Chemistry Questions

Passivity of iron is due to formation of an extremely thin and impervious film of ferrosoferric oxide Fe3O4on the surface of iron. Chromic acid, being a powerful oxidising agent (like nitric acid ) renders iron passive. 

Covalent type of bonding joins The two hydrogen atoms are joned by Covalent type of bonding.

In this type of bonding, electrons are shared between the atoms in order to fill there valence shells. Thus sharing of electrons take place in between the hydrogen atoms.

An Element is a pure substance of one type of atom. In chemistry, any material such as carbon, hydrogen, iron, or oxygen that cannot be broken down into more fundamental substances is nothing but an element.

Atomic weight=number of neutrons+number of protons

In the form of vinegar, acetic acid is known from very early times. It is got by oxidation of fermented liquors (10-15%, alcohol) by air under the influence of a bacteria called 'mycoderma acetic'

1 mole of CO2 contain 12gms of carbon and 44 gms of CO2

therefore  24 gms of carbon is present in 88 gms of CO2 or 2 moles of CO2

Moles of solute present in 1 litre or 1000ml of solution is called molarity

The nucleus of hydrogen consists of only a single proton.

Its parts are a single negatively-charged electron that circles a single positively-charged nucleus of the hydrogen atom.

The electron is bound to the nucleus by the Coulomb force.