Determine the sign (+) or (-) of ΔSo for the following reactions at standard temperature:?

Question

H2O (l) --H2O ( g )
CaCO3 ( s ) -- CaO( s ) + CO2( g )
NH4 NO3 ( s ) + H2O( l )--- NH4 + ( aq ) + NO3- ( aq )

Answer 1

To solve these kinds, you usually have to refer to the appendix at the end of your textbook. Find the values of delta S by (sum of S of the products - sum of S of the reactants).

Answer 2

H2O (l) --H2O ( g ) +ve
CaCO3 ( s ) -- CaO( s ) + CO2( g ) +ve
NH4 NO3 ( s ) + H2O( l )--- NH4 + ( aq ) + NO3- ( aq ) +ve