Question

What is the mass of 5.00 moles of KaS04?

A
34.8 grams
B
174 grams
C
675 grams
D
870 grams

Answer 1

Answer: D

Step-by-step explanation:

I assume you meant
`\text{K}_(2)\text{SO}_(4)`.

• The atomic mass of potassium is 39.0983 g/mol.
• The atomic mass of sulfur is 32.065 g/mol.
• The atomic mass of oxygen is 15.9994 g/mol.

So, the formula mass of potassium sulfate is 2(39.0983)+32.065+4(15.9994)=174.2592 g/mol.

So, 5.00 moles have a mass of (5.00)(174.2592), which is about 870 g