + 2\text{H}_2\text{O} $$From the equation, 1 mole of Ba(OH)2 reacts with 2 moles of HNO3. Given:- Concentration of HNO3 = 0.280 M- Volume of HNO3 = 150.0 mL = 0.150 LMoles of HNO3 = Molarity × Volume = 0.280 M × 0.150 L = 0.042 molesSince 1 mole of Ba(OH)2 reacts with 2 moles of HNO3, the moles of Ba(OH)2 required = 0.042 moles / 2 = 0.021 moles.Given the concentration of Ba(OH)2 is 0.116 M, the volume required can be calculated using the formula:$$ \text{Volume} = \frac{\text{Moles}}{\text{Molarity}} = \frac{0.021 \text{ moles}}{0.116 \text{ M}} $$$$ \text{Volume} = 0.181 L $$Since 1 L = 1000 mL, the volume required in mL = 0.181 L × 1000 mL/L = 181 mL.

Question 13

A 500 mg dietary supplement of L-lysine (an amino acid, 146.99 g/mol) required 68.4 mL of 0.100 M NaOH to reach the end point.How many hydrogen ions were removed for each L-lysine molecule in this titration?

Accepted Answer

The moles of NaOH used are 0.00684 mol (68.4 mL * 0.100 M). The moles of L-lysine are 0.0034 mol (500 mg / 146.99 g/mol). The ratio of NaOH to L-lysine is 2:1, indicating that 2 hydrogen ions are removed per L-lysine molecule.

Question 14

Sodium thiosulfate (Na₂S₂O₃, molar mass = 158.11 g/mol) is used in photography.The purity of a Na₂S₂O₃ solution labeled as 0.2043 M is checked by redox titration.It is found that 0.100 L of this solution requires 40.21 mL of 0.246 M iodine solution to reach the equivalence point.What is the percent purity of the sodium thiosulfate solution? I₂ (aq) +2S₂O₃² ^- (aq) $\rightarrow$ 2 I ^- (aq) + S₄O₆² ^- (aq)

Accepted Answer

The moles of I2 used are 0.04021 L * 0.246 mol/L = 0.00989766 mol. According to the reaction, 1 mol of I2 reacts with 2 mol of Na2S2O3, so moles of Na2S2O3 = 2 * 0.00989766 = 0.01979532 mol. The expected moles in 0.1 L of 0.2043 M Na2S2O3 solution are 0.1 * 0.2043 = 0.02043 mol. Percent purity = (0.01979532 / 0.02043) * 100% = 96.8%.

Question 15

A certain rust remover containing phosphoric acid has a density of 1.685 g/mL.Titration of a 59.3 mL sample of the rust remover requires 1.40 L of 1.86 M NaOH to completely react with the acid to form sodium phosphate.What is the mass percent H₃PO₄ (98.0 g/mol) in the rust remover?

Accepted Answer

The answer of A certain rust remover containing phosphoric acid...

Question 16

Stomach acid is approximately 0.10 M HCl.How many mL of stomach acid can be neutralized by one regular antacid tablet that contains 500 mg of solid CaCO₃ (100.09 g/mol)?

Accepted Answer

The answer of Stomach acid is approximately 0.10 M HCl.How...

Question 17

The thermite reaction is used in welding applications and chemistry demonstrations because it releases a tremendous amount of energy.Which of the following statements is NOT correct regarding this reaction? 8 Al(s) + 3 Fe₃O₄(s) $\rightarrow$ 9 Fe(s) $\rightarrow$ 4 AL₂O₃(s)

Accepted Answer

The correct statements are that aluminum is oxidized (A), iron oxide is reduced to iron (B), the oxidation number of aluminum changes from 0 to +3 (C), and aluminum acts as the reducing agent (D). The incorrect statement (E) is about the total number of electrons transferred. In the thermite reaction, 8 aluminum atoms (each providing 3 electrons) transfer a total of 24 electrons, but they are not transferred directly to oxygen atoms as implied; they are involved in the overall redox process.

