Neco Chemistry 2009 Past Questions and Answers

Question 21:

• NECO 2009

Which of the following gases is absorbed from the air dun photosynthesis?

A. Carbon (II) oxide
B. Carbon (IV) oxide
C. Nitrogen
D. Noble gases
E. Oxygen

Question 22:

• NECO 2009

X = - log₁₀ H⁺]

What does X stand for in the expression above?

A. Degree of acidity
B. Enthalpy change
C. Equilibrium constant
D. Ionic product of water
E. Solubility product

Question 23:

• NECO 2009

During the extraction of iron in the blast furnance, slag is produced using

A. Carbon
B. Crylite
C. Limestone
D. Oxygen
E. Sulphur

Question 24:

• NECO 2009

Brain tumors can be located by using an isotope of ____________

A. Carbon - 14
B. Iodine 131
C. Technetium 99
D. Uranium235
E. Uranium 238

Question 25:

• NECO 2009

What volume of carbon (IV) oxide in dm ³ is produced at s.t.p. when 2.50g of CaCO₃ reacts with excess acid according to the following equation? CaCO₃(s) + 2HCI(aq) → CaCl₂(aq) + H₂O(1) + CO₂(g)

[CaCO₂ 100; molar volume of a gas at s.t.p. = 22.4dm ³]

A. 0.28
B. 0.56
C. 2.24
D. 5.6
E. 11.2