Search SchoolNGR

Chemistry Past Questions and Answers

Waec Chemistry Questions

Question 121:

In the reaction represented by the equation; 2FeCI₃ + SO₂ + 2H₂O â†’ 2FeCL₂ + H₂SO₄ + 2HCI the oxidation number of sulphur changes from

SchoolNGR Classroom

A +2 to + 6
B + 4 to + 6
C 0 to + 6
D - 2 to + 4
E +2 to + 4

View Answer & Explanation

Question 122:

Which of the following equations represents the reaction leading to the removal of permanent hardness of water?

SchoolNGR Classroom

A Ca(HCO ₃)₂ â†’ CaCO₃ + H₂O + CO₂
B MgSO₄ + Na ₂CO₃ + Na ₂SO
C Ca(OH) ₂ + 2HCI â†’ CaCI ₂ + 2H ₂O
D Ca(HCO₃)₂ + Ca(OH)₃ â†’ 2CaCO₃ + 2H₂O
E MgSO₄ + BaCI₂ â†’ MgCI₂ + BaSO₄

View Answer & Explanation

Question 123:

The following alloys contain copper except

SchoolNGR Classroom

A Magnalium
B Duralumn
C Bronze
D Brass
E Type metal

View Answer & Explanation

Question 124:

How many mole of AgNO ₃ are there in 500cm³ of 0.01MAgNO₃ solution?

SchoolNGR Classroom

A 0.005 mole
B 0.05 mole
C 0.5 mole
D 5 moles
E 1 mole

View Answer & Explanation

Question 125:

Which of the following statements explains why tetraoxosulphate (IV) acid is reqarded as a strong acid?

SchoolNGR Classroom

A Tetraoxosulphate (IV) acid is dibasic
B The acid is concentrated
C The acid is complately ionized in aqueous solution
D Tetraxosulphate (IV) ions are very reactive
E The acid is highly corrosive

View Answer & Explanation

Stay Updated

Follow us on:

Subjects