CLS 231 Exam questions
Q1- Fill in the blanks: (3 marks)
1- An elevation of the .....................may be observed in compensated respiratory acidosis and metabolic alkalosis.
2- .......................... is used to separate mixtures of two liquids with different boiling points.
3-......................... and .......................... Interfere with biocarbonate procedure.
4- Complexometric titration is useful for the determination of different ........................., in solution.
5- Electron donor in complexometric titration is called...................................
Q2- List the following: (2 marks)
1- Two purposes of using back titration.
2- Two components of complexometric titration.
Q3- Put either (T) true or (F) False: (3 marks)
1-
Primary standard is hygroscopic and should be stable to drying. ( )
2-
Sodium tungstate helps in precipitation of protein in the preparation of the sample.( )
3-
The chloride ions will be complexed after the mercuric ions complex with diphenyl carbazone.( )
4-
KHP is not highly pure( )
5-
Equivalence point involves color change.( )
6-
An indicator is a chemical that changes PH for the solution. ( )
Q4- Choose the correct answer :(3 marks)
1) this graph is an example of:
a) back titration
b) strong acid or base against strong base/acid titrations
c) complexometric titration
d) idometric titration.
2) …………………..is an indicator gives violet-blue color at the end point.
a) Phenolphthalein.
b) Potassium phthalate
c) Diphenylcarbazone
3) …………………….is a primary standard.
a) Potassium acid phthalate
b) NaOH
c) HgCl 2
Q5- Calculate the concentration of calcium titer and unknown calcium ,in molarity, in which 7 ml of CaCo3 was titrated with EDTA in the presence of 2 ml of pH 10 buffer followed by addtion of 3 drops of MG-EDTA and 1 drop of EBT indicator.
( used CaCo3 mass was 0,6 g/L , EDTA volume at end point was 5 ml in both standardisation and analysis, Ca MW = 40,08 mg, CaCO3 MW= 100,09 mg.
(1 mark)
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