1 A reactant -its concentration decreases with time.
2 1.3×10-3 mol dm-3 s-1 to2sf
3
The rate of reaction after 300 seconds.
4 That at time 0 seconds, the gradient will be steeper than that at time 600 seconds.
5 The rate of reaction at the beginning is greatest as the concentration of’ reactants is greatest here a.
1Rate= k[A][B][C]2
2
Br03-(aq) + 5Br-(aq) + (aq) -.3Bra (aq)+ 3H20(l)
Brornate ions bromide ions hydrogen ions bromine Water
a
i BrO3–(aq)
1
ii Br–(aq)
1
iii H+(aq)?
2
b
i BrO3–(aq)
Double
ii Br–(aq)
Double
iii H+(aq)?
Quadruple
c
i BrO3–(aq)
ii Br–(aq)
5
iii H+(aq)
6
iv Br2(aq)
3
v H2O(1)
3
d
dm9 mol-3 s-1
3
The rate constant
b
i L
2
ii M
0
iii N
0
iv H’?
1
c
3
d
dm6 mol-2 s-1
A catalyst
4
It is impossible to tell without experimental data.
nd then decreases as reactants are used up.
1
a i A
1
ii B?
2
b 3
c
27 mol dm-3s-1
d
Rate= k[A][B]2
e No, other species might be involved that have not been investigated.
1
a 300 K
36 in 1019 molecules
b 310 K
13 in 10 18 molecules
2
Plot 103.75 kJ mol·1
1
a B
b F
c Step ii
Banner 21 (a
(i)2 or two or second or [E]2
(ii)
1 or one or first or [F]1 or [F]
(b
i k = 8.6 × 10-4 / ((3.8 × 10-2)2 × (2.6 × 10-2))
= 22.9 (Allow 22.9 – 24 after correct rounding)
Mol-2 dm6 s-1
ii 6.8(2) × 10-3 (mol dm-3 s-1)
2 2P(g) + 2Q(g) —► R(K) +S(g)
(a)
Experiment 2 4.5 ×10-4
Experiment 3 4.5 ×10-3
Experiment 4 0.043 OR 4.3 ×10-2
OR 0.044 OR 4.4 ×10-2
(b) k = 5.0 × 10-5 / ((2.5 × 10-2)2 × (1.8 × 10-2))
= 4.4(4) (allow 40/9)
Mol-2 dm6 s-1.
.
Banner 3Disclaimer: I have tried by level best to provide the answers and video explanations to the best of my knowledge. All the answers and notes are written by me and if there is any similarity in the content then it is purely coincidental. But this is not an alternative to the textbook. You should cover the specification or the textbook thoroughly. This is the quick revision to help you cover the gist of everything. In case you spot any errors then do let us know and we will rectify it. References: BBC Bitesize AQA GCSE Science Kerboodle textbook Wikipedia Wikimedia Commons Join Our Free Facebook Group : Get A* in GCSE and A LEVEL Science and Maths by Mahima Laroyia: https://www.facebook.com/groups/expertguidance.co.uk/ For Free Tips, advice and Maths and Science Help