Find the number of molecules in the given quantity of a compound whose molar mass is given. Express your answer in scientific notation, rounding the decimal part to the nearest hundredth.
-22 grams of glucose $\left(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\right)$; molar mass 160.18 grams
A) $8.27 \times 10^{22}$ molecules
B) $2.12 \times 10^{27}$ molecules
C) $2.12 \times 10^{28}$ molecules
D) $8.27 \times 10^{21}$ molecules

Question

Quizplus · Accepted Answer

To find the number of molecules, first calculate the number of moles of glucose: $22 \, \text{grams} \div 160.18 \, \text{g/mol} = 0.137 \, \text{moles}$. Then, use Avogadro's number ($6.022 \times 10^{23}$ molecules/mol) to find the number of molecules: $0.137 \, \text{moles} \times 6.022 \times 10^{23} \, \text{molecules/mol} = 8.27 \times 10^{22}$ molecules.

Find the Number of Molecules in the Given Quantity of a Compound