Question

From 50 gm of hydrogen, 24×10^23 molecules are removed then find out remaining no. of moles of hydrogen.

Answer 1

Given info : From 50gm of hydrogen, 24 × 10²³ molecules are removed out.

To find : the remaining no of moles of hydrogen is ..

solution : molar mass of hydrogen gas = 2 g/mol

so, no of moles of hydrogen = given mass/molar mass = 50g/2g/mol = 25 moles

no of molecules in 50g of hydrogen = no of moles of hydrogen × Avogadro's number

= 25 × 6.023 × 10²³

= 150.575 × 10²³

= 1.50575 × 10²⁵

now remaining no of hydrogen molecules = initially no of hydrogen molecules - no of molecules which are removed out

= 1.50575 × 10²⁵ - 24 × 10²³

= (150.575 - 24) × 10²³

= 126.575 × 10²³

now no of moles of hydrogen = no of molecules/Avogadro's number

= 126.575 × 10²³/6.023 × 10²³

= 21.0152748 ≈ 21 moles

Therefore the remaining no of moles of hydrogen is 21.

Answer 2

Answer:

21 mole

Explanation:

No. of molecules of hydrogen in 50g=(50/2)N.

                                                             =25x6x10^23=150x10^23

Remaining molecules =150x10^23-24x10^23

                                 =10^23(150-24)=126x10^23

No. of moles remained=126x10^23/6x10^23

                                        =21 moles