Example 16.3b: Predicting the Sign of ∆S

Predict the sign of the enthalpy change for the following processes. Give a reason for your prediction.

[a]
\(\ce{NaNO3(s)}\)\(\ce{->}\)\(\ce{Na}\)\(\ce{ + }\)\(\ce{(aq)}\)\(\ce{ + }\)\(\ce{NO3-(aq)}\)\(\ce{ }\)

[b]
\(\ce{ }\)       the freezing of liquid water

[c]
\(\ce{CO2(s)}\)\(\ce{->}\)\(\ce{CO2(g)}\)\(\ce{ }\)

[d]
\(\ce{CaCO(s)}\)\(\ce{->}\)\(\ce{CaO(s)}\)\(\ce{ + }\)\(\ce{CO2(g)}\)\(\ce{ }\)