Question

Find the number of atoms present in 0.25 moles of hydrogen.

Answer 1

number of mole s of $H_2$ = 0.25 moles

number of molecules = moles * Avogadro’s Number

number of molecules = $0.25\times (6.022\times {10}^{23})$

number of molecules = $1.505\times {10}^{23}$

single molecule of hydrogen contains two H-atoms. So,

number of atoms = $2\times (1.505\times {10}^{23})$ = $3.01\times {10}^{23}$