Which of the following circumstances will result in a reaction that is spontaneous at all temperatures?
positive enthalpy change and positive entropy change
negative enthalpy change and negative entropy
change positive enthalpy change and negative entropy change
negative enthalpy change and positive entropy change

negative enthalpy change and positive entropy change

Explanation:-

According to Gibb's equation:

= Gibbs free energy

= enthalpy change

= entropy change

T = temperature in Kelvin

= +ve, reaction is non spontaneous

= -ve, reaction is spontaneous

= 0, reaction is in equilibrium

Thus when = -ve

= +ve

Reaction is spontaneous at all temperatures.

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