Question

1. a student mixed 3 moles of kf with enough water to make 740 ml of solution. what is the molarity of the solution?
2. a solution of cuso₄ is made by dissolving.15 g in enough water to make 150 ml of solution. what is the molarity of the solution?
3. 500 ml of solution is made from 3.12 g of ca(no₃)₂. what is the molarity of the solution?
4. how many grams of nacl would be needed to make 2.00 l of a 0.100 m solution?
5. hcl is purchased as a 12 m solution. how many ml of this stock solution would be needed to make 200 ml of.3 m solution?
6. a student made 50 ml of a.100 m solution using 13 ml of an unknown solution. what was the molarity of the unknown solution?

Explanation:

Let's solve question 13 as an example (you can choose any other question following the same method):

Question 13:

A student mixed 3 moles of KF with enough water to make 740 mL of solution. What is the molarity of the solution?

Step 1: Recall the formula for molarity

Molarity ($M$) is defined as moles of solute ($n$) divided by volume of solution in liters ($V$). The formula is $M = \frac{n}{V}$.

Step 2: Convert volume to liters

The volume of the solution is 740 mL. Since 1 L = 1000 mL, we convert 740 mL to liters: $V = \frac{740}{1000} = 0.74\space L$.

Step 3: Calculate molarity

We know the moles of KF ($n$) is 3 moles and the volume ($V$) is 0.74 L. Using the molarity formula: $M = \frac{3\space mol}{0.74\space L} \approx 4.05\space M$.

Answer:

The molarity of the solution is approximately $\boldsymbol{4.05\space M}$.