Question

How many atoms of each element are there in $9.8g$ of sulphuric acid,${\mathrm{H}}_2{\mathrm{SO}}_4$?(atomic mass,$\mathrm{H}=1,\mathrm{S}=32,\mathrm{O}=16$)

Answer 1

• The total molecular weight of sulfuric acid ${\mathrm{H}}_2{\mathrm{SO}}_4$= $1\times 2+32+16\times 4$ = $98\mathrm{u}$
• Number of moles of ${\mathrm{H}}_2{\mathrm{SO}}_4$ = Given mass/ Molecular mass = $9.8/98=0.1mol$
• Number of Hydrogen ($\mathrm{H}$) atoms in sulphuric acid = $0.1\times 2\times 6.022\times {10}^{23}$=$1.2044\times {10}^{{23}^{}}$atoms
• Number of Sulfur ($\mathrm{S}$) atoms in sulphuric acid = $0.1\times 1\times 6.022\times {10}^{23}$= $0.6022\times {10}^{23}$atoms
• Number of Oxygen( $\mathrm{O}$)atoms in sulphuric acid = $0.1\times 4\times 6.022\times {10}^{23}=2.4\times {10}^{23}$atoms