Chemical combination - Jamb Chemistry Past Questions and Answers

Question 141:

• JAMB 2018

How many atoms are present in 6.0g of magnesium? [Mg = 24, N.A = 6.02 x 10 \(^{23}\)mol]

A. 1.20 x 10\(^{22}\)
B. 2.4 x 10\(^{22}\)
C. 1.51 x 10\(^{22}\)
D. 3.02 x 10\(^{22}\)

Question 142:

• JAMB 2018

A balanced chemical equation obeys the law of

A. Conservation of mass
B. Definite proportions
C. Multiple proportions
D. Conservation of energy

Question 143:

• JAMB 2018

Calculate the percentage composition of oxygen in calcium trioxocarbonate(IV) [Ca=40, C=12, O=16]

A. 16
B. 48
C. 40
D. 12

Question 144:

• JAMB 2018

If the molecular mass of tetraoxosulphate (VI) acid is 98, calculate its vapour density.

A. 196
B. 49
C. 106
D. 82

Question 145:

• JAMB 2019

By what amount must the temperature of 200cm\(^3\) of Nitrogen at 27°C be increased to double the pressure if the final volume is 150cm\(^3\) (Assume ideality)

A. 150°C
B. 177°C
C. 75°C
D. 120°C