chemistry for grade 7\

Reaction takes place in acidic medium, so add H+ ions to the side deficient in H+ and balance H and O atoms..

Calculate the vapor density and molecular weight of CO 2 gas occupying 200 mL and weighing 0.40 g at ST..

How many grams of pure sulphuric acid is present in 0.05 mole of it? (H=1, S=32, O=1..

The molecular mass (or molar mass) is obtained either from the experimental data or from the vapor density of the compound by using the relationship, Molecular mass = 2 x Vapor dens..

Catenation is the tendency of an atom to form bonds with identical atoms. In this group only sulphur has a strong tendency for catenation. Oxygen also shows this tendency to a limited extent. Thus the polyoxides and polysulphides of the following types are known: H 2 O 2 , H - O - O - H Polyoxides..

All the halogens are colored. The color of different halogens are given below: Halogen Fluorine Chlorine Bromine Iodine Colour Light yellow Greenish yellow Reddish brown Dark violet Explanation: The color of halogens is due to the fact that their molecules absorb radiations from..

When carbon dioxide is passed over red-hot carbon in the form of coke charcoal, etc., the carbon dioxide loses one of its two atoms of oxygen. As a result, carbon dioxide gets reduced and becomes carbon monoxide. At the same time the hot carbon also gets converted to carbon monoxide (Fig.11.12). ..

A mixture of 97% oxygen and 3% carbon dioxide, called carbogen is used to revive persons affected by carbon monoxide poisoning, pneumonia, asphyxiation etc. b) Over production of hydrochloric acid in the gastric juice causes acidity. Health salts mostly contain sodium hydrogen carbonate, which rea..

Solute/Solubility 0 o C 20 o C 60 o C 100 o C Calcium hydroxide 1.19 0.17 0.12 0.08 Calcium sulphate 0.18 0.19 0.20 0.16 Cerium sulphate 17.35 9.16 3.73 - If the solute and solvent are both soluble liquids, like alcohol and water, there is no limit to solubility i..

An example of sharing of three pairs of electrons (Triple bond) Two atoms of nitrogen share three pairs of electrons to form one molecule of nitrogen (Fig. 3.6). Note : ..