Question

CASO4
2) Calculate the mass of calcium sulfate containing 120 g of calcium (Ar(Ca) = 40; A (S) = 32);
A (0) = 16):
4
b) 312 g
a) 528 g
correct
c) 360 g
d) 408 g
e) no answer is​

Answer 1

Answer:

Formula unit mass of CaSO

4

.2H

2

O

= (Number Calcium atoms x atomic mass of Calcium) + (Number Sulphur atoms x atomic mass of sulphur) + (Number Oxygen atoms x atomic mass of Oxygen) + (Number Water molecules x Molecular mass of water molecule)

=(1×40)+(1×32)+(4×16)+(2×18)

=40+32+64+36

=172

Formula unit mass of gypsum = 172