EASY
AS and A Level
IMPORTANT
Earn 100

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

NH4NO3sN2Og+2H2Og

Values for

G in kJ mol-1;H2Ol=-273.2N2Og=+104.2NH4NO3=-184.0.

Important Questions on Entropy and Gibbs Free Energy

EASY
AS and A Level
IMPORTANT

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

2Mgs+O2g2MgOs

Values for

G in kJ mol-1;MgOs=-569.4Mgs=0O2g=0.

EASY
AS and A Level
IMPORTANT

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

C3H8g+5O2g3CO2g+4H2Ol

Values for

G in kJ mol-1;CO2g=-394.4H2Ol=-273.2O2g=0C3H8g=-23.4.

EASY
AS and A Level
IMPORTANT

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

3 Mgs+Fe2O3s3MgOs+2Fes

Values for

G in kJ mol-1;MgOs=-569.4Fe(s)=0Mgs=0Fe2O3s=-742.2.

EASY
AS and A Level
IMPORTANT

Calculate the Gibbs free energy for the following reaction and state. Giving a reason for the position of equilibrium for the reaction.

Sns+Pb2+aqSn2+aq+PbsSn2+aq+2e-Sns; E=-0.14 VPb2+aq+2e-Pbs; E=-0.13 V

EASY
AS and A Level
IMPORTANT

Calculate the Gibbs free energy for the following reaction and state. Giving a reason for the position of equilibrium for the reaction.

Fe3+aq+AgaqFe2+aq+Ag+aqFe3+aq+e-Fe2+; E=+0.77 VAg+aq+e-Agaq; E=+0.80 V

EASY
AS and A Level
IMPORTANT

Calculate the Gibbs free energy for the following reaction and state. Giving a reason for the position of equilibrium for the reaction.

Ces+Al3+aqCe3+aq+AlsCe3+aq+3e-Ces; E=-2.33 VAl3+aq+3e-Als; E=-1.66 V
EASY
AS and A Level
IMPORTANT

When ethanol undergoes combustion, carbon dioxide and water are formed.

C2H5OHl+3O2g2CO2g+3H2Ol.

Calculate the standard entropy change for this reaction.

Values for

 Sin J K-1mol-1;C2H5OHl=160.7,O2g=205.0,CO2g=213.6,H2Ol=69.90.

EASY
AS and A Level
IMPORTANT

Calculate the Gibbs free change for the given reaction.

When ethanol undergoes combustion, carbon dioxide and water are formed.

C2H5OHl+3O2g2CO2g+3H2Ol.

Values for

 Gfin kJ mol-1:C2H5OHl=-174.9,O2g=0,CO2g=-394.4,H2Ol=-237.2.