Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
Before a reaction could take place, there should be
ionization of reactant particles
breakage of bonds of products
breakage of bonds of reactants
ionization of product particles
Correct answer is C
Activation energy must be achieved before reaction begin. This is because in any chemical reaction, chemical bonds in the reactants are broken, and new bonds in the products are formed
SO\(_{4}\) \(^{2-}\) ions
SO\(_{3}\) \(^{2-}\) ions
NO\(_{3}\)- ions
SO\(_{3}\) \(^{2-}\)- ions
Correct answer is D
Effervescence is the formation of gas bubbles in a liquid by a chemical reaction. An example of effervescence is the release of carbon dioxide which bubbles as a gas from the liquid when limestone chips, which are composed of calcium carbonate, are added to dilute hydrochloric acid.
Increasing the temperature generally
decreases the solubility of a solid in a liquid but increases the solubility of a gas in a liquid.
increases the solubility of a solid in a liquid but decreases the solubility of a gas in a liquid.
increases the solubility of both a solid and a gas in a liquid
decreases the solubility of both a solid and a gas in a liquid
Correct answer is B
-The solubility of gases in liquids decreases with increasing temperature. Conversely, adding heat to the solution provides thermal energy that overcomes the attractive forces between the gas and the solvent molecules, thereby decreasing the solubility of the gas
-The solubility of most solid or liquid solutes increases with increasing temperature
Marble chips and 2.0 mol dm\(^{-3}\) HCl\(_{(aq)}\)
Marble chips and 2.5 mol dm\(^{-3}\) HCl\(_{(aq)}\)
Powdered marble and 2.5 mol dm\(^{-3}\) HCl\(_{(aq)}\)
Powdered marble and 2.0 mol dm\(^{-3}\) HCl\(_{(aq)}\)
Correct answer is C
Powdered marble reacts more rapidly with HCl than the chips of marble because:
Surface area of powdered marble is more that of chips of marble and hence there is more collisions between the molecules of reactants
Number of molecules increases.
Energy of activation decreases
Marble chips will not react with HCl
acidified K\(_{2}\)Cr\(_{2}\)O\(_{7}\) solution colourless
acidified KMnO\(_{4}\) solution colourless
Fe(NO\(_{3}\))\(_{2}\) solution green
Pb(NO\(_{3}\))\(_{2}\) paper black
Correct answer is B
If the potassium manganate(VII) solution is acidified with dilute sulfuric acid, the purple solution becomes colourless.