Q: A nurse needs to prepare 250 mL of a 0.45% (m/v) NaCl solution. How many grams of NaCl are required?

$$0.45\ \text{g} \times 250\ \text{mL} / 100\ \text{mL} = 1.125\ \text{g}$$

Q: Which formula is used to calculate pH from hydronium ion concentration?

$$\text{pH} = -\log[\text{H}_3\text{O}^+]$$

Q: A solution has a pH of 5. What is the hydronium ion concentration?

$$[\text{H}_3\text{O}^+] = 10$$^{-5}$$\ \text{M}$$

Question 1

Which of the following best describes a solution?

Accepted Answer

A homogeneous mixture of two or more substances where the solute is uniformly distributed within the solvent.

Question 2

A nurse needs to prepare 250 mL of a 0.45% (m/v) NaCl solution. How many grams of NaCl are required?

Accepted Answer

$$0.45\ 	ext{g} 	imes 250\ 	ext{mL} / 100\ 	ext{mL} = 1.125\ 	ext{g}$$

Question 3

Which equation is used to calculate the concentration after dilution?

Accepted Answer

$$C_1V_1 = C_2V_2$$

Question 4

Which of the following best differentiates a solution, colloid, and suspension?

Accepted Answer

Solution particles are molecular-sized and do not scatter light; colloid particles are larger and scatter light (Tyndall effect); suspension particles are largest and settle out.

Question 5

What happens to red blood cells when placed in a hypertonic solution?

Accepted Answer

They lose water and shrink (crenate).

Question 6

Which of the following statements about osmosis is correct?

Accepted Answer

Osmosis is the movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration.

Question 7

Which of the following substances is most likely to dissolve in water?

Accepted Answer

CH$$_3F$$, because it is polar and can form hydrogen bonds with water.

Question 8

Which of the following is a strong electrolyte?

Accepted Answer

NaCl, because it completely dissociates in water.

Question 9

What does equilibrium mean in a chemical process?

Accepted Answer

The rates of the forward and reverse reactions are equal, and concentrations of reactants and products remain constant.

Question 10

Which formula is used to calculate pH from hydronium ion concentration?

Accepted Answer

$$	ext{pH} = -\log[	ext{H}_3	ext{O}^+]$$

Question 11

A solution has a pH of 5. What is the hydronium ion concentration?

Accepted Answer

$$[	ext{H}_3	ext{O}^+] = 10$$^{-5}$$\ 	ext{M}$$

Question 12

Which pair represents an acid and its conjugate base?

Accepted Answer

H$$_2PO$_4^-$$ and HPO$$_4$$^{2-}$$

Question 13

What is the dissociation reaction for NaCl in water?

Accepted Answer

$$	ext{NaCl} ightarrow 	ext{Na}^+ + 	ext{Cl}^-$$

Question 14

How many mEq/L of Na$$^+$$ are in a 0.1 M NaCl solution?

Accepted Answer

$$0.1\ 	ext{mol/L} 	imes 1\ 	ext{eq/mol} 	imes 1000 = 100\ 	ext{mEq/L}$$

Question 15

Which intermolecular force is strongest between CH$$_3F $$and water?

Accepted Answer

Hydrogen bonding

Question 16

Which statement best explains why CCl$$_4 is $$insoluble in water?

Accepted Answer

CCl$$_4 is $$nonpolar and water is polar; 'like dissolves like' does not apply.

Question 17

Which equation represents the neutralization reaction between HCl and NaOH?

Accepted Answer

$$	ext{HCl} + 	ext{NaOH} ightarrow 	ext{NaCl} + 	ext{H}_2	ext{O}$$

Question 18

How would you prepare 450 mL of a 50 mM NaCl solution?

Accepted Answer

Dissolve $$0.050\ 	ext{mol/L} 	imes 0.450\ 	ext{L} = 0.0225\ 	ext{mol}$$ NaCl in 450 mL water.

Question 19

If you take 15.0 mL of a 50 mM NaCl solution and dilute it with 45.0 mL of water, what is the new concentration?

Accepted Answer

$$C_2$$ = \frac{C_1V_1}{$$V_2$$} = \frac{50\ 	ext{mM} 	imes 15.0\ 	ext{mL}}{60.0\ 	ext{mL}} = 12.5\ 	ext{mM}$$

Question 20

Which equation shows the buffer action of H$$_2PO$_4^- / $$HPO$$_4$$^{2-}$$ when an acid is added?

Accepted Answer

$$	ext{HPO}_4$$^{2-}$$ + 	ext{H}^+ ightarrow 	ext{H}_2	ext{PO}_4^-$$

Comprehensive Study Guide: Solutions, Acids & Bases, and Hydrocarbons

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