Chemical combination - Jamb Chemistry Past Questions and Answers

Question 111:

• JAMB 2006

2C₂H_2(g) + 5O_2(g) → 4CO_2(g) + 2H₂O_(g)
In the reaction above, the mass of carbon(IV)oxide produced on burning 78 g of ethyne is
[C =12, O = 16, H = 1]

A. 264 g
B. 39 g
C. 352 g
D. 156 g

Question 112:

• JAMB 2006

Na2CO3(g) + 2HCl(aq) → 2NaCl(aq) + H2O(l) + CO2(g)
How many moles of sodium trioxocarbonate (IV) are there in a 25 cm3 solution which required 10cm3 of 0.05 mol dm-3 hydrochloric acid solution to neutralize it?

A. 1.000 mole
B. 0.100 mole
C. 0.010 mole`
D. 0.111 mole

Question 113:

• JAMB 2007

Calculate the number of moles of HCl present in 20cm³ of a 0.75M solution of the acid

A. 0.015 mole
B. 0.038 mole
C. 3.800 moles
D. 1.500 moles

Question 114:

• JAMB 2007

Calculate the mass of chlorine gas which occupies a volume of 1.12dm³ at s.t.p
[Cl = 35.5, molar volume of gas at s.t.p = 22.4 dm³

A. 15.50 g
B. 7.10 g
C. 3.55 g
D. 1.80 g

Question 115:

• JAMB 2007

What is the volume of oxygen required to burn complete 45 cm³ of methane at s.t.p?

A. 135.0 cm³
B. 180.0 cm³
C. 45.0 cm³
D. 90.0 cm³