Can someone please answer question 8 and 11 please.

Two solutions, initially at 24.60C, are mixed in a coffee cup calorimeter. When a 100.0mL volume of 0.100MAgNO3 solution is mixed with a 100.0mL sample of 0.200MNaCl solution, the temperature in the calorimeter rises to 25.30C. Determine the Hrxn for the reaction as written below. Assume that the density and heat capacity of the solutions is the same as that of water. The specific heat capacity of water =4.18J/gC. NaCl(aq)+AgNO3(aq)AgCl(s)+NaNO3(aq)Hrxn=? A) 59kJ B) 16kJ C) 250kJ D) 35kJ E) 140kJ Express the equilibrium constant for the following reaction. CH4(g)+2O2(g)CO2(g)+2H2O(g) A) K=[CO2[2H2]2[CH4][2O22 B) K=[CO2][H2O2[CH4[O2]2 C) K=[CH4]2O2]2[CO2][2H2O]2 D) K=[CH4[O22[CO2][H2O]2 E) K=[CO2][H2O][CH4[O2]