Jamb Chemistry 2019 Past Questions and Answers

Question 91:

• JAMB 2019

Which of the following statements about catalyst is false?

A. Biological catalysts are called enzymes
B. Catalyst do not appear in the balanced equation
C. Catalyst reduce the activation energy for a reaction
D. Catalysts do not alter the mechanism of the reaction and never appear in the rate low

Question 92:

• JAMB 2019

Which of the following does not support the fact that air is a mixture?

A. The constituents of air are in a fixed proportion by mass
B. It cannot be represented with a chemical formula
C. The constituents of air can be separated by physical by physical means
D. None of the above

Question 93:

• JAMB 2019

What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)?

A. Fractional crystallization
B. Fractional distillation
C. Filtration
D. Evaporation

Question 94:

• JAMB 2019

At 27°C, 58.5g of sodium chloride is present in 250cm\(^3\) of a solution. The solubility of sodium chloride at this temperature is?
(molar mass of sodium chloride = 111.0gmol\(^{-1}\))

A. 2.0 moldm\(^{-3}\)
B. 0.25 moldm\(^{-3}\)
C. 1.0 moldm\(^{-3}\)
D. 0.5 moldm\(^{-3}\)

Question 95:

• JAMB 2019

Which of the following properties increases from left to right along the period but decreases down the group in the Periodic Table?
i. Atomic Number ii. Ionization energy iii. Metallic character iv. Electron affinity

A. Ii and iii only
B. Ii and iv only
C. Iii and iv only
D. I and ii only