Question

If 300g of caco3 there find out number of atoms in caco3

Answer 1

Molecular mass of calcium carbonate = 40 + 12 + 48 =100g

1 mole of Calcium carbonate contains – 3 mole of oxygen atoms

100 g of Calcium carbonate contains - 3 X 6.022 X 1023 oxygen atoms

300g of Calcium carbonate contains - How many oxygen atoms? = 300 X 3 X 6.022 X 1023/ 100 = 54.205 X 1023 oxygen atoms

Answer 2

Mass of Calcium Carbonate given = 300 grams

Molar mass of Calcium Carbonate :-

$= 40 + 12 + 48 \\ \\ \\ = 40 + 60 \\ \\ \\ = 100 \: units$

$\rule{200}{2}$

Thus,

Number of moles of Calcium Carbonate will be :-

$moles = \frac{mass \: given}{molar \: mass} \\ \\ \\moles = \frac{300}{100} = 3 \: moles$

$\rule{200}{2}$

Now,

$1 \: mole = 6.022 \times {10}^{23} \:molecules$

$N_A=6.022 \times10^{23}$

$\rule{200}{2}$

Thus,

3 moles of Calcium Carbonate has :-

$=3N_A\:molecules$

$\rule{200}{2}$

Now,

1 molecule of CaCO3 has :-

☸️ 1 Calcium atom

☸️ 1 carbon atom

☸️ 3 oxygen atom

So,

In total 5 atoms.

$\rule{200}{2}$

Thus,

Total atoms present in 3 mole of CaCO3 will be :-

$5\times 3N_A\\ \\ \\=15N_A\:atoms$