Answer: Each ion is surrounded by water molecules 
Explanation: The ions are surround by the water molecules which act as a barrier around the ions and prevent the recombination of ions. The ions are said to be hydrated. 
 
        
                    
             
        
        
        
CaCl2 +Na2CO3 ====>Nacl+CaCO3
        
             
        
        
        
The given formula for heat, Q=mc(Tf-Ti), is the best way to solve such problems with changes in temperature. It can be said that m is the mass of the substance. C is the specific heat of the substance. The term (Tf-Ti) is the change in temperature.
Q = mc(Tf-Ti) = 480g(0.96 J/g-C)(234-22) = 97689.6 Joules of heat
        
             
        
        
        
Moles of H2SO4= 7.5x10^23/ 6.02x10^23 = 1.25 (3sf) moles of H2SO4
Mass of 1 mole of H2SO4= 98.1g
Therefore mass of 7.5x10^23 molecules of H2SO4= 122.63g