Advanced Higher Chemistry 2018-19 Watch

_nim1
Badges: 15
Rep:
?
#81
Report 2 weeks ago
#81
Name:  image.jpg
Views: 18
Size:  117.9 KB
The KOH is diluted as 40cm3 is added so you need to find the new concentration if that makes sense
(Original post by lois_____)
Anyone know how to get part a) the k+ Conc
Last edited by _nim1; 2 weeks ago
0
reply
lois_____
Badges: 7
Rep:
?
#82
Report 2 weeks ago
#82
Thank you!! Why are you putting 20/60 tho ?
(Original post by _nim1)
Name:  image.jpg
Views: 18
Size:  117.9 KB
The KOH is diluted as 40cm3 is added so you need to find the new concentration if that makes sense
0
reply
lois_____
Badges: 7
Rep:
?
#83
Report 2 weeks ago
#83
Aw I see now tyty
(Original post by lois_____)
Thank you!! Why are you putting 20/60 tho ?
1
reply
_nim1
Badges: 15
Rep:
?
#84
Report 2 weeks ago
#84
20cm3 of KOH divided by the new total volume of 60cm3 then multiply that by the concentration. That’s how you find the concentration of solutions that are diluted : )
(Original post by lois_____)
Thank you!! Why are you putting 20/60 tho ?
0
reply
Mhussain01
Badges: 5
Rep:
?
#85
Report 2 weeks ago
#85
For the same question how do you find the H+ conc?
(Original post by _nim1)
20cm3 of KOH divided by the new total volume of 60cm3 then multiply that by the concentration. That’s how you find the concentration of solutions that are diluted : )
0
reply
_nim1
Badges: 15
Rep:
?
#86
Report 2 weeks ago
#86
Find the ph using ph= pka - log[acid]/[salt]
Then use the equation ph= -log[H+] just rearranging it
(Original post by Mhussain01)
For the same question how do you find the H+ conc?
0
reply
A_Ch
Badges: 11
Rep:
?
#87
Report 2 weeks ago
#87
Does anyone have the answers to yesterday's scholar session?
0
reply
Labrador99
  • Volunteer Team
Badges: 21
Rep:
?
#88
Report 2 weeks ago
#88
(Original post by A_Ch)
Does anyone have the answers to yesterday's scholar session?
SCHOLARuk are you able to help?
0
reply
lois_____
Badges: 7
Rep:
?
#89
Report 2 weeks ago
#89
Anyone know how to do q4 ?
Attached files
0
reply
chic geek
Badges: 8
Rep:
?
#90
Report 2 weeks ago
#90
thank you so much x
0
reply
chic geek
Badges: 8
Rep:
?
#91
Report 2 weeks ago
#91
how did you get 0.66 for the concentration of salt?
(Original post by _nim1)
Find the ph using ph= pka - log[acid]/[salt]
Then use the equation ph= -log[H+] just rearranging it
0
reply
chic geek
Badges: 8
Rep:
?
#92
Report 2 weeks ago
#92
can anyone help me with these?


5. When one mole of phosphorus pentachloride was heated to 523K in a closed vessel, 50% dissociated as shown
PCl5(g) -> PCl3(g) + Cl2(g)
How many moles of gas were present in the equilibrium mixture?
A 0·5 B 1·0 C 1·5 D 2·0


7. Which of the following 0.01 mol l−1 aqueous solutions has the highest pH value?
A Sodium fluoride
B Sodium benzoate
C Sodium propanoate
D Sodium methanoate


10. Which of the following reactions would show the greatest decrease in entropy?
A H2(g) + F2(g) → 2HF(g)
B KNO3(s) → KNO2(s) + 1/2 O2(g)
C CO3^2−(aq) + 2H+(aq) → H2O(l) + CO2(g)
D CO3^2−(aq) + CO2(g) + H2O(l) → 2HCO^3−(aq)


20. Which of the following compounds would liberate one mole of hydrogen gas if one mole of it reacts with two moles of sodium?
A C2H5OH
B HOCH2CH2OH
C CH3COOH
D CH3CHO
0
reply
A_Ch
Badges: 11
Rep:
?
#93
Report 2 weeks ago
#93
For question 20, I think the answer is B because the reaction between a metal and an alcohol is an elimination reaction which removes the one hydrogen atom to make an alkene and if there are 2 moles of sodium then you would be looking for the molecule with 2 hydroxyl functional groups. Thats what I would do.
0
reply
A_Ch
Badges: 11
Rep:
?
#94
Report 2 weeks ago
#94
Can I get help on these questions please.
0
reply
lois_____
Badges: 7
Rep:
?
#95
Report 2 weeks ago
#95
Scholar answers
Attached files
1
reply
A_Ch
Badges: 11
Rep:
?
#96
Report 2 weeks ago
#96
Thank you!!
(Original post by lois_____)
Scholar answers
0
reply
_nim1
Badges: 15
Rep:
?
#97
Report 2 weeks ago
#97
The concentration of the salt is 0.333 from the answer to part a)
The concentration of the acid is 0.667, found by 40/60 multiplied by the concentration which is 1
(Original post by chic geek)
how did you get 0.66 for the concentration of salt?
0
reply
lois_____
Badges: 7
Rep:
?
#98
Report 2 weeks ago
#98
I think for the 2nd one, to get the right chloride ion concentration you’d need a total volume of 100ml but you’ve already got 25ml there so 100-25 = 75ml so wld need to be diluted by 75ml of water. So 75ml is the answer I would think
(Original post by A_Ch)
Can I get help on these questions please.
0
reply
lois_____
Badges: 7
Rep:
?
#99
Report 2 weeks ago
#99
Ligands attach through electron pairs

(Original post by A_Ch)
Can I get help on these questions please.
0
reply
A_Ch
Badges: 11
Rep:
?
#100
Report 2 weeks ago
#100
Thanks, I thought too much about this question and used so many calculations to get an answer. This was actually and made sense now.
(Original post by lois_____)
I think for the 2nd one, to get the right chloride ion concentration you’d need a total volume of 100ml but you’ve already got 25ml there so 100-25 = 75ml so wld need to be diluted by 75ml of water. So 75ml is the answer I would think
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
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

University open days

  • Arts University Bournemouth
    Art and Design Foundation Diploma Further education
    Sat, 25 May '19
  • SOAS University of London
    Postgraduate Open Day Postgraduate
    Wed, 29 May '19
  • University of Exeter
    Undergraduate Open Day - Penryn Campus Undergraduate
    Thu, 30 May '19

How did your AQA GCSE Physics Paper 1 go?

Loved the paper - Feeling positive (401)
30.63%
The paper was reasonable (514)
39.27%
Not feeling great about that exam... (225)
17.19%
It was TERRIBLE (169)
12.91%

Watched Threads

View All