Sulfuric acid is used in the synthesis and processing of countless chemicals and metals and is the electrolyte in common lead-acid batteries. It is used in various strengths, ranging from concentrated (100%) to dilute, so being able to estimate its concentration from a simple measurement of specific gravity is quite useful. 

Suppose you prepare a solution that is 30.0 wt% H₂SO₄ in water and intend to confirm the concentration by comparing the specific gravity of the solution to a value obtained from the literature. You carefully add 30.0 g of H₂SO₄ to 70.0 g of water (you know that rapidly adding acid to water or water to concentrated acid can lead to dangerous splatters of liquid) and allow the resulting mixture to equilibrate at 20°C. 

(a) From the specific gravities in Table B.1, estimate the volumes of water and sulfuric acid that have been blended, and then estimate the density of the 30.0 wt% sulfuric acid solution, assuming the volumes are additive. Why are the values of pure-component specific gravities different from those in Example 5.1-1, and what is the effect of these differences on the total volume of the mixture? 

(b) Perry’s Chemical Engineers’Handbook( gives the specific gravity of sulfuric acid as a function of both acid concentration and temperature. The value for 30.0 wt% sulfuric acid at 20°C is given as 1.2185. Estimate the volume of the 30.0 wt% solution prepared as described by the above process. 

(c) What volume of 40.0 wt% sulfuric acid at 25°C (SG = 1.2991) must be added to 100.0 g of the 30.0-wt% solution to produce a solution that is 35.0 wt% sulfuric acid?