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NECO Chemistry Practical 2019 Questions Released [Answers]

2019 NECO Chemistry Practical Questions and Answers is Out.

See Neco chemistry practical 2019 questions from this post. The National Examination Council (NECO) 2019 Chemistry practical paper for SSCE will hold on Thursday 13th June from 10:00am to 12noon.

Here, we will be providing you with the Neco Chemistry practical past questions and materials that will be used for Examination preparation.

neco chemistry practical answers

Neco Chemistry Practical Question 2019:

1. C is a mixture of two salts.  Carry out the following exercises on C.  Record your observations and identify any gas(es) evolved.  State the conclusion drawn from the result of each test.

Put all of C into a boiling tube and add about 5cm3 of distilled water.  Stir thoroughly and filter.  Keep both the residue and the filtrate. To about 2 cm3 of the filtrate, add few drops of Pb(NO3)2(aq)‑Boil the mixture and then allow to cool.
(i) Put the residue in a test tube and add dilute HNO3. Shake the mixture and divide the      solution into two portions.
(ii) To the first portion from (c)(i), add NaOH(aq) in drops and then in excess.
(iii) To the second portion from (c)(i), add aqueous ammonia in drops and in excess.

2. F is a mixture of two compounds. Carry out the following exercises on F. Record your observations and identify any gas(es) evolved. State the conclusion drawn from the results of each test. Put all of F into a beaker or a boiling tube and add about 10 cm3 of distilled water. Stir the mixture thoroughly and filter. Keep both the filtrate and the residue.
(i) Divide the filtrate into two portions.
(a) To the first portion, add dilute HNO3  followed byAgNO3(aq).
(b) Add excess NH3(aq) to the resulting mixture.
(ii) To the second portion, add NH3(aq) in drops and then in excess.
Add about 5 cm3  of distilled water to the residue in a test tube.  Boil and allow to cool.  Add few drops of iodine solution.

ANS:

TEST OBSERVATION INFERENCE
a) F + water, stirred mixture
and filtered
Partly dissoves/soluble Colourless filtrate
White residue
F contains soluble and insoluble salts
b) (i)  I

 

II

Filtrate + dil HNO3

+ Ag NO3(aq)

Mixture in (b)(i)  +
excess NH3 solution

No visible reaction

White precipitate formed

 

Precipitate dissovles

 

Cl- present

 

Cl- confirmed

b)(ii) Filtrate + HN3(aq) in drops

 

then in excess

White gelatinous precipitate

 

Precipitate dissovles

Zn+2 or A13+
may be presentZn2+ confirmed
c) Residue + water + heat

allow to cool + iodine solution

Jelly-like paste is formed

Dark/deep blue/blue black colouration is obtained

 

Starch is confirmed

Regular Specimen Apparatus for Titration in Chemistry:

This is a complete list of the normal apparatus and reagents for qualitative work including the following with all reagents appropriately labelled to avoid mistake.

  1. Four test tubes
  2. Wash bottle containing distilled/ deionized water
  3. Mathematical table /calculator.
  4. Dilute sodium hydroxide solution
  5. Barium chloride solution
  6. Dilute trioxonitrate (V) acid
  7. Glass rod
  8. Aqueous ammonia
  9. Dilute hydrochloric acid
  10. Silver trioxonitrate (V) solution
  11. Dilute tetraoxosulphate (VI) acid
  12. Filtration apparatus
  13. Spatula
  14. Two boiling tubes.

During NECO Chemistry Practical exam, each candidate should be supplied with the following, where ‘n’ is the candidate’s serial number.

  • 150cm3 of ethanedioic acid (H2C204) solution in a corked flask or bottled labelled ‘An’. These should all be the same containing 4.50g of H2C204 per dm3 of solution.
  • 150cm3 of potassium tetraoxomanganate (VII) solution in a corked flask or bottle labelled ‘Bn’. These should all be the same containing 3.16g of KMnO4 per dm3 of solution.
  • One spatulaful of a uniform mixture of NaCl and ZnCO3 in a specimen bottle labelled ‘Cn’. The components of the mixture should be in the ratio 1:1 by mass.

The details of the 2018 NECO Chemistry practical titration and calculations will be made available to you candidates as soon as it is released. Keep following this page and make sure you bookmark this site for reference purposes.

If you have any questions, endeavour to use the comment box below.


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