Why does mixing reactants in different molar ratio’s affect the amount of product and the amount of each reactant that is leftover?

If you add 10ml of hot water to 10ml of cold water and the change in tempature 8°c calculate how much energy is gained by the cold water

The conventional equilibrium constant expression (kc) for the system below is: 2icl(s) ⇄ i2(s) + cl2(g) [cl2] ([i2] + [cl2])/2[icl] [i2][cl2]/[icl]2 none of the listed answers are correct [i2][cl2]/2[icl]

Which of these is a physical property