An aqueous solution containing 85.0 wt% H2SO4 at 60F (specific gravity =1.78) is diluted

Chapter 8, Problem 8.110

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An aqueous solution containing 85.0 wt% \(\mathrm{H}_{2} \mathrm{SO}_{4}\) at 60°F (specific gravity =1.78) is diluted with pure liquid water at the same temperature. The feed solution volume is 350 mL. The mixing may be considered adiabatic, and the pressure is constant at 1 atm.

(a) The product solution is to contain 30.0 wt% \(\mathrm{H}_{2} \mathrm{SO}_{4}\). Calculate the volume (mL) of water needed for the dilution, ideally using a single-dimensional equation.

(b) Use the enthalpy–concentration chart of Figure 8.5-1 to estimate the specific enthalpies (Btu/lbm) of the feed solution and the water. Then write an energy balance on this closed system constant pressure process and solve it for the specific enthalpy of the product solution. Finally, use Figure 8.5-1 to verify your calculated value of \(\hat{H}_{\text {product }}\) and to estimate the product solution temperature. (See Example 8.5-3.)

(c) Use Figure 8.5-1 to estimate the maximum temperature that could be attained by mixing the feed solution with pure water and the concentration (wt% \(\mathrm{H}_{2} \mathrm{SO}_{4}\)) of the product solution.

(d) Good laboratory practice calls for adding acid to water when carrying out dilutions rather than vice versa. Use Figure 8.5-1 to justify this rule for the dilution of the feed solution in this problem.