|
Description of Action |
Action |
| 1.
Calculate the gram formula mass of the salt and the water separately.
Hint: It is helpful to remember that the gram formula mass of water
is 18.0 grams/mole. |
Ca:
1 x 40.1 = 40.1
S: 1 x 32.1 = 32.1
O: 3 x 16.0 = 48.0
120.2
H: 2 x 1.0 = 2.0
O: 1 x 16.0 = 16.0
18.0
|
| 2.
Divide each given mass or percentage by the substance’s gram
formula mass. |
CaSO3:
76.9÷ 120.2 = 0.640
H2O: 23.1÷ 18.0 = 1.28
|
| 3.
Divide each result by the smallest result. The smallest result should
always be the salt’s result. If not, double check your work.
|
CaSO3:
0.640÷ 0.640 = 1
H2O: 1.28 ÷ 0.640 = 2
|
| 4.
You will always get a whole number result. Write the formula by putting
water’s value in front of its formula. |
CaSO3
* 2H2O
|
| 5.
Name the compound. |
calcium sulfate dihydrate
|
