Question

Find the mass of 500 "particles" of Na2SO4 ?

Answer 1

Explanation:

Sodium sulfate is

N

a

2

S

O

4

First, calculate the moles of sodium sulfate you have in a 14.2g sample.

Find the molar mass of sodium sulfate

molar mass = atomic mass in grams

2(23) + 32 + 4(16) = 142 grams per mole

Divide the mass of the sample by the molar mass to obtain moles

14.2

g

142

g

m

o

l

−

1

= 0.1 mol

Now, for every 1 mol of

N

a

2

S

O

4

you have 2 moles of

N

a

+

ions. Multiple the moles of

N

a

2

S

O

4

that you found just then by 2 to obtain the moles of sodium ions.