Question

Average atomic mass of carbon is 12.01 u. Find the number of moles of carbon in (a) 2.0 g of carbon. (b) 8.0 g of carbon.

Answer 1

Answer:

moles = given mass / atomic mass.

Answer 2

Answer:

(a)No. of moles(n) = 0.167 moles.

(b)No. of moles(n) = 0.667 moles.

Explanation:

We know the formula for No. of moles(n) = $\frac{given\ mass}{molar\ mass}$

Here molar mass is also a average atomic mass.

(a)For a 2 gm of carbon, given mass = 16 gm

So,

No. of moles(n) = $\frac{2}{12.01}$ = 0.167 moles.

(b)For a 8 gm of carbon, given mass = 8 gm

So,

No. of moles(n) = $\frac{8}{12.01}$ =0.667 moles.