x Turn on thread page Beta
 You are Here: Home >< A-levels

1. KOH CONC is 0.032 Volume added is 40cm3
Propanoic acid conc is 0.024 volume added is 25cm3

kW is 1.0x10-14

Calculate the pH
2. (Original post by Needhelpasap)
KOH CONC is 0.032 Volume added is 40cm3
Propanoic acid conc is 0.024 volume added is 25cm3

kW is 1.0x10-14

Calculate the pH
By the sounds of it, it looks like a stoichiometry style question. Im guessing form an equation with the two chemicals, find the conc of water, and then use the kw equation to find OH ions and do the log of that
3. (Original post by Needhelpasap)
KOH CONC is 0.032 Volume added is 40cm3
Propanoic acid conc is 0.024 volume added is 25cm3

kW is 1.0x10-14

Calculate the pH

Sorry ignore my last answer. Okay formulate an equation find the initial number of moles and do stoichiometry to find the moles of the product. Then use n=cxv but the volume is the two volumes added together as the two chemicals have been mixed. Then you will know OH ions then find H ions from kW and do LOg for ph
4. (Original post by hasan6091)
Sorry ignore my last answer. Okay formulate an equation find the initial number of moles and do stoichiometry to find the moles of the product. Then use n=cxv but the volume is the two volumes added together as the two chemicals have been mixed. Then you will know OH ions then find H ions from kW and do LOg for ph
Thank you! I got an answer of 13.96 is that right?
5. (Original post by Needhelpasap)
Thank you! I got an answer of 13.96 is that right?
For a hydroxide that sounds correct
6. Thank you!
How how would I answer this question -

The yeild is 78%
Mass of sodium P I's 2.5 tonnes
The molar mass iis 116
The molar mass of aspirin is 180 calculate the mass of asprin produced

(Original post by hasan6091)
For a hydroxide that sounds correct
7. (Original post by Needhelpasap)
Thank you!
How how would I answer this question -

The yeild is 78%
Mass of sodium P I's 2.5 tonnes
The molar mass iis 116
The molar mass of aspirin is 180 calculate the mass of asprin produced
Calculate moles of Na im guessing its 1:1 ratio, then find the mass of aspring and find 78 percent of the value
8. (Original post by hasan6091)
Calculate moles of Na im guessing its 1:1 ratio, then find the mass of aspring and find 78 percent of the value
Thank you!!!!!!!!! .
9. (Original post by Needhelpasap)
Thank you!!!!!!!!! .
I've not got the marks heme for this question. Can u please tell me if my answers are right?

For Ii. I got -201.7
For iii I got -563.7

Thank you!!!
10. (Original post by hasan6091)
Calculate moles of Na im guessing its 1:1 ratio, then find the mass of aspring and find 78 percent of the value
Click image for larger version. Name: image.jpg Views: 0 Size: 101.1 KB ID: 495021 I've not got the marks heme for this question. Can u please tell me if my answers are right?For Ii. I got -201.7 For iii I got -563.7Thank you!!!
11. is this ocr a2?

Posted from TSR Mobile
12. (Original post by Needhelpasap)
I've not got the marks heme for this question. Can u please tell me if my answers are right?

For Ii. I got -201.7
For iii I got -563.7

Thank you!!!
Formation is products - reactants
Entropy should be in a data sheet

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: January 17, 2016
Today on TSR

### Negatives of studying at Oxbridge

What are the downsides?

Poll

## All the essentials

### Student life: what to expect

What it's really like going to uni

### Essay expert

Learn to write like a pro with our ultimate essay guide.

### Create a study plan

Get your head around what you need to do and when with the study planner tool.

### Resources by subject

Everything from mind maps to class notes.

### Study tips from A* students

Students who got top grades in their A-levels share their secrets