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What is the molarity of a solution that contains 25 g of HCl in 150 mL of solution? (The molar mass of HCl is [tex]36.46 \, g / mol[/tex].)

1. What should you find first?

2. Which setup is correct for finding moles?
A. [tex]25 \, g \, HCl \times \frac{36.46 \, g \, HCl}{1 \, mol \, HCl}[/tex]
B. [tex]25 \, g \, HCl \times \frac{1 \, mol \, HCl}{36.46 \, g \, HCl}[/tex]

3. Which setup is correct to find liters?
A. [tex]150 \, mL \times \frac{1000 \, mL}{1 \, L}[/tex]
B. [tex]150 \, mL \times \frac{1 \, L}{1000 \, mL}[/tex]

4. What is the molarity of this solution?
A. 4.5 M HCl



Answer :

GinnyAnswer
To determine the molarity of a solution containing 25 grams of HCl in 150 mL of solution, we need to follow a series of steps. Here's a detailed, step-by-step solution:

1. Find the number of moles of HCl:
- The formula used to convert grams to moles is:
[tex]\[ \text{moles of HCl} = \frac{\text{mass of HCl (in grams)}}{\text{molar mass of HCl (in g/mol)}} \][/tex]
- Given:
[tex]\[ \text{mass of HCl} = 25 \text{ grams} \][/tex]
[tex]\[ \text{molar mass of HCl} = 36.46 \text{ g/mol} \][/tex]
- Therefore, the number of moles of HCl is:
[tex]\[ \text{moles of HCl} = \frac{25 \text{ g}}{36.46 \text{ g/mol}} \approx 0.6857 \text{ moles} \][/tex]
- The correct setup to find the moles of HCl is:
[tex]\[ 25 \text{ g HCl} \times \frac{1 \text{ mol HCl}}{36.46 \text{ g HCl}} \][/tex]

2. Convert the volume of solution from mL to L:
- The formula to convert milliliters to liters is:
[tex]\[ \text{volume in liters} = \frac{\text{volume in mL}}{1000} \][/tex]
- Given:
[tex]\[ \text{volume of solution} = 150 \text{ mL} \][/tex]
- Therefore, the volume in liters is:
[tex]\[ \text{volume in liters} = \frac{150 \text{ mL}}{1000} = 0.15 \text{ L} \][/tex]
- The correct setup to convert volume is:
[tex]\[ 150 \text{ mL} \times \frac{1 \text{ L}}{1000 \text{ mL}} \][/tex]

3. Calculate the molarity of the solution:
- Molarity is defined as the number of moles of solute per liter of solution:
[tex]\[ \text{Molarity (M)} = \frac{\text{moles of solute}}{\text{volume of solution in liters}} \][/tex]
- Given:
[tex]\[ \text{moles of HCl} \approx 0.6857 \text{ moles} \][/tex]
[tex]\[ \text{volume of solution} = 0.15 \text{ L} \][/tex]
- Therefore, the molarity of the solution is:
[tex]\[ \text{Molarity} = \frac{0.6857 \text{ moles}}{0.15 \text{ L}} \approx 4.57 \text{ M} \][/tex]

The molarity of the solution is approximately [tex]\(4.57 \text{ M}\)[/tex].

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