2020 - JAMB Chemistry Past Questions and Answers - page 4

Tetrachloromethane is an effective solvent within the chemical industry and is used to clean machinery and electrical equipment. That is to say that it functions as a solvent for oils, fats, lacquers, varnishes, rubber waxes, and resins, and as a grain fumigant.

2H\(_2\) + O\(_2\)  ⇒ 2H\(_2\)O

From the equation:

4g of Hydrogen produces 36g of water

8g of Hydrogen will produce 72g of water

Acid hydrolysis refers to a hydrolysis reaction occurring under acidic conditions. Acid hydrolysis of a protein breaks the polymer down into its constituent amino acids.

In organic chemistry, acid hydrolysis is a hydrolysis process in which a protic acid is used to catalyze the cleavage of a chemical bond via a nucleophilic substitution reaction, with the addition of the elements of water. For example, in the conversion of cellulose or starch to glucose. Wikipedia

Alkanals (Aldehydes) have the general formula RCHO while Alkanones or Ketones have the general formula RCOR'.

Where R and R' may be alkyl or aryl groups.

When these cathode rays are deflected onto an electrode of an electrometer, the instrument measured a negative charge. The rays tested also were deflected by the application of an electric field.

Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state

A halide ion is a halogen atom bearing a negative charge. The halide anions are fluoride (F−), chloride (Cl−), bromide (Br−), iodide (I−) and astatide (At−). Such ions are present in all ionic halide salts. Halide minerals contain halides.

More.

Aluminium hydroxide, Al(OH)₃ is used as a mordant in dyeing.

Earth's crust is made up of several elements: oxygen, 46.6% by weight; silicon, 27.7%; aluminum, 8.1%; iron, 5%; calcium, 3.6%; sodium, 2.8%, potassium, 2.6%, and magnesium, 2.1%.

Carbon monoxide, that is Carbon(ii)oxide is prepared from carbon(iv)oxide by passing the latter through red-hot carbon and the unchanged CO\(_2\) is removed when the mixture of the gases through conc NAOH.