Chapter Questions
Of the following substances, which ones are generally soluble in water? (See Figure $14.2$ or Appendix V.)(a) $\mathrm{AgCl}$(d) $\mathrm{NaOH}$(b) $\mathrm{K}_{2} \mathrm{SO}_{4}$(e) $\mathrm{PbI}_{2}$(c) $\mathrm{Na}_{3} \mathrm{PO}_{4}$(f) $\mathrm{SnCO}_{3}$
Of the following substances, which ones are generally soluble in water? (See Figure $14.2$ or Appendix V.)(a) $\mathrm{Ba}_{3}\left(\mathrm{PO}_{4}\right)_{2}$(d) $\mathrm{NH}_{4} \mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$(b) $\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}$(e) $\mathrm{MgO}$(c) $\mathrm{Fe}(\mathrm{OH})_{3}$(f) $\mathrm{AgNO}_{3}$
Calculate the mass percent of the following solutions:(a) $15.0 \mathrm{~g} \mathrm{KCl}+100.0 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}$(b) $2.50 \mathrm{~g} \mathrm{Na}_{3} \mathrm{PO}_{4}+10.0 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}$(c) $0.20 \mathrm{~mol} \mathrm{NH}{ }_{4} \mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}+125 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}$(d) $1.50 \mathrm{~mol} \mathrm{NaOH}$ in $33.0 \mathrm{~mol} \mathrm{} \mathrm{H}_{2} \mathrm{O}$
Calculate the mass percent of the following solutions:(a) $25.0 \mathrm{~g} \mathrm{NaNO}_{3}$ in $125.0 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}$(b) $1.25 \mathrm{~g} \mathrm{CaCl}_{2}$ in $35.0 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}$(c) $0.75 \mathrm{~mol} \mathrm{~K} \mathrm{KrO}_{4}$ in $225 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}$(d) $1.20 \mathrm{~mol} \mathrm{H}_{2} \mathrm{SO}_{4}$ in $72.5 \mathrm{~mol} \mathrm{H}_{2} \mathrm{O}$
A chemistry lab experiment requires $25.2 \mathrm{~g}$ of silver nitrate. How many grams of a $15.5 \%$ by mass solution of silver nitrate should be used?
A reaction requires $25.0 \mathrm{~g}$ of sodium chloride. How many grams of a $10.0 \%$ by mass solution would provide this amount of solute?
In $25 \mathrm{~g}$ of a $7.5 \%$ by mass solution of $\mathrm{CaSO}_{4}$(a) how many grams of solute are present?(b) how many grams of solvent are present?
In $75 \mathrm{~g}$ of a $12.0 \%$ by mass solution of $\mathrm{BaCl}_{2}$(a) how many grams of solute are present?(b) how many grams of solvent are present?
Determine the mass/volume percent of a solution made by dissolving:(a) $15.0 \mathrm{~g}$ of $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$ (ethanol) in water to make $150.0 \mathrm{~mL}$ of solution(b) $25.2 \mathrm{~g}$ of $\mathrm{NaCl}$ in water to make $125.5 \mathrm{~mL}$ of solution
Determine the mass/volume percent of a solution made by dissolving:(a) $175.2 \mathrm{~g}$ of table sugar, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$, in water to make $275.5 \mathrm{~mL}$ of solution(b) $35.5 \mathrm{~g}$ of $\mathrm{CH}_{3} \mathrm{OH}$ (methanol) in water to make $75.0 \mathrm{~mL}$ of solution
Determine the volume percent of a solution made by dissolving:(a) $50.0 \mathrm{~mL}$ of hexanol in enough ethanol to make $125 \mathrm{~mL}$ of solution(b) $2.0 \mathrm{~mL}$ of ethanol in enough methanol to make $15.0 \mathrm{~mL}$ of solution
Determine the volume percent of a solution made by dissolving:(a) $37.5 \mathrm{~mL}$ of butanol in enough ethanol to make $275 \mathrm{~mL}$ of solution(b) $4.0 \mathrm{~mL}$ of methanol in enough water to make $25.0 \mathrm{ml}$ of solution
