Question

A person adds $1.71$ gram of sugar $\left(C_{12}{H}_{22}{O}_{11}\right)$ in order to sweeten his tea. The number of carbon atoms added are (mol. mass of sugar $=342$)

• A. $3.6\times {10}^{22}$
• B. $7.2\times {10}^{21}$
• C. $0.05$
• D. $6.6\times {10}^{22}$

Answer 1

Answer: (A)

$3.6\times {10}^{22}$

Answer:

Sugar is sucrose, which has a formula of $C_{12}{H}_{22}{O}_{11}$ and a molecular weight of $342$.

Number of moles of sucrose in $1.71$ grams = $0.005$

The number of molecules is the product of the number of moles and Avogadro's number

Number of molecules $=0.005\times 6.02\times {10}^{23}$

Number of carbon atoms $=12\times 0.005\times 6.02\times {10}^{23}$

$=3.6\times {10}^{22}$

Option A is the correct answer