Name__________________________________ Date________________ Period_________
Materials:
Part A: scale, salt, water, small container with lid
Part B: scale, 1/3 Alka-Seltzer tablet, water, 1L water bottle
Part A: Dissolving Salt in Water
Circle One: This is a PHYSICAL / CHEMICAL change
Hypothesis (circle one):
When we dissolve salt in water in a closed system, there will / will not be a change in mass.
Our group’s data:
Group #
Initial Mass Final Mass Change in
Mass
Class Data:
Group
#
Change in
Mass after Salt
Dissolved
1
2
3
4
5
6
Group
#
Change in
Mass after Salt
Dissolved
7
8
9
10
11
12
Part B: Dissolving Alka-Seltzer in Water
Circle One: This is a PHYSICAL / CHEMICAL change
Hypothesis (circle one):
When we dissolve an Alka-Seltzer tablet in a closed system, there will / will not be a change in mass.
Our group’s data:
Group #
Initial Mass
Final Mass
Change in Mass
BEFORE bottle cap
is loosened
Change in Mass
AFTER bottle cap is
loosened
Class Data:
Group #
1
2
3
4
5
6
Change in Mass
BEFORE bottle
cap is loosened
Change in Mass
AFTER bottle
cap is loosened
Group #
7
8
9
10
11
12
Change in Mass
BEFORE bottle
cap is loosened
Change in Mass
AFTER bottle
cap is loosened
1. Which experiment (the salt in water or the Alka-Seltzer in water) resulted in a chemical change? Explain your
answer.
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2. Which experiment (the salt in water or the Alka-Seltzer in water) resulted in a physical change? Explain your
answer.
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3. What happened to the salt in Part A?
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4. What happened when the two solutions from Part B were combined?
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5. Record the masses from your data for Part A.
6. Record the masses from your data for Part B.
5. When we dissolved salt in water, mass was / was not conserved.
6. When we dissolved Alka-Seltzer in water, mass was / was not conserved.
7. What could account for any difference between the initial and final masses of your mixtures?
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