Question 1

Which of the compounds H₂C₂O₄,Ca(OH)₂,KOH,and HI behave as bases when they are dissolved in water?

Accepted Answer

Ca(OH)2 and KOH are strong bases because they completely dissociate in water to produce hydroxide ions (OH-) which can accept a proton (H+) from the solvent or other sources. 
HS2B12S2B0CS2B12S2B0OS2B14S2B0 and HI are not bases but rather acids. HI is a strong acid and will dissociate into H+ and I- in water, while HS2B12S2B0CS2B12S2B0OS2B14S2B0 is a weak acid that will partly dissociate into H+ and HS2B12S2B0CS2B12S2B0O- ions.

Question 2

In an acid-base neutralization reaction,38.74 mL of 0.500 mol L^-1 potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H₂SO₄ solution?

Accepted Answer

The balanced chemical equation for the reaction between potassium hydroxide (KOH) and sulfuric acid (H2SO4) is 2KOH + H2SO4 → K2SO4 + 2H2O. This shows that 2 moles of KOH react with 1 mole of H2SO4. Given that 38.74 mL of 0.500 M KOH is used, the moles of KOH are (38.74 mL) * (0.500 mol/L) = 0.01937 mol. Since the ratio of KOH to H2SO4 is 2:1, the moles of H2SO4 needed are half of that of KOH, which is 0.01937 mol / 2 = 0.009685 mol. The concentration of H2SO4 is then the moles of H2SO4 divided by the volume of the H2SO4 solution in liters, which is 0.009685 mol / 0.05000 L = 0.194 mol/L.

Question 3

Which pair of compounds is soluble in water?

Accepted Answer

LiI and Ca(NO3)2 are soluble in water. Lithium iodide (LiI) is soluble due to the solubility of most alkali metal salts, and calcium nitrate (Ca(NO3)2) is soluble because all nitrates are soluble in water.

Question 4

Lead ions can be precipitated from aqueous solutions by the addition of aqueous iodide: (aq)+ (aq)→ (s) Lead iodide is virtually insoluble in water so that the reaction appears to go to completion.How many millilitres of 3.550 mol L^-1 HI(aq)must be added to a solution containing 0.700 mol of To completely precipitate the lead?

Accepted Answer

The balanced chemical equation for this reaction is:

Pb(NO3)2(aq) + 2HI(aq) → PbI2(s) + 2HNO3(aq)

From the equation, we can see that 2 moles of HI are required to completely precipitate 1 mole of Pb(NO3)2. This means that the number of moles of HI required to precipitate 0.7 moles of Pb(NO3)2 is:

0.7 mol Pb(NO3)2 × 2 mol HI/1 mol Pb(NO3)2 = 1.4 mol HI

We can use the molarity of the HI solution to calculate the volume required:

1.4 mol HI × 1 L/3.55 mol = 0.394 L or 394 mL

Therefore, the best choice is (B) 394 mL.

Question 5

What reagent could be used to separate Br^- from CH₃CO₂^-when added to an aqueous solution containing both?

Accepted Answer

AgNO3 can selectively react with Br- to form a precipitate of AgBr. This allows for the separation of Br^- from CH₃CO₂^- in aqueous solution. Ba(OH)2 would not be effective as it would precipitate all ions containing ₂. CuSO4 would not be effective as neither Br- nor CO₂ are able to react with it. NaI could potentially react with both Br- and CO₂, but AgNO3 is a more reliable and selective option.

Question 6

The mixing of which pair of reactants will result in a precipitation reaction?

Accepted Answer

Choice C involves the mixing of potassium sulfide and mercury (II) sulfide which will yield a precipitate of mercury (II) sulfide. A precipitation reaction occurs when two aqueous solutions are mixed, and a solid substance is formed, which is insoluble in water. All the other choices result in the formation of soluble products, and hence there will be no precipitation reaction.

Question 7

The mixing of which pair of reactants will result in a precipitation reaction?

Accepted Answer

When Ba(NO3)2 and Na2CO3 are mixed, they react to form BaCO3, which is insoluble in water and will precipitate out of solution.

Question 8

Which of the following compounds is an Arrhenius base?

Accepted Answer

CsOH (cesium hydroxide) is an Arrhenius base because it dissociates in water to produce hydroxide ions (OH-). The other options either do not have hydroxide ions (CHOCl) or do not dissociate in water to produce hydroxide ions (CH3COOH).

