Question

Calculate the number of molecules of hydrogen and carbon present in 4g of methane

Answer 1

Molar Mass of 1 molecule of methane(CH4) = 12 + 4 = 16g/mol

That is, 16g if CH4 contain 1 mole molecule of it

= 6.022×10²³ molecules of CH4 which consists of 1 mole of C atoms and 4 moles of H atoms.

=> 4 g of CH4 contains 1/4 × 6.022×10²³ molecules

= 1.5055×10²³ molecules of CH4

= 1.5055×10²³ C atoms and 6.022×10²³ H atoms

Note: the question should be how many atoms of hydrogen and carbon and not molecules.

Hope it helps…

Answer 2

$\underline{\boxed{\bf 15.05\times 10^{22} molecules\: of\: Carbon}}$

$\underline{\boxed{\bf 6.023\times 10^{23} molecules\:of\: Hydrogen}}$

Refer to the attachment for calculations