Amangee
Badges: 4
Rep:
?
#1
Report Thread starter 4 years ago
#1
Hi,

Could you please help me out with these questions, have asked my teachers for help but to no avail. Thanks

8 The gaseous first order reaction, A o B + C, was found to have a half-life of 20*s
when the initial pressure of A was 2 atm.
When the initial pressure of A is increased to 4 atm, the half-life is
A 10 s
B 20 s
C 40 s
D 400 s
(Total for Question 8 = 1 mark)
Spoiler:
Show
B



9 The equation for the equilibrium between nitrogen and oxygen may be written in two ways.
N2 (g) + O2 (g) = 2NO(g) Equilibrium constant K1
½N2(g) + ½O2 (g) U NO(g) Equilibrium constant K2
The standard enthalpy change, H for the reaction as shown in the first equation is +180 kJ mol–1.
(a) What is the standard enthalpy change for the reaction as shown in the second equation?
A +45 kJ mol–1
B +90 kJ mol–1
C +180 kJ mol–1
D +360 kJ mol–1
Spoiler:
Show
B




(d)Find pH of The mixture formed when 25 cm3 of 2 mol dm–3 sodium hydroxide solution is added to 50 cm3 of 2 mol dm–3 ethanoic acid, for which Ka = 1.7 × 10–5 mol dm–3.
A 2.2
B 2.5
C 4.5
D 4.8
Spoiler:
Show
D


Calcium carbonate decomposes at high temperature to form calcium oxide and
carbon dioxide:
CaCO3(s) CaO(s) + CO2(g)
Calcium carbonate is thermodynamically stable at room temperature because for this reaction
A the activation energy is high.
B the enthalpy change, H, is positive.
C entropy change of the system (Ssystem) is positive.
D entropy change of the system (Ssystem) is negative.
Spoiler:
Show
B




20) The hydride ion H- is a strong reducing agent, a good nucleophile and a strong base. Which of the following changes could NOT be bought about by the ion.

A)CH3CHO to CH3CH2OH
B) C2H5BR to C2H6
C) CH2=CH2 to C2H6
D) CH3COOH to CH3COO-

Spoiler:
Show
C


http://www.thestudentroom.co.uk/atta...1&d=1432550656
Answer is
Spoiler:
Show
B for the naoh and ammonia one



http://www.thestudentroom.co.uk/atta...1&d=1432550772
Spoiler:
Show
Colourless to (pale) pink or colourless to purple
Attached files
0
reply
Amangee
Badges: 4
Rep:
?
#2
Report Thread starter 4 years ago
#2
bump? anyone?
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

What factors affect your mental health the most right now? (select all that apply)

Lack of purpose or routine (277)
15.42%
Uncertainty around my education (281)
15.65%
Uncertainty around my future career prospects (178)
9.91%
Isolating with family (127)
7.07%
Lack of support system (eg. Teachers, counsellors) (80)
4.45%
Lack of exercise/ability to be outside (150)
8.35%
Loneliness (177)
9.86%
Financial worries (74)
4.12%
Concern about myself or my loved ones getting ill (165)
9.19%
Exposure to negative news/social media (128)
7.13%
Lack of real life entertainment (eg. cinema, gigs, restaurants) (159)
8.85%

Watched Threads

View All