WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

2000 WAEC Chemistry Practical (a) Name one laboratory equipment used for (i) keeping salts dry: (ii) converting vapour to liquid during distillation...

Chemistry
WAEC 2000

(a) Name one laboratory equipment used for

(i) keeping salts dry:

(ii) converting vapour to liquid during distillation

(ii) bubbling a gas into a liquid

 

(b) (i) What technique would you use to purify a sample of sodium chloride contaminated with ammonium chloride?

(ii) Given sodium hydroxide solution, outline the procedure you would use to determine whether or not all the ammonium chloride in (b)(i) above had been removed.

 

(c) State what is observed on carrying out each of the following exercises.

(i) Adding few drops of methyl orange indicator to lime juice:

(ii) Adding few drops of concentrated HNO\(_3\) to acidified FeSO\(_4\) solution

(iii) Exposing a fresh precipitate of silver chloride to sunlight for 30 minutes

(iv) Adding zinc dust to dilute CuCl\(_2\) solution;

(v) Adding dilute H\(_2\)SO\(_4\), to Pb(NO\(_3\))\(_2\) solution

 

Your School's Whatsapp Group - Join Us now
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Explanation

(a)(i) desiccator

    (ii) Liebig condenser

   (iii) Delivery tube

 

(b)(i) Sublimation

(ii) Make a small solution of the salt, add NaOH dropwise and then excess. If there is no visible reaction, even when warmed, it indicates that the whole ammonium chloride has sublimed. But if a gas with choking or irritating smell which turns red litmus paper blue is given off then it's the ammonium salt.

 

(c)(i) The colour turns red/ pink

(ii) A brown ring is formed where the HNO\(_3\) gets in contact with the acidified FeSO\(_4\).

(iii) It turns violet and then black

(iv) Copper is deposited.

(v) A white precipitate will be formed.


Report an Error Ask A Question Download App
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

Contributions ({{ comment_count }})

Please wait...

{{ settings.no_comment_msg ? settings.no_comment_msg : 'There are no comments' }}

Quick Questions

Post your Contribution

Please don't post or ask to join a "Group" or "Whatsapp Group" as a comment. It will be deleted. To join or start a group, please click here

{{ quote.posted_by.display_name }}
{{ settings.form_textarea_description }}
 
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Post UTME Past Questions Agent
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Your School's Whatsapp Group - Join Us now
Your School's Whatsapp Group - Join Us now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Post UTME Past Questions Agent
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now