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Chemistry Past Questions and Answers

Waec Chemistry Questions

Question 1506:

In which of the following compounds is the oxidation number of nitrogen equal to + 3?

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A NO ₂
B N ₂O
C NO
D HNO₂
E HNO₃

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Question 1507:

Which of the following statements is not correct about electrolysis?

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A Reduction occurs at the anode
B Anions migrate to the anode
C Positive ions migrate to the cathode
D Concentration affects the discharge of ions
E Electrolytes conduct electric current

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Question 1508:

Which of the following is not correct about a catalyst? It

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A Remains unchanged chemically at the end of a reaction
B Helps to establish equilibrium faster reversible reaction
C Can start a chemical rection which will normally not take place
D Is usually specific in its action
E Alters the rate of chemical reaction

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Question 1509:

The rate of production of hydrogen gas from the reaction between zinc granules and hydrochloric acid can be increased by

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A Cooling the reaction mixture
B Using zinc powder instead of zinc granules
C Using zinc rod instead of zinc granules
D Carrying out the reaction at a higher pressure
E Carrying out the reaction in a closed vessel

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Question 1510:

What does X represent in the following equation? H _2(g) + 1/2O_2(g) â†’ H₂O _(l); âˆ†H = xKJ.

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A Bond energy
B Activation energy
C Ionization energy
D Enthalpy of neutralization
E Enthalpy of formation

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