general chemistry help high school

Molecular hydrides are soft. They are generally, volatile in nature and have low melting and boiling points. They have low electrical conductivity. The electronegativity difference between hydrogen and the atom bonded to it, determines the properties of covalent hydrides. When ..

Electron affinity is the amount of energy released, when an isolated gaseous atom accepts an electron to form a negative ion. The other atom participating in the formation of an ionic compound must form an anion by gaining an electron (s). Higher electron affinity favours the formation of an anion..

In this process, coal is heated in the absence of air to about 1273 - 1473 K. The major products of high temperature pyrolysis are, Coal..

They are generally solids with characteristics such as hardness, malleability, ductility high tensile strength, lustre and ability to conduct heat and electricity. For example: Copper, iron, zinc e..

Ionic compounds are generally soluble in water and other polar solvents having high dielectric constants. This is due to larger electrostatic interactions between polar solvents and ions. However ionic compounds are insoluble in non-polar solvent..

Boron is unreactive to most chemical reagents at ordinary temperature. It reacts only with strong oxidizing agents such as fluorine and concentrated nitric acid at room temperature. However, it combines with metals at very high temperatures to form borides, which are generally ..

Silicones are polymeric compounds containing Si-O-Si linkages. These have the general formula (R 2 SiO) n . These may be linear cyclic or cross-linked. These have very high thermal stability and are called high temperature polymers (R may be alkyl or phenyl group..

This method is based on the relative solubility of the compounds in organic solvents versus aqueous medium. The organic liquid in which the compound is more soluble is generally called as 'solvent'. The solvent chosen should satisfy the following conditions: The solvent should be immis..

As a lubricant at higher temperatures. As a refractory material of making crucibles and electrodes for high temperature work. In electrotyping and in the manufacture of gramophone records: Graphite is used for making the non-conducting (generally wax) surface, so that el..

The catalysts used in this process are platinum or vanadium pentoxide (V 2 O 5 ) that are heated to a high temperature. The optimum temperature required is 450 - 500 o C. Remember:- Low temperature favours the oxidation of sulphur dioxide. If the temperature is too low, the rate o..