Calculate the molarity of the following solutions:(a) $0.25 \mathrm{~mol}$ of solute in $75.0 \mathrm{~mL}$ of solution(b) $1.75 \mathrm{~mol}$ of $\mathrm{KBr}$ in $0.75 \mathrm{~L}$ of solution(c) $35.0 \mathrm{~g}$ of $\mathrm{NaC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$ in $1.25 \mathrm{~L}$ of solution(d) $75 \mathrm{~g}$ of $\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}$ in $1.0 \mathrm{~L}$ of solution
Calculate the molarity of the following solutions:(a) $0.50 \mathrm{~mol}$ of solute in $125 \mathrm{~mL}$ of solution(b) $2.25 \mathrm{~mol}$ of $\mathrm{CaCl}_{2}$ in $1.50 \mathrm{~L}$ of solution(c) $275 \mathrm{~g} \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$ in $775 \mathrm{~mL}$ of solution(d) $125 \mathrm{~g} \mathrm{MgSO}_{4} \cdot 7 \mathrm{H}_{2} \mathrm{O}$ in $2.50 \mathrm{~L}$ of solution
Calculate the number of moles of solute in each of the following solutions:(a) $1.5 \mathrm{~L}$ of $1.20 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$(b) $25.0 \mathrm{~mL}$ of $0.0015 \mathrm{M} \mathrm{BaCl}_{2}$(c) $125 \mathrm{~mL}$ of $0.35 \mathrm{M} \mathrm{K}_{3} \mathrm{PO}_{4}$
Calculate the number of moles of solute in each of the following solutions:(a) $0.75 \mathrm{~L}$ of $1.50 \mathrm{M} \mathrm{HNO}_{3}$(b) $10.0 \mathrm{~mL}$ of $0.75 \mathrm{M} \mathrm{NaClO}_{3}$(c) $175 \mathrm{~mL}$ of $0.50 \mathrm{M} \mathrm{LiBr}$
Calculate the grams of solute in each of the following solutions:(a) $2.5 \mathrm{~L}$ of $0.75 \mathrm{M} \mathrm{K}_{2} \mathrm{CrO}_{4}$(b) $75.2 \mathrm{~mL}$ of $0.050 \mathrm{M} \mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$(c) $250 \mathrm{~mL}$ of $16 \mathrm{M} \mathrm{HNO}_{3}$
Calculate the grams of solute in each of the following solutions:(a) $1.20 \mathrm{~L}$ of $18 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$(b) $27.5 \mathrm{~mL}$ of $1.50 \mathrm{M} \mathrm{KMnO} 4$(c) $120 \mathrm{~mL}$ of $0.025 \mathrm{M} \mathrm{Fe} \mathrm{Fe}_{4}\left(\mathrm{SO}_{3}\right.$
How many milliliters of $0.750 \mathrm{M} \mathrm{H}_{3} \mathrm{PO}_{4}$ will contain the following?(a) $0.15 \mathrm{~mol} \mathrm{H}_{3} \mathrm{PO}_{4}$(b) $35.5 \mathrm{~g} \mathrm{H}_{3} \mathrm{PO}_{4}$
How many milliliters of $0.250 \mathrm{M} \mathrm{NH}_{4} \mathrm{Cl}$ will contain the following?(a) $0.85 \mathrm{~mol} \mathrm{NH}_{4} \mathrm{Cl}$(b) $25.2 \mathrm{~g} \mathrm{NH}_{4} \mathrm{Cl}$
What will be the molarity of the resulting solutions made by mixing the following? Assume that volumes are additive.(a) $125 \mathrm{~mL}$ of $5.0 \mathrm{M} \mathrm{H}_{3} \mathrm{PO}_{4}$ with $775 \mathrm{~mL}^{2}$ of $\mathrm{H}_{2} \mathrm{O}$(b) $250 \mathrm{~mL}$ of $0.25 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}$ with $750 \mathrm{~mL}$ of $\mathrm{H}_{2} \mathrm{O}$(c) $75 \mathrm{~mL}$ of $0.50 \mathrm{M} \mathrm{HNO}_{3}$ with $75 \mathrm{~mL}$ of $1.5 \mathrm{M} \mathrm{HNO}_{3}$
What will be the molarity of the resulting solutions made by mixing the following? Assume that volumes are additive.(a) $175 \mathrm{~mL}$ of $3.0 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$ with $275 \mathrm{~mL}_{2}$ of $\mathrm{H}_{2} \mathrm{O}$(b) $350 \mathrm{~mL}$ of $0.10 \mathrm{M} \mathrm{CuSO}_{4}$ with $150 \mathrm{~mL}$ of $\mathrm{H}_{2} \mathrm{O}$(c) $50.0 \mathrm{~mL}$ of $0.250 \mathrm{M} \mathrm{HCl}$ with $25.0 \mathrm{~mL}$ of $0.500 \mathrm{M} \mathrm{HCl}$