Question 9

According to the balanced equation shown below,4.00 moles of oxalic acid,H₂C₂O₄,reacts with ________ moles of permanganate,MnO₄^-. 5 H₂C₂O₄(aq)+ 2 MnO₄^-(aq)+ 6 H⁺^(aq)→ 10 CO₂(g)+ Mn²⁺(aq)+ 8 H₂O(l)

Accepted Answer

According to the balanced chemical equation, 5 moles of oxalic acid react with 2 moles of permanganate. Therefore, 4.00 moles of oxalic acid would react with $4.00 \times \frac{2}{5} = 1.60$ moles of permanganate.

Question 10

Silver ions can be precipitated from aqueous solutions by the addition of aqueous chloride: (aq)+ (aq)→ AgCl(s) Silver chloride is virtually insoluble in water so that the reaction appears to go to completion.How many grams of solid NaCl must be added to 25.0 mL of 0.366 mol L^-1 (aq)solution to completely precipitate the silver?

Accepted Answer

First, we need to determine how many moles of Ag+ are present in 25.0 mL of the solution:

0.366 mol/L x 0.0250 L = 0.00915 mol Ag+

According to the balanced equation, 1 mole of Ag+ reacts with 1 mole of Cl-, so we need 0.00915 mol of Cl- to completely precipitate the silver ions.

Since NaCl dissociates into Na+ and Cl-, we only need to consider the moles of Cl- provided by NaCl. The molar mass of NaCl is 58.44 g/mol, so we can calculate the mass of NaCl required:

0.00915 mol Cl- x 1 mol NaCl/1 mol Cl- x 58.44 g/mol = 0.535 g NaCl

Therefore, the correct answer is (C).

Question 11

When dissolved in water,KOH behaves as:

Accepted Answer

KOH is a strong base, and when it dissolves in water, it dissociates into K+ and OH- ions. Therefore, it forms K⁺ and OH^- ions, making choice C the correct answer.

Question 12

Identify the coefficient of Ca(OH)₂(aq)when the following reaction is balanced,and determine the number of millilitres of 0.00300 mol L-1 phosphoric acid required to neutralize 45.00 mL of 0.00150 mol L^-1 calcium hydroxide. (unbalanced)Ca(OH)₂(aq)+ H₃PO₄(aq)→ Ca₃(PO₄)₂(aq)+ H₂O(l)

Accepted Answer

The coefficient of Ca(OH)2 is 1, and the coefficient of H3PO4 is 3 in the balanced equation: 3Ca(OH)2(aq) + 2H3PO4(aq) → Ca3(PO4)2(s) + 6H2O(l). Therefore, one mole of Ca(OH)2 will react with three moles of H3PO4. The number of moles of H3PO4 in 45.00 mL of 0.00150 mol L-1 solution is 0.0675 mmol. To neutralize this, we need 0.0675/3 = 0.0225 mmol of H3PO4, which is present in 0.0225/0.00300 = 7.50 mL of 0.00300 mol L-1 H3PO4. Therefore, the best choice is B, which is closest to this value.

Question 13

When 280 mL of 1.50 × 10^-4mol L^-1 hydrochloric acid is added to 105 mL of 1.75 × 10^-4 mol L^-1 Mg(OH)₂,the resulting solution will be:

Accepted Answer

To determine the resulting solution's nature, calculate the moles of HCl and Mg(OH)2. For HCl: $280 \, \text{mL} \times 1.50 \times 10^{-4} \, \text{mol/L} = 0.042 \, \text{mol}$. For Mg(OH)2: $105 \, \text{mL} \times 1.75 \times 10^{-4} \, \text{mol/L} = 0.018375 \, \text{mol}$. The reaction between HCl and Mg(OH)2 is $2\text{HCl} + \text{Mg(OH)}_2 \rightarrow \text{MgCl}_2 + 2\text{H}_2\text{O}$. Each mole of Mg(OH)2 reacts with 2 moles of HCl. Here, $0.018375 \, \text{mol}$ of Mg(OH)2 would need $0.03675 \, \text{mol}$ of HCl to neutralize completely. Since there are $0.042 \, \text{mol}$ of HCl initially, there will be excess HCl after the reaction, making the solution acidic.

Question 14

What reagent could not be used to separate Br^- from CO₃^2- when added to an aqueous solution containing both?

