Solve for the unknown quantity.

(0.10 Eq/L)(5.2 mL)

C2 = ------------------ = 0.10 Eq/L

5.0 mL

Convert the concentration to mEq/L to satisfy the problem using the

appropriate conversion factor.

0.10 Eq

1000 mEq

--------X ------------= 100 mEq/L

L

1 Eq

Solution. Solving the problem with dimensional analysis yields the same

results.

Determine the equivalents of base used in the titration.

1L

0.10 Eq

5.2 mL X --------X --------= 0.00052 Eq

1000 mL

L

According to the "Rule of Equivalence," an equal amount of acid is needed to

neutralize the solution.

The desired number of equivalents of acid per given volume of acid used in

the titration times the appropriate conversion factors yield the desired results.

0.00052 Eq

1000 mL

1000 mEq

------------X ----------X ------------= 100 mEq/L

5.0 mL

1L

1 Eq

c. **Example 2**. A 0.25 mol/L H2SO4 solution was used to titrate 4.0 mL of a 1.0

Eq/L NaOH solution. What volume of acid was required to perform the titration?

Solution. Read the problem carefully and select the expression that will allow

you to solve the problem for the unknown quantity.

C1V1 = C2V2

The concentration of the sulfuric acid in this problem is in mol/L and must be

converted to Eq/L. Convert 0.25 mol/L H2SO4 to Eq/L.

MD0837

7-5

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