Calculate the volume of concentrated reagent required to prepare the diluted solutions indicated:(a) $15 \mathrm{M} \mathrm{H}_{3} \mathrm{PO}_{4}$ to prepare $750 \mathrm{~mL}$ of $3.0 \mathrm{M} \mathrm{H}_{3} \mathrm{PO}_{4}$(b) $16 \mathrm{M} \mathrm{HNO}_{3}$ to prepare $250 \mathrm{~mL}$ of $0.50 \mathrm{M} \mathrm{HNO}_{3}$
Calculate the volume of concentrated reagent required to prepare the diluted solutions indicated:(a) $18 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$ to prepare $225 \mathrm{~mL}$ of $2.0 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$(b) $15 \mathrm{M} \mathrm{NH}_{3}$ to prepare $75 \mathrm{~mL}$ of $1.0 \mathrm{M} \mathrm{NH}_{3}$
Calculate the molarity of the solutions made by mixing $125 \mathrm{~mL}$ of $6.0 \mathrm{M} \mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$ with the following:(a) $525 \mathrm{~mL}$ of $\mathrm{H}_{2} \mathrm{O}$(b) $175 \mathrm{~mL}$ of $1.5 \mathrm{M} \mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$
Calculate the molarity of the solutions made by mixing $175 \mathrm{~mL}$ of $3.0 \mathrm{M} \mathrm{HCl}$ with the following:(a) $250 \mathrm{~mL}$ of $\mathrm{H}_{2} \mathrm{O}$(b) $115 \mathrm{~mL}$ of $6.0 \mathrm{M} \mathrm{HCl}$
Use the equation to calculate the following:$$\begin{aligned}3 \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}(a q)+2 \mathrm{Na}_{3} \mathrm{PO}_{4}(a q) \rightarrow \\\mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}(s)+6 \mathrm{NaNO}_{3}(a q)\end{aligned}$$(a) the moles $\mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}$ produced from $2.7 \mathrm{~mol} \mathrm{Na} \mathrm{PO}_{4}$(b) the moles $\mathrm{NaNO}_{3}$ produced from $0.75 \mathrm{~mol} \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$(c) the moles $\mathrm{Na}_{3} \mathrm{PO}_{4}$ required to react with $1.45 \mathrm{~L}$ of $0.225 \mathrm{M} \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$(d) the grams of $\mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}$ that can be obtained from $125 \mathrm{~mL}$ of $0.500 \mathrm{M} \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$(e) the volume of $0.25 \mathrm{M} \mathrm{Na} \mathrm{NO}_{4}$ needed to react with $15.0 \mathrm{~mL}$ of $0.50 \mathrm{M} \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$(f) the molarity $(M)$ of the $\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$ solution when $50.0 \mathrm{~mL}$ react with $50.0 \mathrm{~mL}$ of $2.0 \mathrm{M} \mathrm{Na}_{3} \mathrm{PO}_{4}$
Use the equation to calculate the following.$2 \mathrm{NaOH}(a q)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \rightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}(a q)+2 \mathrm{H}_{2} \mathrm{O}(l)$(a) the moles $\mathrm{Na}_{2} \mathrm{SO}_{4}$ produced from $3.6 \mathrm{~mol} \mathrm{} \mathrm{H}_{2} \mathrm{SO}_{4}$(b) the moles $\mathrm{H}_{2} \mathrm{O}$ produced from $0.025 \mathrm{~mol} \mathrm{NaOH}$(c) the moles $\mathrm{NaOH}$ required to react with $2.50 \mathrm{~L}$ of $0.125 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$(d) the grams of $\mathrm{Na}_{2} \mathrm{SO}_{4}$ that can be obtained from $25 \mathrm{~mL}$ of $0.050 \mathrm{M} \mathrm{NaOH}$(e) the volume of $0.250 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$ needed to react with $25.5 \mathrm{~mL}$ of $0.750 \mathrm{M} \mathrm{NaOH}$(f) the molarity $(M)$ of the $\mathrm{NaOH}$ solution when $48.20 \mathrm{~mL}$ react with $35.72 \mathrm{~mL}$ of $0.125 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$
