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

Chemistry Past Questions

Clear Selections
Change Subject Post a Question Check Syllabus Study My Bookmarks Past Questions Videos Watch Video Lessons 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
3531

(a)(i) Define heat of neutralization

(ii) Give the reason why copper (II) chloride can be prepared by neutralization, unlike lead (II) chloride.

(b)(i) Describe in outline, the manufacture of trioxonitrate (V) acid by the catalytic oxidation of ammonia, giving equations where appropriate.

(ii) What are the products obtained when sodium tioxonitrate (V) is heated strongly?

 

(c) When powdered magnesium is heated to redness in a stream of nitrogen, magnesium nitride (Mg\(_3\)N\(_2\)) is formed.

(i) Write an equation for the reaction

(ii) Hence, calculate the amount (in mole) of magnesium nitride that can be obtained from 3.0g of magnesium [Mg = 24].

View Answer & Discuss WAEC 1998
3532

(a)(i) What is an electrolyte?

(ii) Classify each of the following as strong electrolyte/weak, electrolyte/non-electrolyte. Potassium chloride; sodium ethanoate, aqueous ammonia; cane sugar

 

(b)(i) Write half-cell equations for the reactions in the Daniel cell .

(ii) Why is the Daniel cell classified as an electrochemical cell?

(iii) Give two other examples of electrochemical cell.

 

(c) Explain the following observations.

(i) Graphite conducts electricity, unlike most non-metals

(ii) In the electrolysis of copper (II) tetraoxosulphate (VI) solution, the blue colour fades with platinum electrodes while the colour intensity is unaffected with copper electrodes (equations required)

(iii) A solution of dry hydrogen chloride in methylbenzene (toluene) does not conduct electricity whereas hydrochloric acid does.

View Answer & Discuss WAEC 1998
3533

(a) List two properties of alpha particles.

(b) X is an element which exists as an isotopic mixture containing 90% of \(^{39}_{19} X\) and 10% of \(^{41}_{19}X\).

(i) How many neutrons are present in the isotope \(^{41}_{19}X\)?

(ii) Calculate the mean relative atomic mass of X.

View Answer & Discuss WAEC 1997
Post UTME Past Questions Agent
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Your School's Whatsapp Group - Join Us now
3534

(a)(i) State the two main processes involved in the manufacture of oxygen from air

(ii) Name the type of chemical bonding which exists between oxygen atoms in a molecule of oxygen

(b) What term is used to describe the relationship between oxygen and ozone (O\(_3\))?

View Answer & Discuss WAEC 1997
3535

 (a) List two industrial uses of concentrated tetraoxosulphate (VI) acid

(b) The diagram below represents the set-up for the electrolysis of dilute tetraoxosulphate (VI) acid. Use it to answer Questions (i) to (iii).

(i) Which letter on the diagram represents the battery?

(ii) Write an equation for the reaction occurring at the cathode

(iii) What product does V represent?

 

View Answer & Discuss WAEC 1997
Start a Free Practice Test
 
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
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now