Chemistry Past Questions and Answers

The periodic classification of elements is an arrangement of the elements in order of their

In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?

A small quantity of solid ammonium chloride (NH<sub style='font-size: smaller;'>4</sub>Cl) was heated gently in a test tube, the solid gradually disappears to produce two gases. Later, a white cloudy deposit was observed on the cooler part of the test tube. The ammonium chloride is said to have undergone

Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,

An element X forms the following compounds with chlorine; XCl<sub style='font-size: smaller;'>4</sub>, XCl<sub style='font-size: smaller;'>3</sub>, XCl<sub style='font-size: smaller;'>2</sub>. This illustrates the