Use the equation to calculate the following:$2 \mathrm{KMnO}_{4}(a q)+16 \mathrm{HCl}(a q) \rightarrow$$$2 \mathrm{MnCl}_{2}(a q)+5 \mathrm{Cl}_{2}(g)+8 \mathrm{H}_{2} \mathrm{O}(l)+2 \mathrm{KCl}(a q)$$(a) the moles of $\mathrm{H}_{2} \mathrm{O}$ that can be obtained from$15.0 \mathrm{~mL}$ of $0.250 \mathrm{M} \mathrm{HCl}$(b) the volume of $0.150 \mathrm{M} \mathrm{KMnO}{ }_{4}$ needed to produce $1.85 \mathrm{~mol} \mathrm{MnCl} 2$(c) the volume of $2.50 \mathrm{M} \mathrm{HCl}$ needed to produce $125 \mathrm{~mL}$ of $0.525 \mathrm{M} \mathrm{KCl}$(d) the molarity $(M)$ of the $\mathrm{HCl}$ solution when $22.20 \mathrm{~mL}$ react with $15.60 \mathrm{~mL}$ of $0.250 \mathrm{M} \mathrm{KMnO}_{4}$(e) the liters of $\mathrm{Cl}_{2}$ gas at STP produced by the reaction of $125 \mathrm{~mL}$ of $2.5 \mathrm{M} \mathrm{HCl}$(f) the liters of $\mathrm{Cl}_{2}$ gas at STP produced by the reaction of $15.0 \mathrm{~mL}$ of $0.750 \mathrm{M} \mathrm{HCl}$ and $12.0 \mathrm{~mL}$ of $0.550 \mathrm{M}$ $\mathrm{KMnO}_{4}$
Use the equation to calculate the following:$$\begin{aligned}\mathrm{K}_{2} \mathrm{CO}_{3}(a q)+2 \mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}(a q) & \rightarrow \\& 2 \mathrm{KC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}(a q)+\mathrm{H}_{2} \mathrm{O}(l)+\mathrm{CO}_{2}(g)\end{aligned}$$(a) the moles of $\mathrm{H}_{2} \mathrm{O}$ that can be obtained from $25.0 \mathrm{~mL}$ of $0.150 \mathrm{M} \mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$(b) the volume of $0.210 \mathrm{M} \mathrm{K}_{2} \mathrm{CO}_{3}$ needed to produce $17.5 \mathrm{~mol} \mathrm{KC} \mathrm{K}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$(c) the volume of $1.25 \mathrm{M} \mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$ needed to react with $75.2 \mathrm{~mL} 0.750 \mathrm{M} \mathrm{K}_{2} \mathrm{CO}_{3}$(d) the molarity (M) of the $\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$ solution when$10.15 \mathrm{~mL}$ react with $18.50 \mathrm{~mL}$ of $0.250 \mathrm{M} \mathrm{K}_{2} \mathrm{CO}_{3}$(e) the liters of $\mathrm{CO}_{2}$ gas at STP produced by the reaction of $105 \mathrm{~mL}$ of $1.5 \mathrm{M} \mathrm{HC} \mathrm{H}_{3} \mathrm{O}_{2}$(f) the liters of $\mathrm{CO}_{2}$ gas at STP produced by the reaction of $25.0 \mathrm{~mL}$ of $0.350 \mathrm{M} \mathrm{K}_{2} \mathrm{CO}_{3}$ and $25.0 \mathrm{~mL}$ of $0.250 \mathrm{M}$ $\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}$
Calculate the molality of each of the following solutions:(a) $2.0 \mathrm{~mol} \mathrm{HCl}$ in $175 \mathrm{~g}$ water(b) $14.5 \mathrm{~g} \mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$ in $550.0 \mathrm{~g}$ water(c) $25.2 \mathrm{~mL}$ methanol, $\mathrm{CH}_{3} \mathrm{OH}(d=0.791 \mathrm{~g} / \mathrm{mL})$ in $595 \mathrm{~g}$ ethanol, $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}$
