Question

Calculate the enthalpy change of dissolving 5.00 g of NaOH in 100.0 g of water. The temperature of the resulting solution increases from 25.00°C to 31.50°C. The specific heat capacity of the resulting solution is 4.18 J/g°C.

Answer 1

To calculate the enthalpy change of dissolving NaOH in water, we can use the formula:q = mcTwhere q is the heat absorbed or released, m is the mass of the solution, c is the specific heat capacity, and T is the change in temperature.First, we need to find the mass of the solution. Since we have 5.00 g of NaOH and 100.0 g of water, the total mass of the solution is:m = 5.00 g + 100.0 g = 105.0 gNext, we need to find the change in temperature, which is:T = T_final - T_initial = 31.50C - 25.00C = 6.50CNow we can plug these values into the formula:q =  105.0 g  4.18 J/gC  6.50C  = 2871.7 JSince the temperature of the solution increased, the reaction is exothermic, and the enthalpy change is negative. Therefore, the enthalpy change of dissolving 5.00 g of NaOH in 100.0 g of water is:H = -2871.7 J