Entropy - exam practice

H₂O_(s) ➔ H₂O_(l)

Hg_(l) ➔ Hg_(g)

H₂O_(l) + HCl_(g) ➔ H₃O⁺_(aq) + Cl^-_(aq)

C(graphite) ➔ C(diamond)

change W never occurs

change X could be the reaction of a solid carbonate with an acid

change Y could be a precipitation reaction

change Z could be the condensation of a gas to a liquid

-219.1

-88.5

+88.5

+219.1

the reaction is always feasible

the reaction is feasible above a certain temperature

the reaction is feasible below a certain temperature

the reaction is never feasible

enthalpy increases and entropy decreases

enthalpy decreases and entropy increases

enthalpy decreases and entropy decreases

enthalpy increases and entropy increases

the formation of products is favoured

the reaction is spontaneous

the reaction is at equilibrium

the formation of reactants is favoured

if ΔH < 0, the reaction is always spontaneous

if ΔS < 0, the reaction can be spontaneous if temperature is high enough

if ΔS < 0, the reaction can be spontaneous if temperature is low enough

if ΔH > 0, the reaction is never spontaneous

ΔG = negative, K < 1

ΔG = positive, K > 1

ΔG = negative, K > 1

ΔG = positive, K < 1

ΔH^⦵ = positive, ΔS^⦵ = negative

ΔH^⦵ = negative, ΔS^⦵ = positive

ΔH^⦵ = positive ΔS^⦵ = positive

ΔH^⦵ = negative, ΔS^⦵ = negative

S = minimum, G = minimum

S = minimum, G = maximum

S = maximum, G = minimum

S = maximum, G = maximum

entropy is higher in the products than in the reactants

K decreases as temperature increases

the forward reaction is more spontaneous below 300 K

equilibrium shifts left as temperature increases

CaCO_3(s) ➔ CaO_(s) + CO_2(g)

N_2(g) + 3H_2(g) ⇌ 2NH_3(g)

3CO_2(g) + 3H₂O_(g) ➔ C₃H_8(g) + 5O_2(g)

SO_2(g) + H₂O_2(l) ➔ H₂SO_4(l)

CaCO_3(s) ➔ CaO_(s) + CO_2(g)

H₂O_(l) ➔ H₂O_(s)

NH_3(g) + HCl_(g) ➔ NH₄Cl_(s)

C₂H₅OH_(l) + SOCl_2(l) ➔ C₂H₅Cl_(l) + SO_2(g) + HCl_(g)

CaCO_3(s) ➔ CaO_(s) + CO_2(g)

H₂O_(l) ➔ H₂O_(g)

N_2(g) + 3H_2(g) ⇌ 2NH_3(g)

2S₂O₃^2-_(aq) + I_2(aq) ➔ S₄O₆^2-_(aq) + 2I^-_(aq)

$\mathrm{\Delta }{S}_{system}-\frac{\mathrm{\Delta }H}{T}$

$\mathrm{\Delta }{S}_{surroundings}+\frac{\mathrm{\Delta }H}{T}$

$\mathrm{\Delta }{S}_{surroundings}-\frac{\mathrm{\Delta }H}{T}$

$\mathrm{\Delta }{S}_{system}+\frac{\mathrm{\Delta }H}{T}$