Page 174 - Chemistry

 Phenolphthalein inidicator
 Methyl orange indicator

You are required to:
(a) Standardize HCl solution M
(b) Determine the value of X in Na 2CO 3. XH 2O
Procedure I
3
Fill the burette with HCl solution M. pipette 25cm of NaOH solution N into a conical flask.
Add 2 drops of phenolphthalein indicator and titrate until you obtain a permanent colour change.
Record your results in table I below. Repeat the titration two more times and complete the table.
Table 1
Titration 1 2 3
3
Final burette reading (cm )
3
Initial burette reading (cm )
Vol. of solution M used
3
(cm )

(i) What is the average volume of solution M used
(ii) Calculate the number of solution N used
(iii) Write the equation for the reaction that took place
(iv) Calculate the number of moles of solution M in the titre volume
(v) Find the concentration of solution M in moles per litre
(vi) Calculate the concentration of solution M in grams per litre
Procedure II
3
Fill the burette with HCL solution M. pipette 25cm of solution P into a conical flask.
Add 2 drops of methyl orange indicator and titrate against solution M. repeat the titration
two more times and complete the table.
Table II
Titration 1 2 3
Final burette reading
Initial burette reading
3
Vol. of solution M used (cm )

(a) What is the average volume of solution M used?
(b) Calculate the moles of HCl in the titre volume of solution M
(c) Write the equation for the reaction that took place
(d) Calculate the moles of solution P used
(e) Find the concentration of Na 2CO 3. XCH 2O in solution P in moles per litre
(f) State the concentration of Na 2CO 3.XH 2O in solution P in grammes per litre
(g) Find the R.F.M of Na 2CO 3.XH 2O
(h) The value of X in Na 2CO 3. XH 2O

2. You are provided with;
- 1.0M potassium iodide
- 1.0M lead (II) nitrate

You are required to use the two to determine the height of precipitate and the volume
of Pb(NO 3) 2 solution used.

Procedure
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