Accepted Answer

AgNO3 would not be able to separate Br^- from CO₃^2- since both compounds are not Ag+ precipitants (they do not form insoluble Ag+ salts). The other reagents (Ca(NO3)2, Cu(NO3)2, Fe(NO3)3) might be able to precipitate one of the compounds, allowing for separation.

Question 15

Which of the following compounds is an Arrhenius base?

Accepted Answer

Arrhenius bases are substances that increase the concentration of hydroxide ions (OH-) when dissolved in water. Choice B, which represents CH3CH2NH2 (ethylamine), is an Arrhenius base because it can donate an OH- ion in aqueous solution.

Question 16

How many millilitres of 0.550 mol L^-1 hydriodic acid are needed to react with 15.00 mL of 0.217 mol L^-1 CsOH? HI(aq)+ CsOH(aq)→ CsI(aq)+ H₂O(l)

Accepted Answer

First, balance the equation: HI(aq) + CsOH(aq) → CsI(aq) + H2O(l) Next, use the mole ratio from the balanced equation to find the moles of L^-1 HI that will react with the given amount of L^-1 CsOH: 0.217 mol CsOH x (1 mol HI / 1 mol CsOH) = 0.217 mol HI Finally, use the concentration and volume of the L^-1 HI solution to find the amount of L^-1 HI that contains 0.217 mol: 0.550 mol/L x V = 0.217 mol V = 0.217 mol / 0.550 mol/L = 0.395 L = 395 mL Therefore, the required amount of L^-1 HI is 5.92 mL.

Question 17

Which of the following compounds is an Arrhenius base?

Accepted Answer

An Arrhenius base is a substance that increases the concentration of hydroxide ions (OH-) in aqueous solution. C₆H₅NH₂ (aniline) can act as a base by accepting a proton, but it is not an Arrhenius base. None of the given options are classic Arrhenius bases, but D is the closest as it can act as a base in a broader sense.

Question 18

Which of the compounds of H₂C₂O_4, Ca(OH)₂,KOH,and HI behave as acids when they are dissolved in water?

Accepted Answer

HSO4- (hydrogen sulfate) and HI (hydroiodic acid) behave as acids in water because they donate protons (H+) to the water, which is a characteristic behavior of acids.

Question 19

Which one of the following compounds behaves as an acid when dissolved in water?

Accepted Answer

HI is a binary acid, meaning it releases H+ ions when dissolved in water, making it behave as an acid. RaO is a metal oxide, and RbOH is an alkali metal hydroxide, both of which behave as bases when dissolved in water. C₄H₁₀ is a long and unlikely compound that does not exist.

Question 20

A solution is prepared by mixing 50.0 mL of 0.100 mol L^-1 HCl and 10.0 mL of 0.200 mol L^-1 NaCl.What is the molarity of chloride ion in this solution?

Accepted Answer

The answer of A solution is prepared by mixing 50.0...

Quiz 5: Introduction to Reactions in Aqueous Solutions

Which of the compounds H₂C₂O₄,Ca(OH) ₂,KOH,and HI behave as bases when they are dissolved in water?

In an acid-base neutralization reaction,38.74 mL of 0.500 mol L^-1 potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H₂SO₄ solution?

Which pair of compounds is soluble in water?

What reagent could be used to separate Br^- from CH₃CO₂^-when added to an aqueous solution containing both?

The mixing of which pair of reactants will result in a precipitation reaction?

The mixing of which pair of reactants will result in a precipitation reaction?

Which of the following compounds is an Arrhenius base?

According to the balanced equation shown below,4.00 moles of oxalic acid,H₂C₂O₄,reacts with ________ moles of permanganate,MnO₄^-. 5 H₂C₂O₄(aq) + 2 MnO₄^-(aq) + 6 H⁺^(aq) → 10 CO₂(g) + Mn²⁺(aq) + 8 H₂O(l)

When dissolved in water,KOH behaves as:

When 280 mL of 1.50 × 10^-4mol L^-1 hydrochloric acid is added to 105 mL of 1.75 × 10^-4 mol L^-1 Mg(OH) ₂,the resulting solution will be:

What reagent could not be used to separate Br^- from CO₃^2- when added to an aqueous solution containing both?

Which of the following compounds is an Arrhenius base?

How many millilitres of 0.550 mol L^-1 hydriodic acid are needed to react with 15.00 mL of 0.217 mol L^-1 CsOH? HI(aq) + CsOH(aq) → CsI(aq) + H₂O(l)

Which of the following compounds is an Arrhenius base?

