ΔH=MCΔT
ΔH=100 x 4.2 x 4
ΔH=1680
ΔH per mole = ΔH ÷ moles
ΔH per mole = 1680 ÷ 0.02
<span>ΔH per mole= 84000Jmol
</span>84000 ÷ 1000 = 84KJmol
its exothermic as heat is given out into the solution
The temperature changes by <span>#-173 ^(o) C#</span>
2 - PE of products-PE of reactants.
You are trying to calculate the energy change that occurred from the start of the reaction (the reactants going in) to the end of the reaction (the products coming out). Therefore if there is more energy at the end, you will get a positive result from subtracting the PE of the reactants, and vice versa.
(6.0×10^4) = 60,000
(3.1×10^-1) = 0.31
60,000 × 0.31 = 18,600
