Questions: Hydrochloric acid is typically purchased in a relatively highly concentrated form and then diluted by adding slowly to water to save money. The concentration of the purchased solution is 37.0% by mass HCl, and this solution has a density of 1.20 g/mL. What volume of the concentrated HCl solution is the correct amount needed to make 3.7 L of 0.435 M HCl? - 130 mL - 8.5 mL - 12 mL - 1.1 L - 96 mL

Hydrochloric acid is typically purchased in a relatively highly concentrated form and then diluted by adding slowly to water to save money. The concentration of the purchased solution is 37.0% by mass HCl, and this solution has a density of 1.20 g/mL.

What volume of the concentrated HCl solution is the correct amount needed to make 3.7 L of 0.435 M HCl?
- 130 mL
- 8.5 mL
- 12 mL
- 1.1 L
- 96 mL

Transcript text: 12. Hydrochloric acid is typically purchased in a relatively highly concentrated form and then diluted by adding slowly to water to save money. The concentration of the purchased solution is $37.0 \%$ by mass HCl , and this solution has a density of $1.20 \mathrm{~g} / \mathrm{mL}$. What volume of the concentrated HCl solution is the correct amount needed to make 3.7 L of 0.435 MHCl ? 130 mL 8.5 mL 12 mL 1.1 L 96 mL

Solution

Solution Steps

Step 1: Calculate the moles of HCl needed

Use the formula $ M = \frac{n}{V} $ where $ M $ is molarity, $ n $ is moles, and $ V $ is volume in liters.
Given $ M = 0.435 \, \text{M} $ and $ V = 3.7 \, \text{L} $: \[ n = M \times V = 0.435 \, \text{M} \times 3.7 \, \text{L} = 1.6095 \, \text{moles} \]

Step 2: Calculate the mass of HCl needed

Use the molar mass of HCl ($ 36.46 \, \text{g/mol} $): \[ \text{Mass of HCl} = 1.6095 \, \text{moles} \times 36.46 \, \text{g/mol} = 58.67 \, \text{g} \]

Step 3: Calculate the volume of the concentrated HCl solution needed

The concentrated solution is $ 37.0\% $ by mass HCl, so: \[ \text{Mass of solution} = \frac{58.67 \, \text{g}}{0.37} = 158.57 \, \text{g} \]
Use the density of the concentrated solution ($ 1.20 \, \text{g/mL} $): \[ \text{Volume of solution} = \frac{158.57 \, \text{g}}{1.20 \, \text{g/mL}} = 132.14 \, \text{mL} \]

Step 4: Select the closest answer