JAMB Chemistry Past Questions & Answers - Page 430

2,146.

The solution with the lowest pH value is

A.

5 ml of (m/10) HCL

B.

10 ml of (m/10) HCL

C.

15 ml of (m/5) HCL

D.

20 ml of (m/8) HCL

Correct answer is A

No explanation has been provided for this answer.

2,147.

What is observed when aqueous solutions of each of tetraoxosulphate (VI) acid, potassium trioxoiodate (V) and potassium iodide are mixed together?

A.

A white precipitate is formed

B.

A green precipitate is formed

C.

The mixture remains colourless

D.

The mixture turns reddish brown

Correct answer is D

No explanation has been provided for this answer.

2,148.

The set of pollutants that is most likely to be produced when petrol is accidentally spilled on plastic materials and ignited is

A.

CO, CO2 and SO2

B.

CO, HCL and SO2

C.

CO, CO2 and HCL

D.

SO2, CO2 and HCL

Correct answer is B

No explanation has been provided for this answer.

2,149.

The correct order of increasing oxidation number of the transition metal ions for the compounds K2Cr2O7, V2O5 and KMnO4 is

A.

V2O5 < K2Cr2O7 < KMnO4

B.

K2Cr2O7 < KMnO4 < V2O5

C.

KMnO4 < K2Cr2O7 < V2O5

D.

KMnO4 < V2O5 < K2Cr2O7

Correct answer is A

No explanation has been provided for this answer.

2,150.

0.25 mole of hydrogen chloride was dissolved in distilled water and the volume made up of 0.50 dm3. If 15.0 cm3 of the solution requires 12.50 cm3 of aqueous sodium trioxocarbonate (IV) for neutralization, calculate the concentration of the alkaline solution

A.

0.30 mol dm3

B.

0.40 mol dm3

C.

0.50 mol dm3

D.

0.60 mol dm3

Correct answer is A

M1 V1 = M2 V2
∴ Mn Vn represent volume and molar concentration of HCL also MyVy represent volume and molar concentration of Na2CO3
MnVn = MyVy
0.25 * 15 = 12.50 * My
My = (0.25 * 15)/12.50
My = 0.3m/dm3