Considerando as equações abaixo: 5
C2H2(g) +5026) 2 CO2(g) + H2050 AH = – 1.299,5 kJ
Cigr) + O2(g) + CO2(g) AH = – 393,5 kJ
1
H2(g) + 2 02(0) H20) AH 5 – 285,8 k]
Calcule a variação de entalpia da reação:
2 C(gr) + H2(g) → C2H2(g)
O (A) +226,7 kJ
O (B) +620,2 kJ
O(C) +798,3 ku
(D) -1.978,8 kJ
(E)-2.372,3 kJ

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

wanswer:

explanation: