Answer
a. 0.833 mL $KNO_3$ solution.
b. 5.21 mL $H_2SO_4$ solution.
c. 75.0 mL $NH_4Cl$ solution.
Work Step by Step
1. Write the dilution expression, and solve for the initial volume $(V_1)$
$C_1V_1 = C_2V_2$
$$V_1 = \frac{C_2V_2}{C_1} $$
a.
2. Substitute the values and calculate the initial volume:
$$V_1 = \frac{(20.0 \space mL)(0.250 \space M)}{6.00 \space M}$$
$$V_1 = 0.833 \space mL$$
b.
2. Substitute the values and calculate the initial volume:
$$V_1 = \frac{(25.0 \space mL)(2.50 \space M)}{12.0 \space M}$$
$$V_1 = 5.21 \space mL$$
c.
2. Substitute the values and calculate the initial volume:
$$V_1 = \frac{(0.500 \space L)(1.50 \space M)}{10.0 \space M} \times \frac{1000 \space mL}{1 \space L}$$
$$V_1 = 75.0 \space mL$$