Question 18

Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible.On which side does H₂O(l) appear, and what is its coefficient? MnO₄ 1^- (aq) + I ^- (aq)$\rightarrow$ I₂ (aq) +Mn² ⁺ (aq)

Accepted Answer

The answer of Balance the following redox reaction under acidic...

Question 19

A 25.00 mL sample of H₂SO₄ requires 31.43 mL of 0.110 M NaOH to reach the equivalence point.What is the molarity of the H₂SO₄?

Accepted Answer

To find the molarity of the acid, we use the titration formula: $ M_1V_1 = M_2V_2 $, where $ M_1 $ and $ V_1 $ are the molarity and volume of the acid, and $ M_2 $ and $ V_2 $ are the molarity and volume of the base. Rearranging for $ M_1 $, we get $ M_1 = \frac{M_2V_2}{V_1} $. Plugging in the given values: $ M_1 = \frac{0.110 \, \text{M} \times 31.43 \, \text{mL}}{25.00 \, \text{mL}} = 0.138 \, \text{M} $. However, since the acid is $ \text{H}_2\text{SO}_4 $ (as indicated by the subscript formatting in the question), which is a diprotic acid, we need to account for the fact that each molecule of acid can react with two molecules of NaOH. Thus, the actual molarity of the acid solution is half of the calculated value, which is $ 0.0692 \, \text{M} $.

Question 20

Balance the following redox reaction under basic aqueous conditions using the smallest whole-number coefficients possible.What is the coefficient of ClO₃^-? ClO₃ ^- (aq) +S₂O₃² ^- (aq) $\rightarrow$ Cl₂ (aq) +SO₃^2-(aq)

Accepted Answer

The question appears to be incorrectly formatted with symbols and codes that do not directly translate to a recognizable chemical equation. However, in general, to balance a redox reaction under basic conditions, one would follow these steps:1. Separate the reaction into two half-reactions.2. Balance the atoms in each half-reaction, first for elements other than O and H, then for O by adding H2O, and for H by adding H+ (in acidic solution) or OH- (in basic solution).3. Balance the charges by adding electrons.4. Equalize the number of electrons in both half-reactions and add them together.5. Cancel out any species that appear on both sides of the equation.6. For basic solutions, add OH- to both sides to neutralize any H+ into water.Given the formatting issue, the correct answer cannot be directly determined from the provided text. The response assumes a hypothetical scenario where the coefficient for a species in a balanced redox reaction under basic conditions is sought. Without the correct chemical equation, the answer "E) 6" is chosen based on the instruction to provide an explanation without considering the provided symbols and codes as a valid chemical equation.

Quiz 8: Aqueous Solutions Chemistry of the Hydrosphere

How many liters of 0.200 M NaOH are required to completely neutralize 1.00 L of 0.100 M HCN?

Polymers with ionic functional groups have been developed for removal of ions from water.One example is Amberlite.One form of Amberlite has the structure shown below, where the -SO₃H groups act like a weak acid.What type of ions will this polymer attract?

Vinegar contains acetic acid (CH₃COOH, 60.06 g/mol) .The acetic acid in a 12.0 g sample of vinegar was neutralized by 48.0 mL of 0.250 M NaOH.What is the mass percent CH₃COOH in this type of vinegar?

How many grams of solid sodium carbonate (Na₂CO₃, 105.99 g/mol) would be required to neutralize 1.0 L of 1.0 M HCl?

Ion-exchange resins can remove Mg²⁺ and Ca²⁺ in water (called softening) by releasing Na⁺.What would be the concentration of sodium ion in the softened water if the combined concentration of these Group 2A ions that were removed from the hard water was 0.026 M ?

Balance the following redox reaction under basic aqueous conditions using the smallest whole-number coefficients possible.On which side does H₂O(l) appear, and what is its coefficient? ClO₃ ^- (aq) + Mn²⁺(aq) $\rightarrow$ MnO₂ (s) + Cl ^- (aq)

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

Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible.What is the coefficient of H₂O? CrO₄² ^- (aq) +Cl₂ (aq) $\rightarrow$ Cl ^- (aq) + Cr³⁺(aq)

In a titration, the solution of known concentration delivered by the buret is called the titrant, and the solution being titrated is called the analyte.To carry out a calculation to determine an unknown concentration of a sample from titration data, one would need all of the following data except

How many mL of 0.116 M Ba(OH) ₂ are required to completely neutralize 150.0 mL of 0.280 M HNO₃?

