Revision WS-1 MS.pdf Chemistry states of matter

States of matter

1. GuidanceNotesAO ElementMarksAnswerQuestion
2step 4
evaporate filtrate to point of
crystallisation / evaporate some
1
of the water and leave /
evaporate to form saturated
solution (1)
step 6
dry crystals on filter paper / dry
crystals in drying oven (1)
1neutralisation2
2from red / pink (1)3(a)
to yellow (1)
1pH 143(b)
2magnesium chlorideAND
hydrogen (1)
4(a)
bubbles/effervescenceOR
magnesium gets smaller /
disappears (1)
2magnesium chloride AND
carbon dioxide AND water (1)
4(b)
1lilac5
/- Mark Scheme

2. GuidanceNotesAO ElementMarksAnswerQuestion
1(NH
4
)
2
SO
4
6
1limewater7
3M1rate increasesandparticles
have more energy (1)
8
M2more collisions (between
particles) occur per second / per
unit time (1)
M3more of the particles /
collisions have energy equal to
or above the activation energy
(1)
or
more of the particles / collisions
have sufficient energy to react
or
a higher percentage / proportion
/ fraction of collisions (of
particles) are successful / have
energy equal to or above
activation energy
2(a substance which) increases
the rate of a reaction (1)
9(a)
remains unchanged OR
unaffected OR without changing
mass (1)
/- Mark Scheme

3. GuidanceNotesAO ElementMarksAnswerQuestion
49(b)
decreases (1)increases (1)
decreases (1)decreases (1)
1reversible reaction10(a)
178 (%)10(b)
111(a)
M1increases (1)
M4increases (1)M2decreases (1)
M3increases (1)
1forward reaction is
endothermic
11(b)
2M1white (1)12(a)
M2to (light) blue (1)
15H
2
O12(b)
1heating12(c)
/- Mark Scheme

4. GuidanceNotesAO ElementMarksAnswerQuestion
2M1boiling point (1)12(d)
M2is 100 °C
OR
M1freezing point (1)
M2is 0 °C (1)
1reactants on top left horizontal
lineANDproducts on bottom
right horizontal line
13
1exothermic14
1reaction which absorbs thermal
energy / reaction which absorbs
heat
15
[Total: 35]
/- Mark Scheme