Question

Looking at the solubility curve above for KClO3, at 30 degrees Celsius how many grams will dissolve to make a saturated solution?

A. about 120 g (WRONG ANSWER)

B. 37 g

C. 10 g

D. 5 g


2. KCl is used to test the factors that affect the rate of dissolution.

Investigation 1 data:

Trial Number Temperature (oC) Stirring Dissolving Time (minutes)

1 20 no 30

2 40 no 20

3 60 no 10

How should the student design investigation 2 to finish testing the factors that affect the dissolving rate of KCl?

ANSWER: Keep the temperature at 20°C. Stir the solution.


3.How would you increase the conductivity of a solution?

A. Increase the temperature of the solution.

B. Use a weaker acid or base to make the solution.

C. Increase the concentration of ions in the solution.

D. Decrease the concentration of ions in the solution. (WRONG ANSWER)


4. Match what you know about the above solutions and their conductivity.

A solution like solution A that can conduct electricity ---- ELECTROLYTE

Solution B could have this dissolved in it------BOTH

Solution A could have this dissolved in it------ SALT, ACID, BASE


5. Sugar is added to tea to make sweet tea. In chemical terms, the sugar is the ___________ and the tea (mostly water) is the ____.

ANSWER: SOLUTE, SOLVENT


6. According to the pH chart, which is the strongest base?

ANSWER: NaOH


7.

Bleach

Hand Soap

Ammonia

What property do all three of these common household substances have in common?

When dissolved in water, they release hydrogen ions.

They all turn red litmus blue.

The react with metals to form hydrogen gas.(WRONG ANSWER)

They are all sour.


8. Match each to below to the area in which it belongs in the VENN diagram.

acid, base, or both

changes color in an indicator -- _____(Base is the wrong answer for this one)

Yields OH- ions in solution -- BASE(CORRECT)

pH is below 7---------------------ACID (CORRECT)

tastes sour------------------------ACID(CORRECT)

can conduct electricity in water- _____(Acid is the wrong answer for this one)


9. Use the information on the solubility graph to answer the question.

If 100 grams of the salt KBr are added to 100 g of water at 20oC, how would you describe the concentration of the solution?

ANSWER: SUPERSATURATED


10. What two products result from the neutralization reaction of an acid and a base?

For example: HCl + NaOH --> _____ + ______

ANSWER: SALT AND WATER


11. Jason is making lemonade and is getting impatient waiting for the sugar to dissolve. How can he speed up the rate of dissolution of the sugar?

A. Break up the sugar so the particle size is smaller.

B. Agitate the lemonade solution.

C. Add additional solute.

D. Increase the temperature of the lemonade. Then add ice to cool it back down so it doesn't taste bad.

Choose ALL correct answers.

CORRECT ANSWER: Increase the temperature of the lemonade. Then add ice to cool it back down so it doesn't taste bad.


12. How quickly will a mint dissolve?

Solute Time to dissolve (seconds)

mint cut in half, not swirled 140

mint cut in half, swirled 70

whole mint, not swirled 200

whole mint, swirled ?

mint cut into small pieces, not swirled 50



Students were asked to place a mint in their mouths and determine how long it took for the mint to dissolve. The condition of the mint varied in each student group.

One group of students were asked to leave a whole mint in their mouth, not moving it around, and let it dissolve. Another group swirled a whole mint around in their mouths, while the other groups used mints broken into smaller pieces. See the chart for all of the manipulated variables.


After reviewing that data table, what kind of result would you predict for the swirled, whole mint?


between 20 and 30 seconds

between 160 and 220 seconds

between 80 and 100 seconds

between 40 and 60 seconds(Incorrect answer)

HINT: Notice how the time changes when comparing the mint that has been cut in half. How does the time change when the students swirl that one around?


13. You are pulling your little sister along in a wagon. You exert 45 Newtons and are able to pull her 20 meters. How many joules of work did you do? Remember to consult your equation sheet for this one!


HINT: Did you find the work equation on your equation sheet? Work = force x distance? Take a look at the equation sheet and find it on there. Do you see how the F and d are next to each other? That means you will multiply the force and the distance.

Answer 1

1. An unsaturated solution is a solution that contains less amount of solute than it can normally hold at a particular temp. In a graph it is depicted in the region below the equilibrium curve (this shows the saturated solution). Saturated solution contains exact amount of solute. Supersaturated solution contains more solute than it can hold. It is depicted at the region above the equilibrium curve

2.Keep the temperature at 20 degrees C. Stir the solution.

3. The more concentrated a solution is, the higher the conductivity is. In most cases it is a proportional relationship. As the ion concentration increases, the conductivity increases.

4. ELECTROLYTE,

both

salt, acid, and base

5. SOLUTE, SOLVENT

6. N a O H

7. I don't know the question

8.acid

base

acid

acid

base

9. SUPERSATURATED

10.SALT AND WATER

11. Increase the temperature of the lemonade. Then add ice to cool it back down so it doesn't taste bad.

12. between 80 and 100 seconds

13.Multiply mass times acceleration.