Calculate the molality of each of the following solutions:(a) $1.25 \mathrm{~mol} \mathrm{CaCl}$ in $750.0 \mathrm{~g}$ water(b) $2.5 \mathrm{~g} \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$ in $525 \mathrm{~g}$ water(c) $17.5 \mathrm{~mL}$ 2-propanol, $\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHOH}(d=0.785 \mathrm{~g} / \mathrm{mL})$ in $35.5 \mathrm{~mL} \mathrm{} \mathrm{H}_{2} \mathrm{O}(d=1.00 \mathrm{~g} / \mathrm{mL})$
What is the (a) molality, (b) freezing point, and (c) boiling point of a solution containing $2.68 \mathrm{~g}$ of naphthalene $\left(\mathrm{C}_{10} \mathrm{H}_{8}\right)$ in $38.4 \mathrm{~g}$ of benzene $\left(\mathrm{C}_{6} \mathrm{H}_{6}\right)$ ?
What is the (a) molality, (b) freezing point, and (c) boiling point of a solution containing $100.0 \mathrm{~g}$ of ethylene glycol $\left(\mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}_{2}\right)$ in $150.0 \mathrm{~g}$ of water?
The freezing point of a solution of $8.00 \mathrm{~g}$ of an unknown compound dissolved in $60.0 \mathrm{~g}$ of acetic acid is $13.2^{\circ} \mathrm{C}$. Calculate the molar mass of the compound.
What is the molar mass of a compound if $4.80 \mathrm{~g}$ of the compound dissolved in $22.0 \mathrm{~g}$ of $\mathrm{H}_{2} \mathrm{O}$ given a solution that freezes at $-2.50^{\circ} \mathrm{C}$ ?
What happens to salt $(\mathrm{NaCl})$ crystals when they are dissolved in water?
What happens to sugar molecules $\left(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\right)$ when they are dissolved in water?
Why do sugar and salt behave differently when dissolved in water?
Why don't blood cells shrink or swell in an isotonic sodium chloride solution ( $0.9 \%$ saline)?
In the picture of dissolving $\mathrm{KMnO}_{4}$ found in Section 14.1, the compound is forming purple streaks as it dissolves. Why?
In Figure 14.4, observe the line for $\mathrm{KNO}_{3}$. Explain why it slopes up from left to right. How does the slope compare to the slopes of the other substances? What does this mean?
An oral rehydration fluid contains $13.5$ g glucose, $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$, per liter of solution. What is the molarity of glucose in this solution?
How many grams of solution, $10.0 \% \mathrm{NaOH}$ by mass, are required to neutralize $250.0 \mathrm{~g}$ of a $1.0 \mathrm{~m}$ solution of $\mathrm{HCl}$ ?
A sugar syrup solution contains $15.0 \%$ sugar, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$, by mass and has a density of $1.06 \mathrm{~g} / \mathrm{mL}$.(a) How many grams of sugar are in $1.0 \mathrm{~L}$ of this syrup?(b) What is the molarity of this solution?(c) What is the molality of this solution?
A solution of $3.84 \mathrm{~g} \mathrm{C}_{4} \mathrm{H}_{2} \mathrm{~N}$ (empirical formula) in $250.0 \mathrm{~g}$ of benzene depresses the freezing point of benzene $0.614^{\circ} \mathrm{C}$. What is the molecular formula for the compound?
Hydrochloric acid $(\mathrm{HCl})$ is sold as a concentrated aqueous solution $(12.0 \mathrm{~mol} / \mathrm{L})$. If the density of the solution is $1.18 \mathrm{~g} / \mathrm{mL}$, determine the molality of the solution.
How many grams of $\mathrm{KNO}_{3}$ are needed to make $450 \mathrm{~mL}$ of a solution that is to contain $5.5 \mathrm{mg} / \mathrm{mL}$ of potassium ion? Calculate the molarity of the solution.
