1. Write a SOP (standard operating procedure) for doing a titration
Bell Work
Write a SOP (standard operating procedure) for doing a titration
Do not use your books Hints – diagram, use known/unknown/ tips

2. ASE Presentation for New Users
Big Picture
Assessment at AS
Unit F331
Chemistry for Life
Unit F332
Chemistry of Natural Resources
Unit F333
Chemistry in Practice (internal assessment)
Elements of Life
Developing Fuels
Elements from the Sea
The Atmosphere
Polymer Revolution
Five practical skills
15% of A level
25% of A level
10% of A level
Written paper
1 hr 15 min
Written paper (one question on an ‘Advance Notice’ passage)
1 hr 45 min
Internal assessment of skills using materials and mark schemes provided by OCR

3. CI p371

4. Content Process Benefit
Learning Outcomes
Content Process Benefit
Skill of carrying out a titration
Calculate unknowns and percentage uncertainty
Carry out a titration
Help in 10% of AS grade!

5. ES4.1 Activity Carry out titration Put your results on the board
Use the booklet to help write your results

6. The question:
10.0 cm3 of a solution of potassium hydroxide was titrated with a 0.10 M solution of hydrochloric acid cm3 of the acid was required for neutralization. Calculate the concentration of the potassium hydroxide solution.
Step 1
Write down everything you know from the question. I put the one we know most about on the left
Hydrochloric Acid                                 Potassium hydroxide
Volume used = 13.5 cm3                     Volume used = 10.0 cm3
Concentration = 0.10M                         Concentration = TBD
TBD to be determined

7. Step 2
Write the BALANCED equation (or as much as you know about it).
 HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
This is necessary to check out the ratios of reactants – in this case 1:1 so we don’t have to worry about any ratios.
Step 3
Calculate the Number of Moles used of the reactant you know most about. In this case the HCl(aq)
The rule here is ;
Number of Moles = concentration

8. Step 3
Calculate the Number of Moles used of the reactant you know most about. In this case the HCl(aq)
The rule here is ;
Number of Moles = volume × concentration
Never do cm3!

9. Step 4
Work out how many moles of the unknown you have used, this is where you may need to multiply up or down the number of moles, so if 1 mole of HCl needed 2 mol of potassium hydroxide, then at this point you would multiply the number of moles of HCl by 2. In this case this is unnecessary.
Number of moles of HCl = mol
Number of moles KOH = mol – they react in a one to one ratio

10. Step 5
 Work out the concentration of the potassium hydroxide.
Moles of KOH (same as HCl as 1:1) –
Volume (q) 10cm3
Concentration = 0.14 M
Number of Moles = volume × concentration

11. CH3COOH + NaOH  H2O + NaOOCCH3
0.1M NaOH ? CH3COOH
Volume 6cm3 10cm3
Balance equation
No. moles = Vol dm3 x conc.
? = (6/1000) x 0.1Moles dm-3
? = 6 x 104 Moles
1:1 ratio thus 6 x 104 Moles of acid
So Conc = Moles/vol dm3 = 6 x 10 4 / (10/1000)
= Moles dm-3

12. Demonstrate
Deduce the concentration of hydrochloric acid if 20.0cm3 is neutralised by 25.0cm3 of sodium hydroxide at 0.2oo moldm-3?

13. Carry out a titration? Confident with procedure?
Review
Carry out a titration?
Confident with procedure?
Confident with calculations?
What to do if you’re not?

14. Home Learning
Best Choice – Salters A level / ES Formula, equations, amount / Titrations and titration calculations
Next lesson is halogen production conference – have poster with you and all qs
+ ready to speak