Question

Find the number of atoms present in 0.016

g of methane.​

Answer 1

Given - Mass of methane - 0.016 gram

Find - Number of atoms present in given mass of methane.

Solution - Molecular mass of methane is 16 g/mol.

Finding out number of moles of methane = 0.016/16 = 0.001.

As per the fact, 1 mole contains 6.023*10²³ atoms of an element or molecules of a compound.

Number of atoms = 5*0.001*6.023*10²³ (As methane contains five atoms)

Number of atoms = 3.01*10²¹.

Hence, the number of atoms present in 0.016g of methane is 3.01*10²¹.

Answer 2

Given:

0.016 grams of methane.

To find:

Number of atoms in it ?

Calculation:

First of all, let's find out the number of moles:

$\rm moles = \dfrac{given \: mass}{molar \: mass}$

$\rm \implies moles = \dfrac{0.016}{16}$

$\rm \implies moles = {10}^{ - 3} \: mol$

Now, number of molecules :

$\rm \implies molecules = moles \times avagadro \: no.$

$\rm \implies molecules = {10}^{ - 3} \times 6.023 \times {10}^{23}$

$\rm \implies molecules = 6.023 \times {10}^{20}$

Now, each molecule of methane has 5 atoms:

$\rm \implies total \: atoms = 6.023 \times {10}^{20} \times 5$

$\rm \implies total \: atoms = 3.0115 \times {10}^{21}$

So, total atoms is 3.0115 × 10²⁰ atoms of methane.