Question

calculate the number of atoms present in 104 g of c2h2​

Answer 1

To find:

The number of atoms present in 104 g of C2H2?

Calculation:

First of all, let's calculate the number of moles of ethyne :

$\sf \therefore \: no. \: of \: moles = \dfrac{given \: mass}{molar \: mass}$

$\sf \implies \: no. \: of \: moles = \dfrac{104}{26}$

$\sf \implies \: no. \: of \: moles = 4$

Now, number of molecules present:

$\sf \implies \: no. \: of \: molecules= 4 \times N_{A}$

$\sf \implies \: no. \: of \: molecules= 4 \times 6.023 \times {10}^{23}$

Now, in 1 molecule, ethyne has 4 atoms, so total number of atoms in given molecules is :

$\sf \implies \: no. \: of \: atoms= 4 \times 6.023 \times {10}^{23} \times 4$

$\sf \implies \: no. \: of \: atoms= 16 \times 6.023 \times {10}^{23}$

$\sf \implies \: no. \: of \: atoms= 96.368 \times {10}^{23}$

So total number of atoms of ethyne is 96.368 × 10²³.