Question

Calculate the number of oxygen atoms present in $88\text{g}$ of $C{O}_2$. What would be the mass of $CO$ that has the same number of oxygen atoms?

• A. $128\text{g}$
• B. $136\text{g}$
• C. $112\text{g}$
• D. $122\text{g}$

Answer 1

The correct option is C $112\text{g}$

Number of moles of $C{O}_2$ = $\frac{88\text{g}}{44{\text{g mol}}^{-1}}=2$ moles
As one mole of $C{O}_2$ contains two moles of oxygen atoms, two moles of $C{O}_2$ contains 4 moles of oxygen atoms.
Number of oxygen atoms $=4\times 6.023\times {10}^{23}$
$=2.4092\times {10}^{24}$
As 1 mole of oxygen atoms is present in 1 mol of $CO$, 4 moles of oxygen atoms are present in 4 moles of $CO$. Its mass is $4(12+16)=112\text{g}$