The temperature achieved when two fluid streams of differing temperature and/or composition are adiabatically mixed is termed the adiabatic mixing temperature. Compute the adiabatic mixing temperature for the following two cases: 

a. Equal weights of aqueous solutions containing 10 wt % sulfuric acid at 20°C and 90 wt % sulfuric acid at 70°C are mixed. 

b. Equal weights of aqueous solutions containing 10 wt % sulfuric acid at 20°C and 60 wt % sulfuric acid at 0°C are mixed. 

Explain why the adiabatic mixing temperature is greater than that of either of the initial solutions in one of these cases, and intermediate between those of the initial solutions in the other case.