Question 11 of 36beginner🔧 ApplyNumerical3 marks

What is the concentration of sugar (C₁₂H₂₂O₁₁) in mol L⁻¹ if its 20 g are dissolved in enough water to make a final volume up to 2L?

Correct Answer

0.0292 mol L−1^{-1}

Exercise: EXERCISES | Q: 1.11 | (Page 26)
For More Understanding

Explanation

To find the concentration in mol L−1^{-1} (molarity), we first need to determine the number of moles of the solute (sugar). This is done by dividing the given mass of sugar by its molar mass. Then, we divide the number of moles by the final volume of the solution in litres.

Solution Steps

  1. Step 1: Calculate the molar mass of sugar (C12H22O11C_{12}H_{22}O_{11}). Molar mass = 12×12+22×1+11×16=144+22+176=34212 \times 12 + 22 \times 1 + 11 \times 16 = 144 + 22 + 176 = 342 g mol−1^{-1}

  2. Step 2: Calculate the number of moles of sugar. Number of moles = Given massMolar mass=20 g342 g mol−1=0.0585\frac{\text{Given mass}}{\text{Molar mass}} = \frac{20 \text{ g}}{342 \text{ g mol}^{-1}} = 0.0585 mol

  3. Step 3: Calculate the concentration in mol L−1^{-1}. Concentration = Number of moles of soluteVolume of solution in L=0.0585 mol2 L=0.0292\frac{\text{Number of moles of solute}}{\text{Volume of solution in L}} = \frac{0.0585 \text{ mol}}{2 \text{ L}} = 0.0292 mol L−1^{-1}

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