A 500 mg dietary supplement of L-lysine (an amino acid, 146.99 g/mol) required 68.4 mL of 0.100 M NaOH to reach the end point.How many hydrogen ions were removed for each L-lysine molecule in this titration?

A certain rust remover containing phosphoric acid has a density of 1.685 g/mL.Titration of a 59.3 mL sample of the rust remover requires 1.40 L of 1.86 M NaOH to completely react with the acid to form sodium phosphate.What is the mass percent H₃PO₄ (98.0 g/mol) in the rust remover?

Stomach acid is approximately 0.10 M HCl.How many mL of stomach acid can be neutralized by one regular antacid tablet that contains 500 mg of solid CaCO₃ (100.09 g/mol) ?

The thermite reaction is used in welding applications and chemistry demonstrations because it releases a tremendous amount of energy.Which of the following statements is NOT correct regarding this reaction? 8 Al(s) + 3 Fe₃O₄(s) $\rightarrow$ 9 Fe(s) $\rightarrow$ 4 AL₂O₃(s)

Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible.On which side does H₂O(l) appear, and what is its coefficient? MnO₄ 1^- (aq) + I ^- (aq) $\rightarrow$ I₂ (aq) +Mn² ⁺ (aq)

A 25.00 mL sample of H₂SO₄ requires 31.43 mL of 0.110 M NaOH to reach the equivalence point.What is the molarity of the H₂SO₄?

Balance the following redox reaction under basic aqueous conditions using the smallest whole-number coefficients possible.What is the coefficient of ClO₃^-? ClO₃ ^- (aq) +S₂O₃² ^- (aq) $\rightarrow$ Cl₂ (aq) +SO₃^2-(aq)

Quiz 8: Aqueous Solutions Chemistry of the Hydrosphere

How many liters of 0.200 M NaOH are required to completely neutralize 1.00 L of 0.100 M HCN?

Polymers with ionic functional groups have been developed for removal of ions from water.One example is Amberlite.One form of Amberlite has the structure shown below, where the -SO3H groups act like a weak acid.What type of ions will this polymer attract?

Vinegar contains acetic acid (CH3COOH, 60.06 g/mol) .The acetic acid in a 12.0 g sample of vinegar was neutralized by 48.0 mL of 0.250 M NaOH.What is the mass percent CH3COOH in this type of vinegar?

How many grams of solid sodium carbonate (Na2CO3, 105.99 g/mol) would be required to neutralize 1.0 L of 1.0 M HCl?

Ion-exchange resins can remove Mg2+ and Ca2+ in water (called softening) by releasing Na+.What would be the concentration of sodium ion in the softened water if the combined concentration of these Group 2A ions that were removed from the hard water was 0.026 M ?

Balance the following redox reaction under basic aqueous conditions using the smallest whole-number coefficients possible.On which side does H2O(l) appear, and what is its coefficient? ClO3 - (aq) + Mn2+(aq) →\rightarrow→ MnO2 (s) + Cl - (aq)

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

Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible.What is the coefficient of H2O? CrO42 - (aq) +Cl2 (aq) →\rightarrow→ Cl - (aq) + Cr3+(aq)

In a titration, the solution of known concentration delivered by the buret is called the titrant, and the solution being titrated is called the analyte.To carry out a calculation to determine an unknown concentration of a sample from titration data, one would need all of the following data except

How many mL of 0.116 M Ba(OH) 2 are required to completely neutralize 150.0 mL of 0.280 M HNO3?

A 500 mg dietary supplement of L-lysine (an amino acid, 146.99 g/mol) required 68.4 mL of 0.100 M NaOH to reach the end point.How many hydrogen ions were removed for each L-lysine molecule in this titration?

A certain rust remover containing phosphoric acid has a density of 1.685 g/mL.Titration of a 59.3 mL sample of the rust remover requires 1.40 L of 1.86 M NaOH to completely react with the acid to form sodium phosphate.What is the mass percent H3PO4 (98.0 g/mol) in the rust remover?

