Question

Total number of hydrogen atoms in 4.9 g of sulphuric acid is:

• A. $3.01\times {10}^{22}$ atoms
• B. $6.022\times {10}^{22}$ atoms
• C. $1.5\times {10}^{22}$ atoms
• D. $12.044\times {10}^{22}$ atoms

Answer 1

The correct option is B $6.022\times {10}^{22}$ atoms

$Le{t}^{\prime }sfirstfindthenumberofmolesof{H}_{2}S{O}_{4}usingthemassgiven:$

$No.ofmoles,n=Mass/Molarmass$

$Molarmassof{H}_{2}S{O}_4=(2\times 1)+32+(4\times 16)=2+32+64=98g/mol$

$\therefore No.ofmoles\left(n\right)of{H}_{2}S{O}_4=4.9/98=0.05$

$\Rightarrow$ $No.ofHatoms$ $=2\times n\times Avogadrono.$ $=2\times 0.05\times 6.022\times {10}^{23}$

$=0.1\times 6.022\times {10}^{23}$

$=6.022\times {10}^{22}$