For an endothermic reaction, which of the following conditions must be true for all products

the change in entropy is positive and change in enthalpy is negative. and potential energy is lower. and the reason is materials in nature naturaly want to get stabler and more chaotic.

for the second question there is a big formula. Equilibrium θ=mcθ1 (water) + mcθ1 (metal) / mc (water) + mc (metal) just put numbers and it is easy to solve. equlibrium temperture is 23.5