# Science Stuff

## Science Stuff

• Submitted By: stevexxx
• Date Submitted: 04/26/2011 6:36 PM
• Category: Science
• Words: 264
• Page: 2
• Views: 246

JESUS CHRIST - SAVIOUR AND LORD
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Cape Chemistry Unit 1 Worksheet Date ………………...

1. Calculate the hydroxide ion concentration in
a. an acid solution which has a concentration of hydrogen ions of 0.10 mol dm-3.
b. 0.010 mol dm-3 HCl
c. 0.10 mol dm-3 H2SO4

2. Calculate the hydrogen ion concentration in
a. 0.010 mol dm-3 KOH
b. 0.050 mol dm-3 Ba(OH)2

3. The self-ionisation of water is an endothermic process
2 H2O(l) [pic] H3O+ (aq) + OH- (aq) ΔH = +6.5 kJ mol-1
Is the concentration of hydrogen ions in pure water at 400C less than or greater than the value at 250C? Explain your answer.

4. Calculate the pH of the hydrochloric acid solutions from the given concentrations/ mol dm-3 :
0.10, 0.010, 0.0010, 0.00010.

5. Calculate the pH of the ethanoic acid solutions from the given concentrations/ mol dm-3 :
0.10, 0.010, 0.0010, 0.00010. Ka ethanoic acid is 1.7 x 10 -5 mol dm-3.

6. Comment on the pH values of the hydrochloric and ethanoic acids.

7. Calculate the hydrogen ion concentration in solutions with pH 9.0, 2.0, 9.2, 2.632.

8. Calculate the pH of a 0.100 mol dm-3 iodic (V) acid, HIO3 , at 25 0 C. Ka = 0.17 mol dm -3.

9. The pH of 5.0 x 10 -3 benzoic acid solution C6H5COOH, is 3.28 at 250C. Calculate the value of the dissociation constant at this temperature.