2020 - JAMB Chemistry Past Questions and Answers - page 1

Based on Hund's rule, there are 3 unpaired electrons in P.

The Fractional Distillation of Liquid Air

An air separation unit is often called an oxygen or nitrogen generator since its purpose is to extract one or both of these elements from the air. In the distillation process, the air is first passed through a filter that absorbs all the water vapour.

An air separation plant separates atmospheric air into its primary components, typically nitrogen and oxygen, and sometimes also argon and other rare inert gases. The most common method for air separation is fractional distillation.

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Duralumin is an alloy made up of 90% aluminium, 4% copper, 0.51% magnesium, and less than 1% manganese.

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A polysaccharide is a large molecule made of many smaller monosaccharides. Monosaccharides are simple sugars, like glucose. Special enzymes bind these small monomers together creating large sugar polymers, or polysaccharides. A polysaccharide is also called a glycan.

Via biologydictionary.net

Here's how to solve this problem:

1. Calculate the molar mass of CH₄:

   • C = 12 g/mol
   • H = 1 g/mol, and there are 4 H atoms, so 4 * 1 = 4 g/mol
   • Molar mass of CH₄ = 12 + 4 = 16 g/mol

2. Determine the moles of CH₄:

   • Given: 8 g of CH₄
   • Moles = mass / molar mass = 8 g / 16 g/mol = 0.5 mol

3. Use the given information to find the volume of 1 mole of a gas at STP: *

The treatment: Flushed Sulfuric acid with a mild, soapy solution if the burns are not severe.

Note: Sulfuric acid feels hot when water is added to the acid, but it is better to flush the area and not leave the acid on the skin.

Warning: Don't try to neutralize the burn with acid or alkali. This could cause a chemical reaction that worsens the burn!

Charles' law states that the volume occupied by a fixed amount of gas is directly proportional to its absolute temperature, if the pressure remains constant.

The element with atomic number 17 is Chlorine which has a valency of -1.

Hence, it needs to receive an electron or lose seven electrons to obey the octet rule which refers to the tendency of atoms to prefer to have eight electrons in the valence shell. When atoms have fewer than eight electrons, they tend to react and form more stable compounds

Destructive distillation is a chemical process in which decomposition of unprocessed material is achieved by heating it to a high temperature; the term generally applies to the processing of organic material in the absence of air or in the presence of limited amounts of oxygen or other reagents, catalysts, or solvents, such as steam or phenols.

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Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na⁺ and hydroxide anions OH⁻ . Wikipedia