A substance X, which is an oxide of a group 2 element, is used intensively in the cement industry. This element is presented in bones also. On treatment with water it forms a solution which turns red litmus blue. Identify X and also write the chemical reactions involved.

An element A reacts with water to form a compound B which is used in white washing. The compound B on heating forms an oxide C which on treatment with watr gives back B. identify A, B and C and give the reacitons involved.

When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (Molecular mass=40) and liberates a gas Z which easily catches fire. Identify X,Y and Z and also write the reaction involved.

A metal carbonate X, and a metal bicarbonate Y on reacting with an acid gives a gas which turns lime water milky. Write the chemical equatins for the reaction of X and Y with the acid.

A sulphate salt of the group 2 element of the periodic table is a white, soft substance, which can be molded into different shapes by making its dough. When this compound is left in open for some time, it becomes a solid mass and cannot be used for molding purposes. Identify the sulphate salt and why does the show such a behaviour? give one reaciton involved.

A water soluble compound 'X' of sodium on reacting with dil. H_2SO_4 released a colourless gas accompanied by brisk effervescence. When the gas was passed through water, the solution obtained turned blue litmus solution red. On bubling the gas through lime water, it initially became milky and the milkness disappeared when the gas was passed in excess. Identify the substance 'X' and write the chemical equation for the reactions involved.

In one of the industrial processes used for manufacture of sodium hydroxide, a gas ‘X’ is formed as a by-product. The gas ‘X’ reacts with lime water to give a compound ‘Y’ which is used as a bleaching agent in the chemical industry. Identify ‘X’ and ‘Y’ giving the chemical equations of the reactions involved.

An element x reacts with oxide to from oxide, X_2O which dissolves in water and turns red litmus solution blue, give the nature of oxide and indicate X is metal or non-metal.

An element A burns with golden flame in air. It reacts with another element B, atomic number 17 to give a product C. An aqueous a solution of product C on electrolysis gives a compound D and liberates hydrogen. Identify A,B,C or D. Also write down the equations for the reaction involved.