Q: How many molecules of sucrose ($$\mathrm{C$$_{12}$$H_{22}O$$_{11}}$$, molar mass = 342.30$$\ \mathrm{g/mol}$$) are present in 14.3 mL of a 0.140$$\ \mathrm{M}$ sucrose solution?

$$1.21 \times 10$$^{21}$$ molecules

Question 1

A student dissolves 468 mg of MgI$$_2 in $$enough water to make 50.0 mL of solution. What is the molarity of the solution?

$$	ext{Molar mass of MgI}_2 = 278.11\ 	ext{g/mol}$$

Accepted Answer

$$0.0337\ 	ext{M}$$

Question 2

How many molecules of sucrose ($$\mathrm{C$$_{12}$$H_{22}O$$_{11}}$$, molar mass = 342.30$$\ \mathrm{g/mol}$$) are present in 14.3 mL of a 0.140$$\ \mathrm{M}$ sucrose solution?

Accepted Answer

$$1.21 	imes 10$$^{21}$$ molecules

Question 3

A laboratory technician dilutes 25.0 mL of a $$0.188\ \mathrm{M} Ca(NO$_3$$)$$_2$$ solution to a final volume of 1500.0 mL. What is the final concentration?

Accepted Answer

$$0.00313\ \mathrm{M}$$

Question 4

When aqueous solutions of which pair will form a precipitate upon mixing?

Accepted Answer

NiBr$$_2$$ and AgNO$$_3$$

Question 5

Which ions are spectator ions when aqueous solutions of BaI$$_2$$ and Na$$_2SO$_4$$ are mixed, forming a precipitate of BaSO$$_4$$?

Accepted Answer

Na$$^+$$ and I$$^-$$

Question 6

Which of the following is a weak electrolyte?

Accepted Answer

HF

Question 7

Which of the following combinations contains only weak electrolytes?

Accepted Answer

HF, NH$$_3$$

Question 8

Consider the reaction:

$$\mathrm{C_3H_5O_3 (aq) + O_2$ (g) \rightarrow CO_2$ (g) + H_2O (g)}$$

How many moles of water are produced when 3 moles of C$$_3H$_5O$_3$$ react completely?

Accepted Answer

3

Question 9

Which of the following is paired incorrectly?

Accepted Answer

HNO$$_3$$ – weak acid

Question 10

A patient is given an intravenous solution containing NaCl. Which property of NaCl makes it suitable for this use?

Accepted Answer

It is a strong electrolyte and dissociates completely in water.

Question 11

Which of the following best describes the role of spectator ions in a precipitation reaction?

Accepted Answer

They do not participate in the formation of the precipitate and remain unchanged in solution.

Question 12

A solution is prepared by dissolving 0.50 mol of Na$$_2SO$_4 in $$enough water to make 1.0 L of solution. What is the concentration of Na$$^+$$ ions in the solution?

Accepted Answer

$$1.0\ \mathrm{mol/L}$$

Question 13

Which of the following will NOT produce a precipitate when mixed?

Accepted Answer

KNO$$_3$$ and NaCl

Question 14

A chemist needs to prepare 250 mL of 0.100 M KCl solution. How many grams of KCl are required?

$$	ext{Molar mass of KCl} = 74.55\ 	ext{g/mol}$$

Accepted Answer

$$1.86\ 	ext{g}$$

Question 15

Which of the following statements about strong acids is correct?

Accepted Answer

They ionize completely in aqueous solution.

Question 16

A solution contains 0.20 M HNO$$_3$$ and 0.10 M HF. Which statement is true about the electrical conductivity of the solution?

Accepted Answer

It will be high because HNO$$_3 is a $$strong acid and HF is a weak acid.

Question 17

Which of the following is a correct net ionic equation for the reaction between AgNO$$_3$$ and NaCl in aqueous solution?

Accepted Answer

$$\mathrm{Ag^+ (aq) + Cl^- (aq) \rightarrow AgCl (s)}$$

Question 18

A student mixes solutions of Li$$_2S $$and Cu(NO$$_3$$)$$_2. $$What is the precipitate formed?

Accepted Answer

CuS

Question 19

Which of the following is a characteristic of weak bases?

Accepted Answer

They partially ionize in water.

Solutions, Electrolytes, and Precipitation Reactions: General Chemistry Study Notes

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