How many molecules of sucrose are present in 14.3 mL of a 0.140 M sucrose solution?

• A. 6.02 × 10^{23} molecules
• B. 1.21 × 10^{21} molecules
• C. 7.53 × 10^{20} molecules
• D. 3.61 × 10^{22} molecules

Answer: (B)

Verified step by step guidance

1. Identify the given information: volume of solution = 14.3 mL, molarity (M) of sucrose = 0.140 mol/L.
2. Convert the volume from milliliters to liters because molarity is in mol/L. Use the conversion: \$1\, \text{mL} = 0.001\, \text{L}\(, so \)14.3\, \text{mL} = 14.3 \times 0.001\, \text{L}$.
3. Calculate the number of moles of sucrose in the given volume using the formula: \(\text{moles} = \text{molarity} \times \text{volume in liters}\).
4. Use Avogadro's number, \$6.022 \times 10^{23}\( molecules/mol, to convert moles of sucrose to number of molecules: \)\text{molecules} = \text{moles} \times 6.022 \times 10^{23}$.
5. Perform the multiplication to find the total number of sucrose molecules in the 14.3 mL solution.