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Year 13 Entropy

Last updated about 1 year ago
22 questions
Note from the author:
Edexcel chemistry entropy using system and surroundings
1

1

Hint MP = 801oC
Boiling point = 1413oC

5
Explain why the entropy of the system increases when sodium chloride dissolves in water. (2)
In the solid / lattice, the ions are __________ (1) But in the solution the ions are ___________ /more dispersed / more spread out/ more random (so entropy has increased) (1)
(Dissolving results in) an increase in the number of moles of particles and from ________ to ________ / NaCl → Na+ + Cl−
(1) The _____________ bonds between the water molecules are disrupted
Other Answer Choices:
one
hydrogen
fixed
mobile
two
1
(High) positive value is expected because:
______ moles → _______ moles.
(two) ___________ → ________ and/or liquid (+ one solid)
Entropy of the surroundings for an endothermic reaction is _____________ (1)
The reaction is feasible with the total entropy being _____________ (so entropy of the system has to be a large enough positive value for this to be true).
Other Answer Choices:
3
negative
13
solids
positive
gas
1

∆Sɵ system = (sign) _______ _______ JK-1mol-1
1
sign _______
value = _______ kJ mol-1
1
sign= _______
value = _______ JK-1mol-1


sigh = _______
value = _______ J K -1 mol-1
1

∑Sɵ (products) = + _______
∑Sɵ (reactants) = + _______
∆Sɵ system = _______
1
(iii) Give two reasons why the positive sign of your answer to (a)(ii) is as you would expect.
more moles of _____________ than ______________ (3 moles → 13 moles)
Two solids in the ______________ → a gas / a liquid (+ 1 solid) in the _____________
Other Answer Choices:
products
reactants
1
sign _______
value = _______ J mol-1 K-1



sign = _______
value = _______
1
∆Sɵ _________________ becomes less negative (smaller in MAGNITUDE (because you are dividing −∆H by a larger T)
∆Sɵ ___________ / ∆H are not (significantly) affected by a change in temperature.
∆Sɵ __________ increases
Other Answer Choices:
total
system
surroundings
1
_______ (give your value as a decimal to 4 s.f.)
1
Barium hydroxide will ___________ (very) soluble / will be sparingly soluble
and K value suggests that the equilibrium lies to the ______________ side / reactants
OR K << 1 so ______________ predominant
Other Answer Choices:
products
be
right-hand
left-hand
not be
reactants
1
M1: Hydroxides get _________ soluble as you descend Group 2 (1)
M2: ∆Sɵ total gets _________negative as you go from Ca(OH)2 to Ba(OH)2
Other Answer Choices:
more
more
less
1
_______ J mol−1 K−1 Note the units are J not kJ
2

________ and solid react to to form __________
There are fewer ways of arranging particles in a __________ than a ________.
________ mol(es) of reactant forming ________ mole of product.
__________ mol(es) of products than reactants
Other Answer Choices:
solid
one
Two
Fewer
gas
3
Give the formula to be used
________ = ________ + ________
Other Answer Choices:
1
Sign = _______
value = _______ J mol−1 K-1
1
value = - _______ kJmol−1 Note the units
1

1


sign _______
value _______ kJmol−1

sign _______
value _______ J mol−1 K−1 Note the units




sign = _______
value = _______ J mol−1 K−1
1
Decrease in T: _____________ is not (significantly) changed.
___________ or (−∆H/T) is more positive.
makes __________ more positive
Other Answer Choices:
∆Stot
∆Ssystem
∆Ssurr