Lesson 10: Wrap Up
In this lesson you have used your understanding of solubility rules, precipitation reactions, and the properties of acids and bases to experimentally determine the identities of some unknown solutions. The self quiz in this section gives you some additional practice with those skills.
Self Quiz
1. Which of the following properties would indicate an acid?
I. pH less than 7
II. Turns litmus paper to a blue color.
III. Turns phenolphthalein to a pink color.
a. I only
b. II only
c. I and II
d. I and III
e. II and III
2. Which of the following reactions would indicate a base?
a. reacts with water to give H3O+
b. reacts with water to give H2
c. reacts with a metal to give H2
d. reacts with HCO3- to give CO2
e. reacts with NH4+ to give NH3
Answer the following questions in the space provided.
3. Balance this equation and determine whether a precipitate is formed.
CaCl2 + AgNO3
AgCl + Ca(NO3)2
4. Write a complete balanced equation for the reaction between iron(III) chloride and lead(II) nitrate. Is this a precipitation reaction? If so, identify the precipitate.
5. Write a complete balanced equation for the reaction between ammonium sulfide and copper(II) chloride. Is this a precipitation reaction? If so, identify the precipitate.
6. Write formulas for the following chemicals and determine whether they are soluble or insoluble in water.
| sodium sulfate | calcium nitrate | iron(III) carbonate |
7. Abbreviated solubility rules:
> All sodium, potassium and ammonium salts are soluble.
> All chloride salts are soluble except PbCl2, AgCl and HgCl.
> All nitrate salts are soluble.
> Hydroxides are insoluble except for NaOH, KOH and NH4OH.
Four solutions in bottles numbered 1 through 4 are:
AgNO3 HCl Mg(NO3)2 NaOH
Results of lab tests:
#1 is basic and precipitates with #3 and #4.
#2 is acidic and precipitates with #3.
#3 precipitates with #1 and #2.
#4 precipitates with #1.
Which chemical is in each bottle?
Self Quiz Answers
1. Which of the following properties would indicate an acid?
I. pH less than 7
II. Turns litmus paper to a blue color.
III. Turns phenolphthalein to a pink color.
*a. I only
2. Which of the following reactions would indicate a base?
*e. reacts with NH4+ to give NH3
Answer the following questions in the space provided.
3. Balance this equation and determine whether a precipitate is formed.
CaCl2 + 2 AgNO3 2 AgCl(ppt) + Ca(NO3)2
4. Write a complete balanced equation for the reaction between iron(III) chloride and lead(II) nitrate. Is this a precipitation reaction? If so, identify the precipitate.
This is a precipitation reaction and lead(II) chloride is the precipitate.
2 FeCl3 + 3 Pb(NO3)2 3 PbCl2(ppt) + 2 Fe(NO3)3
5. Write a complete balanced equation for the reaction between ammonium sulfide and copper(II) chloride. Is this a precipitation reaction? If so, identify the precipitate.
This is a precipitation reaction and copper(II) sulfide is the precipitate.
(NH4)2S + CuCl2 CuS(ppt) + 2 NH4Cl
6. Write formulas for the following chemicals and determine whether they are soluble or insoluble in water.
sodium sulfate |
calcium nitrate |
iron(III) carbonate |
Na2SO4 |
Ca(NO3)2 |
Fe2(CO3)3 |
soluble |
soluble |
insoluble |
7. Four solutions in bottles numbered 1 through 4 are:
AgNO3 HCl Mg(NO3)2 NaOH
Results of lab tests:
#1 is basic and precipitates with #3 and #4.
#2 is acidic and precipitates with #3.
#3 precipitates with #1 and #2.
#4 precipitates with #1.
Which chemical is in each bottle?
| 1 | 2 | 3 | 4 |
| NaOH | HCl | AgNO3 | Mg(NO3)2 |