Witch hazel solution, an astringent for skin, contains $14 \%$ ethyl alcohol, $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$, by volume. How many $\mathrm{mL}$ of ethyl alcohol are contained in a 16 fluid ounce bottle of witch hazel?
Given a solution containing $16.10 \mathrm{~g} \mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}_{2}$ in $82.0 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}$ that has a boiling point of $101.62^{\circ} \mathrm{C}$, verify that the boiling point elevation constant $\mathrm{K}_{f}$ for water is $0.512^{\circ} \mathrm{C} \mathrm{kg} \mathrm{H} \mathrm{H}_{2} \mathrm{O} / \mathrm{mole}$ solute.
Physiological saline $(\mathrm{NaCl})$ solutions used in intravenous injections have a concentration of $0.90 \% \mathrm{NaCl}$ (mass/volume).(a) How many grams of $\mathrm{NaCl}$ are needed to prepare $500.0 \mathrm{~mL}$ of this solution?(b) How much water must evaporate from this solution to give a solution that is $9.0 \% \mathrm{NaCl}$ (mass/volume)?
A solution is made from $50.0 \mathrm{~g} \mathrm{KNO}_{3}$ and $175 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}$. How many grams of water must evaporate to give a saturated solution of $\mathrm{KNO}_{3}$ in water at $20^{\circ} \mathrm{C}$ ? (See Figure 14.4.)
What volume of $70.0 \%$ rubbing alcohol can you prepare if you have only $150 \mathrm{~mL}$ of pure isopropyl alcohol on hand?
At $20^{\circ} \mathrm{C}$, an aqueous solution of $\mathrm{HNO}_{3}$ that is $35.0 \% \mathrm{HNO}_{3}$ by mass has a density of $1.21 \mathrm{~g} / \mathrm{mL}$.(a) How many grams of $\mathrm{HNO}_{3}$ are present in $1.00 \mathrm{~L}$ of this solution?(b) What volume of this solution will contain $500 . \mathrm{g} \mathrm{HNO}_{3}$ ?
What is the molarity of a phosphoric acid solution if the solution is $85 \%$ by mass $\mathrm{H}_{3} \mathrm{PO}_{4}$ and has a density of $1.7 \mathrm{~g} / \mathrm{mL}$ ?
To what volume must a solution of $80.0 \mathrm{~g} \mathrm{H}_{2} \mathrm{SO}_{4}$ in $500.0 \mathrm{~mL}$ of solution be diluted to give a $0.10 \mathrm{M}$ solution?
How many grams of ethylene glycol, $\mathrm{HOCH}_{2} \mathrm{CH}_{2} \mathrm{OH}$, are present in $4.0$ gallons of a $5.25 \mathrm{M}$ solution?
(a) How many moles of hydrogen will be liberated from $200.0 \mathrm{~mL}$ of $3.00 \mathrm{M} \mathrm{HCl}$ reacting with an excess of magnesium? The equation is$$\mathrm{Mg}(s)+2 \mathrm{HCl}(a q) \longrightarrow \mathrm{MgCl}_{2}(a q)+\mathrm{H}_{2}(g)$$(b) How many liters of hydrogen gas $\left(\mathrm{H}_{2}\right)$ measured at $27^{\circ} \mathrm{C}$ and 720 torr will be obtained?(Hint: Use the ideal gas law.)
Which will be more effective in neutralizing stomach acid, $\mathrm{HCl}$ : a tablet containing $1.20 \mathrm{~g} \mathrm{Mg}(\mathrm{OH})_{2}$ or a tablet containing $1.00 \mathrm{~g} \mathrm{Al}(\mathrm{OH})_{3}$ ? Show evidence for your answer.
Which would be more effective as an antifreeze in an automobile radiator? A solution containing(a) $10 \mathrm{~kg}$ of methyl alcohol $\left(\mathrm{CH}_{3} \mathrm{OH}\right)$ or $10 \mathrm{~kg}$ of ethyl alcohol $\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right)$ ?(b) $10 \mathrm{~m}$ solution of methyl alcohol or $10 \mathrm{~m}$ solution of ethyl alcohol?
