Holt Chemistry
R.Thomas Myers, Keith Oldham,Savatore Tocci
Educators
What happens to a suspension when it is allowed to stand over a period of time?
If sugar is dissolved in water, which component is the solute, and which component is the solvent?
Of the following three substances, which two are miscible with one another: oil, water, and ethanol?
One solution is made by dissolving sucrose in water. Another solution is made by dissolving NaCl in water. Which of these dissolving processes involves dissociation?
What mass of ammonium chloride can be added to 100 g of water at $20^{\circ} \mathrm{C}$ before the solution becomes saturated? (See Figure $12 . )$
If 20 $\mathrm{g} \mathrm{KCl}$ is dissolved in 100 $\mathrm{g}$ of water at $20^{\circ} \mathrm{C},$ is the solution unsaturated, saturated, or supersaturated? (See Figure 12.)
Write a paragraph explaining what happens to an ionic salt in the following steps: it is dissolved in water, more of it than its solubility amount is added to the solution, the solution is heated, the solution is cooled to room temperature, and the solution is disturbed by adding more solute.
What kind of mixture is soap able to form in order to make oil and water soluble?
What are the two components of a solution, and how do they relate to each other?
Explain how distillation can be used to
obtain drinking water from sea water.
Explain how paper chromatography separates the components in a solution.
List these mixtures in order of increasing particle size: muddy water, sugar water, sand in water, and milk.
A few drops of milk are added to a glass of water, producing a cloudy mixture. The water is still cloudy after standing in the refrigerator for a week. What is this mixture called?
Name a unit of concentration commonly used to express small concentrations.
State the following expression in words: $\left[\mathrm{K}_{3} \mathrm{PO}_{4}\right]$
A solution of $\mathrm{NaCl}$ is 1 $\mathrm{M.}$ Why is the concentration of particles 2 $\mathrm{M} ?$
Describe how you would prepare 250.0 $\mathrm{mL}$ of a. 0.500 $\mathrm{M}$ solution of $\mathrm{NaCl}$ by using apparatus found in a chemistry lab.
Why do small solid crystals dissolve in liquid more quickly than large crystals?
Would the compound BaSO $_{4}$ be considered soluble in water?
Would the compound $\mathrm{K}_{2} \mathrm{O}$ be considered soluble in water?
A solution of salt in water conducts electricity, but a solution of sugar does not. Explain why.
A 1 $\mathrm{M}$ solution of $\mathrm{NaCl}$ in water has a freezing point that is $3.7^{\circ} \mathrm{C}$ lower than pure water. Estimate what the freezing point would be for a 1 $\mathrm{M}$ solution of $\mathrm{CaCl}_{2}$ .
Explain why soap is a surfactant, a detergent, and an emulsifying agent.
Explain why acetic acid is considered a weak electrolyte and why HCl is considered a strong electrolyte.
A saturated solution of $\mathrm{PbCO}_{3}$ contains 0.00011 $\mathrm{g} \mathrm{PbCO}_{3}$ in 100 $\mathrm{g}$ of water. What is this concentration in parts per million?
Community water supplies usually contain 1.0 ppm of sodium fluoride. A particular water supply contains 0.0016 $\mathrm{g}$ of NaF in 1.60 $\mathrm{L}$ of water. Does it have enough NaF?
Most community water supplies have 0.5 ppm of chlorine added for purification What mass of chlorine must be added to 100.0 L of water to achieve this level?
A 12.5 kg sample of shark meat contained 22 mg of methyl mercury, $\mathrm{CH}_{3} \mathrm{Hg}^{+} .$ Is this amount within the legal limit of 1.00 ppm of
methyl mercury in meat?
If 15.55 g $\mathrm{NaOH}$ are dissolved in enough water to make a 500.0 $\mathrm{mL}$ solution, what is the molarity of the solution?
A solution contains 32.7 $\mathrm{g} \mathrm{H}_{3} \mathrm{PO}_{4}$ in 455 $\mathrm{mL}$ of solution. Calculate its molarity.
How many moles of $\mathrm{AgNO}_{3}$ are needed to prepare 0.50 $\mathrm{L}$ of a 4.0 $\mathrm{M}$ solution?
What is the molarity of a solution that contains 20.0 g $\mathrm{NaOH}$ in 2.00 $\mathrm{L}$ of solution?
Calculate the molarity of a $\mathrm{H}_{3} \mathrm{PO}_{4}$ solution of 6.66 $\mathrm{g}$ in 555 $\mathrm{mL}$ of solution.
Calculate the mass of $\mathrm{NaOH}$ in 65.0 $\mathrm{mL}$ of 2.25 $\mathrm{M}$ solution.
What mass of $\mathrm{HCl}$ is contained in 645 $\mathrm{mL}$ of 0.266 $\mathrm{M}$ solution?
What is the molarity of a hydrochloric acid solution that contains 18.3 $\mathrm{g} \mathrm{HCl}$ in 100.0 $\mathrm{mL}$ of solution?
A saturated solution of $\mathrm{NaCl}$ contains 36 $\mathrm{g}$ $\mathrm{NaCl}$ in 114 $\mathrm{mL}$ of solution. What is the molarity of the solution?
Calculate the mass of LiF in 100.0 $\mathrm{mL}$ of
0.100 $\mathrm{M}$ solution.
