Question

Which of the following contains highest number of moles?

• A. $90$ g of water
• B. $130$ g of carbon dioxide
• C. $89.6$ L of oxygen at S.T.P.
• D. $12$ g of hydrogen gas

Answer 1

Answer: (D)

$12$ g of hydrogen gas

$No.ofmoles$ $=\frac{Weight}{GramMol.Weight}$ or, $\frac{VolumeatSTP}{22.4}$

No. of moles in $90$ g of water $=\frac{90}{18}=5$ moles

No. of moles in $130$ g of carbon dioxide $=\frac{130}{44}=2.95$ moles

No. of moles in $89.6$ L of oxygen at S.T.P. $=\frac{89.6}{22.4}=4$ moles

No. of moles in $12$ g of hydrogen $=\frac{12}{2}=6$ moles