Hudl
Badges: 16
Rep:
?
#1
Report Thread starter 4 years ago
#1
Hey stuck again, can someone help out and explain why you multiply the EDTA mole by 1000/150 I don't get it. Below is my working

Name:  ImageUploadedByStudent Room1427149692.112916.jpg
Views: 115
Size:  190.1 KB


Posted from TSR Mobile
0
reply
mattcandy3
Badges: 6
Rep:
?
#2
Report 4 years ago
#2
The number of moles of EDTA you have calculated corresponds to the number of moles of Ca2+ you have in the solution which in turn effects the moles of dissolved Ca(OH)2

Moles of Ca(2+) = moles of dissolved Ca(OH)2 = 3.325x10^-4 ( which you correctly got)


Now calculate the mass of Ca(OH)2 in grams using moles and MR

That is the mass of Ca(OH)2 in the 150cm3 sample solution


Then calculate the mass of calcium hydroxide that was dissolved that was dissolved in 1dm3
0
reply
Dylann
Badges: 21
Rep:
?
#3
Report 4 years ago
#3
You found the moles correctly but this was in 150cm3. The question is asking for the mass in 1000cm3 so you must find the moles in 1000cm3. To convert from 150cm3 to 1000cm3, you must multiply 150 by (1000/150). The moles are now in 1000cm3 so you can work out mass in 1000cm3

(Original post by Hudl)
Hey stuck again, can someone help out and explain why you multiply the EDTA mole by 1000/150 I don't get it. Below is my working

Name:  ImageUploadedByStudent Room1427149692.112916.jpg
Views: 115
Size:  190.1 KB


Posted from TSR Mobile
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

University open days

  • Cardiff Metropolitan University
    Undergraduate Open Day - Llandaff Campus Undergraduate
    Sat, 19 Oct '19
  • Coventry University
    Undergraduate Open Day Undergraduate
    Sat, 19 Oct '19
  • University of Birmingham
    Undergraduate Open Day Undergraduate
    Sat, 19 Oct '19

Why wouldn't you turn to teachers if you were being bullied?

They might tell my parents (12)
6.42%
They might tell the bully (19)
10.16%
I don't think they'd understand (32)
17.11%
It might lead to more bullying (70)
37.43%
There's nothing they could do (54)
28.88%

Watched Threads

View All