How many grams of glucose, $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6},$ are in 255 $\mathrm{mL}$ of a 3.55 $\mathrm{M}$ solution?
You mix 1.00 $\mathrm{L}$ of 2.00 $\mathrm{M} \mathrm{BaCl}_{2}$ with 1.00 $\mathrm{L}$ of 2.00 $\mathrm{M} \mathrm{AgNO}_{3} .$ What compounds
remain in solution, and what are their concentrations? $$\begin{array}{c}{\mathrm{BaCl}_{2}(a q)+2 \mathrm{AgNO}_{3}(a q) \longrightarrow} \\ {2 \mathrm{AgCl}(s)+\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}(a q)}\end{array}$$
How many milliliters of 18.0 $\mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$ are required to react with 250 $\mathrm{mL}$ of 2.50 $\mathrm{M}$
$\mathrm{Al}(\mathrm{OH})_{3}$ if the products are aluminum sulfate and water?
If 75.0 $\mathrm{mL}$ of an AgNO $_{3}$ solution reacts with enough Cu to produce 0.250 $\mathrm{g}$ Ag by single displacement, what is the molarity of the
initial AgNO $_{3}$ solution if $\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}$ is the other product?
How many milliliters of 1.0 $\mathrm{M} \mathrm{AgNO}_{3}$ are needed to provide 168.88 $\mathrm{g}$ of pure $\mathrm{AgNO}_{3} ?$
What is the mass of potassium chromate, $\mathrm{K}_{2} \mathrm{CrO}_{4},$ in 20.0 $\mathrm{mL}$ of 6.0 M solution?
Sodium ions in blood serum normally are 0.145 $\mathrm{M} .$ How many grams of sodium ions are in 10.0 $\mathrm{mL}$ of serum?
A package of compounds used to achieve rehydration in sick patients contains 20.0 g of glucose, $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$ . When this material is diluted to $1.00 \mathrm{L},$ what is the molarity of glucose?
Calcium phosphate, $\mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2},$ is quite cheap and causes few pollution problems. Why is it not used to de-ice sidewalks? (Hint: See Table 2 in Section 3.)
A calculation shows that a salt will have a negative $\Delta H$ and a positive $\Delta S$ when it dissolves. Is it actually soluble?
Imagine you are a sailor who must wash in sea water. Which is better to use, soap or synthetic detergent? Why?
Air pressure in an airplane cabin while in flight is significantly lower than at sea level. Explain in terms of Henry's law how this affects the speed at which a carbonated beverage, after opening, loses its fizz.
Why would a substance that contains only ionic bonds not work as an emulsifying agent?
Design a solubility experiment that would identify an unknown substance that is either CsCl, RbCl, LiCl, NH $_{4}$ , KCl, or NaCl. (Hint: You will need a solubility versus temperature graph for each of the salts.) If your instructor approves your design, get a sample from the instructor, and perform your experiment.
Many reagent chemicals used in the lab are sold in the form of concentrated aqueous solutions, as shown in the table below. Different volumes are diluted to 1.00 $\mathrm{L}$ to make less-concentrated solutions. Create a computer spreadsheet that will calculate the volume of concentrated reagent needed to make 1.00 L solutions of any molar concentration that you enter.
Use the following terms to create a concept map: concentration, dissociates, electrical conductivity, solute, and solvent. Study the graph below, and answer the questions that follow. For help in interpreting graphs, see Appendix $B$ , "Study Skills for Chemistry."
Are most of the substances represented on the graph more or less soluble at higher temperatures?
Which salt is most soluble at $10^{\circ} \mathrm{C} ?$ at $60^{\circ} \mathrm{C} ?$ at $80^{\circ} \mathrm{C}$ ?
If you heat water to $80^{\circ} \mathrm{C},$ what amount of $\mathrm{NaCl}$ could you dissolve in it as compared to water that is at $20^{\circ} \mathrm{C} ?$
Which salt's solubility is most strongly affected by changes in temperature?
Graphing Calculator Predicting Solubility from Tabular Data The graphing calculator can run a programthat graphs solubility data. Given solubility measurements for KCl, you will use the data to predict its solubility at various temperatures. Go to Appendix C. If you are using a TI-83 Plus, you can download the program and data sets and run the application as directed. Press the APPS key on your calculator, then choose the application CHEMAPPS. Press 3 then highlight ALL on the screen, press 1 , then highlight LOAD and press 2 to load the data into your calculator. Press the keys 2nd and then QUIT, and then run the program $\mathrm{SOLUBIL}$ . For $\mathrm{L}_{1}$ press 2nd and LIST and choose SOL21. If you are using another calculator, your teacher will provide you with keystrokes and data sets to use. $$\begin{array}{l}{\text { a. At what temperature would you expect }} \\ {\text { the solubility to be } 48.9 \text { g per } 100 \mathrm{g} \mathrm{H}_{2} \mathrm{O} \text { ? }} \\ {\text { b. At what temperature would you expect }} \\ {\text { the solubility to be } 35 \mathrm{g} \text { per } 100 \mathrm{g} \mathrm{H}_{2} \mathrm{O} \text { ? }} \\ {\text { c. What would you expect the solubility to }} \\ {\text { be at a temperature of } 100^{\circ} \mathrm{C} ?}\end{array}$$