Automobile battery acid is $38 \% \mathrm{H}_{2} \mathrm{SO}_{4}$ and has a density of $1.29 \mathrm{~g} / \mathrm{mL}$. Calculate the molality and the molarity of this solution.
What is the (a) molality and (b) boiling point of an aqueous sugar, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$, solution that freezes at $-5.4^{\circ} \mathrm{C}$ ?
A solution of $6.20 \mathrm{~g} \mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}_{2}$ in water has a freezing point of $-0.372^{\circ} \mathrm{C}$. How many grams of $\mathrm{H}_{2} \mathrm{O}$ are in the solution?
What (a) mass and (b) volume of ethylene glycol $\left(\mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}_{2}\right.$, density $=1.11 \mathrm{~g} / \mathrm{mL}$ ) should be added to $12.0 \mathrm{~L}$ of water in an automobile radiator to protect it from freezing at $-20^{\circ} \mathrm{C}$ ? (c) To what temperature Fahrenheit will the radiator be protected?
If $150 \mathrm{~mL}$ of $0.055 \mathrm{M} \mathrm{HNO}_{3}$ are needed to completely neutralize $1.48 \mathrm{~g}$ of an impure sample of sodium hydrogen carbonate (baking soda), what percent of the sample is baking soda?
(a) How much water must be added to concentrated sulfuric acid $\left(\mathrm{H}_{2} \mathrm{SO}_{4}\right)(17.8 \mathrm{M})$ to prepare $8.4 \mathrm{~L}$ of $1.5 \mathrm{M}$ sulfuric acid solution?(b) How many moles of $\mathrm{H}_{2} \mathrm{SO}_{4}$ are in each milliliter of the original concentrate?(c) How many moles are in each milliliter of the diluted solution?
How would you prepare a $6.00 \mathrm{M} \mathrm{HNO}_{3}$ solution if only $3.00 \mathrm{M}$ and $12.0 \mathrm{M}$ solutions of the acid are available for mixing?
A $20.0-\mathrm{mL}$ portion of an $\mathrm{HBr}$ solution of unknown strength is diluted to exactly $240 \mathrm{~mL}$. If $100.0 \mathrm{~mL}$ of this diluted solution requires $88.4 \mathrm{~mL}$ of $0.37 \mathrm{M} \mathrm{NaOH}$ to achieve complete neutralization, what was the strength of the original $\mathrm{HBr}$ solution?
When $80.5 \mathrm{~mL}$ of $0.642 \mathrm{M} \mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}$ are mixed with $44.5 \mathrm{~mL}$ of $0.743 \mathrm{M} \mathrm{KOH}$, a precipitate of $\mathrm{Ba}(\mathrm{OH})_{2}$ forms. How many grams of $\mathrm{Ba}(\mathrm{OH})_{2}$ do you expect?
A $0.25 \mathrm{M}$ solution of lithium carbonate $\left(\mathrm{Li}_{2} \mathrm{CO}_{3}\right)$, a drug used to treat manic depression, is prepared.(a) How many moles of $\mathrm{Li}_{2} \mathrm{CO}_{3}$ are present in $45.8 \mathrm{~mL}$ of the solution?(b) How many grams of $\mathrm{Li}_{2} \mathrm{CO}_{3}$ are in $750 \mathrm{~mL}$ of the same solution?(c) How many milliliters of the solution would be needed to supply $6.0 \mathrm{~g}$ of the solute?(d) If the solution has a density of $1.22 \mathrm{~g} / \mathrm{mL}$, what is its mass percent?
When solutions of hydrochloric acid and sodium sulfite react, a salt, water, and sulfur dioxide gas are produced. How many liters of sulfur dioxide gas at 775 torr and $22^{\circ} \mathrm{C}$ can be produced when $125 \mathrm{~mL}$ of $2.50 \mathrm{M}$ hydrochloric acid react with $75.0 \mathrm{~mL}$ of $1.75 \mathrm{M}$ sodium sulfite?
Consider a saturated solution at $20^{\circ} \mathrm{C}$ made from $5.549$ moles of water and an unknown solute. You determine the mass of the container containing the solution to be $563 \mathrm{~g}$. The mass of the empty container is $375 \mathrm{~g}$. Identify the solute.