Question

if you measured out 0.200 moles of nacl, and dissolved it in 0.500 l solution, what would be the molarity of the solution? (hint: use eq. 1)
0.700 m
2.50 m
0.100 m
0.400 m
question 5
4 pts
50.00 ml of a 0.200 m solution of sucrose is diluted to 500.00 ml. what is the molarity of the final solution?
0.0200 m
2.00 m
0.364 m
0.200 m

Explanation:

Step1: Recall the formula for molarity

Molarity \(M=\frac{n}{V}\), where \(n\) is the number of moles of solute and \(V\) is the volume of the solution in liters.
For the first problem:
Given \(n = 0.200\space mol\) and \(V=0.500\space L\)
\(M=\frac{0.200\space mol}{0.500\space L}\)

Step2: Calculate the molarity

\(M = 0.400\space M\)

For the second problem:
Use the dilution formula \(M_1V_1 = M_2V_2\)
Given \(M_1 = 0.200\space M\), \(V_1=50.00\space mL = 0.05000\space L\), \(V_2 = 500.00\space mL=0.50000\space L\)
\(M_2=\frac{M_1V_1}{V_2}\)
\(M_2=\frac{0.200\space M\times0.05000\space L}{0.50000\space L}\)
\(M_2 = 0.0200\space M\)

Answer:

For the first question: \(0.400\space M\)
For the second question: \(0.0200\space M\)