Which of the compounds of H₂C₂O_4, Ca(OH) ₂,KOH,and HI behave as acids when they are dissolved in water?

Which one of the following compounds behaves as an acid when dissolved in water?

A solution is prepared by mixing 50.0 mL of 0.100 mol L^-1 HCl and 10.0 mL of 0.200 mol L^-1 NaCl.What is the molarity of chloride ion in this solution?

Quiz 5: Introduction to Reactions in Aqueous Solutions

Which of the compounds H2C2O4,Ca(OH) 2,KOH,and HI behave as bases when they are dissolved in water?

In an acid-base neutralization reaction,38.74 mL of 0.500 mol L-1 potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H2SO4 solution?

Which pair of compounds is soluble in water?

What reagent could be used to separate Br- from CH3CO2- when added to an aqueous solution containing both?

The mixing of which pair of reactants will result in a precipitation reaction?

The mixing of which pair of reactants will result in a precipitation reaction?

Which of the following compounds is an Arrhenius base?

According to the balanced equation shown below,4.00 moles of oxalic acid,H2C2O4,reacts with ________ moles of permanganate,MnO4-. 5 H2C2O4(aq) + 2 MnO4-(aq) + 6 H+(aq) → 10 CO2(g) + Mn2+(aq) + 8 H2O(l)

When dissolved in water,KOH behaves as:

Identify the coefficient of Ca(OH) 2(aq) when the following reaction is balanced,and determine the number of millilitres of 0.00300 mol L-1 phosphoric acid required to neutralize 45.00 mL of 0.00150 mol L-1 calcium hydroxide. (unbalanced) Ca(OH) 2(aq) + H3PO4(aq) → Ca3(PO4) 2(aq) + H2O(l)

When 280 mL of 1.50 × 10-4 mol L-1 hydrochloric acid is added to 105 mL of 1.75 × 10-4 mol L-1 Mg(OH) 2,the resulting solution will be:

What reagent could not be used to separate Br- from CO32- when added to an aqueous solution containing both?

Which of the following compounds is an Arrhenius base?

How many millilitres of 0.550 mol L-1 hydriodic acid are needed to react with 15.00 mL of 0.217 mol L-1 CsOH? HI(aq) + CsOH(aq) → CsI(aq) + H2O(l)

Which of the following compounds is an Arrhenius base?

Which of the compounds of H2C2O4, Ca(OH) 2,KOH,and HI behave as acids when they are dissolved in water?

Which one of the following compounds behaves as an acid when dissolved in water?

A solution is prepared by mixing 50.0 mL of 0.100 mol L-1 HCl and 10.0 mL of 0.200 mol L-1 NaCl.What is the molarity of chloride ion in this solution?

Which of the compounds H₂C₂O₄,Ca(OH) ₂,KOH,and HI behave as bases when they are dissolved in water?

In an acid-base neutralization reaction,38.74 mL of 0.500 mol L^-1 potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H₂SO₄ solution?

What reagent could be used to separate Br^- from CH₃CO₂^-when added to an aqueous solution containing both?

According to the balanced equation shown below,4.00 moles of oxalic acid,H₂C₂O₄,reacts with ________ moles of permanganate,MnO₄^-. 5 H₂C₂O₄(aq) + 2 MnO₄^-(aq) + 6 H⁺^(aq) → 10 CO₂(g) + Mn²⁺(aq) + 8 H₂O(l)

When 280 mL of 1.50 × 10^-4mol L^-1 hydrochloric acid is added to 105 mL of 1.75 × 10^-4 mol L^-1 Mg(OH) ₂,the resulting solution will be:

What reagent could not be used to separate Br^- from CO₃^2- when added to an aqueous solution containing both?

How many millilitres of 0.550 mol L^-1 hydriodic acid are needed to react with 15.00 mL of 0.217 mol L^-1 CsOH? HI(aq) + CsOH(aq) → CsI(aq) + H₂O(l)

Which of the compounds of H₂C₂O_4, Ca(OH) ₂,KOH,and HI behave as acids when they are dissolved in water?

A solution is prepared by mixing 50.0 mL of 0.100 mol L^-1 HCl and 10.0 mL of 0.200 mol L^-1 NaCl.What is the molarity of chloride ion in this solution?