Question

Which of the following would weigh the highest?

• A. 0.2 mole of sucrose $\left(C_{12}{H}_{22}{O}_{11}\right)$
• B. 2 moles of carbon dioxide $\left(C{O}_2\right)$
• C. 2 moles of calcium carbonate $\left(CaC{O}_3\right)$
• D. 10 moles of water $\left(H_{2}O\right)$

Answer 1

The correct option is C 2 moles of calcium carbonate $\left(CaC{O}_3\right)$

Applying mole concept,

1 mole $=$ molecular weight in gram.

Molecular weight of $C_{12}{H}_{22}{O}_{11}=12\times 12+22\times 1+11\times 16=342$

Molecular weight of $C{O}_2=12+2\times 16=44$

Molecular weight of $CaC{O}_3=40+12+3\times 16=100$

Molecular weight of $H_{2}O=16+2\times 1=18$

The results can be calculated as:

Weight of a sample in gram $=$ number of moles $\times$ molar mass

(a) 0.2 moles of $C_{12}{H}_{22}{O}_{11}=0.2\times 342=68.4gm$

(b) 2 moles of $C{O}_2=2\times 44=88gm$

(c) 2 moles of $CaC{O}_3=2\times 100=200gm$

(d) 10 moles of $H_{2}O=10\times 18=180gm$

Hence, 2 moles of $CaC{O}_3$ weighs more than other compounds.