Chemistry JAMB, WAEC, NECO AND NABTEB Official Past Questions

Addition of dilute hydrochloride acid to an aqueous solution of a crystalline salt yield a yellow precipitate and a gas which turned dichromate paper green. The crystalline salt was probably?

When marble is heated to about 1473 K, another white solid is obtained which reacts vigorously with water to give an alkaline solution. The solution contains?

The atomic number of an element whose cation, X2+, has the ground state electronic configuration 1s22s22p63s22p6 is?

Which of the following compounds is NOT the correct product formed when the parent metals is heated in air?

A colourless organic compound X was burnt in excess air to give two colourless and odourless gases, Y and Z, as products. X does not decolorize blue bromine vapour, Y turns lime milky while Z gives a blue colour with copper (ll) tetraoxosulphate (IV).
Y and Z are respectively?

A colourless organic compound X was burnt in excess air to give two colourless and odourless gases, Y and Z, as products. X does not decolorize blue bromine vapour, Y turns lime milky while Z gives a blue colour with copper (ll) tetraoxosulphate (IV).
Compound X is?

Which of the following substances is the most abundant in the universe?

Solid sodium hydroxide on exposure to air absorbs a gas and ultimately gives another alkaline substance with the molecular formula?

An organic compound decolourized acidified KMnO₄ solution but failed to react with ammoniacal silver nitrate solution. The organic compound is likely to be?

Tetraoxosulphate (IV) ions are finally tested using?

The energy change (ΔH) for the reaction CO(g) + (1)/(2)O_2(g) → is?

(ΔHi(CO) = -110.4 kJ mol^–) (ΔHi(CO₂) = -393 kJ mol^–)

When pollen grains are suspended in water and viewed through a microscope, they appear to be in a state of constant but erratic motion. This is due to?

A man suspected of being drunk is made to pass his breath into acidified potassium dichlormate solution. If his breath carries a significant level of ethanol, the final colour of the solution is?

Which of the following is used in the manufacture of bleaching powder?

Complete hydrogenation of ethyne yields?

In the reaction H_2(g)O \(\to\) H_2(g) + 1/2O_2(g)

ΔH = -2436000 KJ, which of the following has no effect on the equilibrium position?

Which of the following metals will displace iron from a solution of iron(ll)tetraoxosulphate(lV)?

2MnO^–₄ + 10Cl^– + 16H⁺ → 2Mn²⁺ + 5Cl₂ + 8H₂O. Which of the substances serves as an oxidizing agent?

A certain industrial process is represented by the chemical equation 2A_(g) + B_(g) \(\to\) C_(g) + 3D_(g) \(\Delta\)H = X kJmol^-1. Which of the following conditions will favour the yield of the products?

A correct electrochemical series can be obtained from K, Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging?

If the ONLY pollutants found in the atmosphere over a city are oxides of nitrogen, suspended lead compounds. carbon monoxide and high levels of methane, the probable source(s) of the pollution must be?