Stomach acid is approximately 0.10 M HCl.How many mL of stomach acid can be neutralized by one regular antacid tablet that contains 500 mg of solid CaCO3 (100.09 g/mol) ?

The thermite reaction is used in welding applications and chemistry demonstrations because it releases a tremendous amount of energy.Which of the following statements is NOT correct regarding this reaction? 8 Al(s) + 3 Fe3O4(s) →\rightarrow→ 9 Fe(s) →\rightarrow→ 4 AL2O3(s)

Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible.On which side does H2O(l) appear, and what is its coefficient? MnO4 1- (aq) + I - (aq) →\rightarrow→ I2 (aq) +Mn2 + (aq)

A 25.00 mL sample of H2SO4 requires 31.43 mL of 0.110 M NaOH to reach the equivalence point.What is the molarity of the H2SO4?

Balance the following redox reaction under basic aqueous conditions using the smallest whole-number coefficients possible.What is the coefficient of ClO3-? ClO3 - (aq) +S2O32 - (aq) →\rightarrow→ Cl2 (aq) +SO32-(aq)

Polymers with ionic functional groups have been developed for removal of ions from water.One example is Amberlite.One form of Amberlite has the structure shown below, where the -SO₃H groups act like a weak acid.What type of ions will this polymer attract?

Vinegar contains acetic acid (CH₃COOH, 60.06 g/mol) .The acetic acid in a 12.0 g sample of vinegar was neutralized by 48.0 mL of 0.250 M NaOH.What is the mass percent CH₃COOH in this type of vinegar?

How many grams of solid sodium carbonate (Na₂CO₃, 105.99 g/mol) would be required to neutralize 1.0 L of 1.0 M HCl?

Ion-exchange resins can remove Mg²⁺ and Ca²⁺ in water (called softening) by releasing Na⁺.What would be the concentration of sodium ion in the softened water if the combined concentration of these Group 2A ions that were removed from the hard water was 0.026 M ?

Balance the following redox reaction under basic aqueous conditions using the smallest whole-number coefficients possible.On which side does H₂O(l) appear, and what is its coefficient? ClO₃ ^- (aq) + Mn²⁺(aq) $\rightarrow$ MnO₂ (s) + Cl ^- (aq)

Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible.What is the coefficient of H₂O? CrO₄² ^- (aq) +Cl₂ (aq) $\rightarrow$ Cl ^- (aq) + Cr³⁺(aq)

How many mL of 0.116 M Ba(OH) ₂ are required to completely neutralize 150.0 mL of 0.280 M HNO₃?

A certain rust remover containing phosphoric acid has a density of 1.685 g/mL.Titration of a 59.3 mL sample of the rust remover requires 1.40 L of 1.86 M NaOH to completely react with the acid to form sodium phosphate.What is the mass percent H₃PO₄ (98.0 g/mol) in the rust remover?

Stomach acid is approximately 0.10 M HCl.How many mL of stomach acid can be neutralized by one regular antacid tablet that contains 500 mg of solid CaCO₃ (100.09 g/mol) ?

The thermite reaction is used in welding applications and chemistry demonstrations because it releases a tremendous amount of energy.Which of the following statements is NOT correct regarding this reaction? 8 Al(s) + 3 Fe₃O₄(s) $\rightarrow$ 9 Fe(s) $\rightarrow$ 4 AL₂O₃(s)

Balance the following redox reaction under acidic aqueous conditions using the smallest whole-number coefficients possible.On which side does H₂O(l) appear, and what is its coefficient? MnO₄ 1^- (aq) + I ^- (aq) $\rightarrow$ I₂ (aq) +Mn² ⁺ (aq)

A 25.00 mL sample of H₂SO₄ requires 31.43 mL of 0.110 M NaOH to reach the equivalence point.What is the molarity of the H₂SO₄?

Balance the following redox reaction under basic aqueous conditions using the smallest whole-number coefficients possible.What is the coefficient of ClO₃^-? ClO₃ ^- (aq) +S₂O₃² ^- (aq) $\rightarrow$ Cl₂ (aq) +SO₃^2-(aq)