Find the ΔHr0 for the reaction of one mole of solid magnesium carbonate that decomposes into one mole of solid magnesium oxide and one mole of carbon dioxide gas.

MgCO3(s)→MgO(s) + CO2(g)

Answer choice:
A.)ΔHr0= -45.3kJ
B.)ΔHr0= +105.8kJ
C.)ΔHr0= +125.7kJ
D.)ΔHr0= +117.0kJ
E.)ΔHr0= -140.0kJ

it is stable as it is in group 0 which have full outer shells of electrons

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o