“Sodium cannot be kept open in atmospheric air,and cannot be stored in water. So it is stored in kerosene.” Give explanation for the above statement with its chemical equation.

Give reasons (vi) Aluminium utensils cannot be kept in water overnight

A freshly cut piece of sodium when exposed to air for some time looses its lustre in the freshly cut portion. a) What may be the reason for this?. b) Write any two chemical equations to substantiate your answer.

When bromoethane is reacted with sodium in the presence of ether an alkane is formed.Give the chemical equation for the above reaction.

Some substances when dissolved in water cause hardness of water. Sodium chloride, Calcium bicarbonate, Calcium carbonate, Calcium sulphate, Magnesium sulphate, Calcium chloride, Magnesium carbonate. The hardness due to which of the above salts cannot be removed by boiling?

Which of the following statements are true? i) Rhamnose and deoxyribose are carbohydrates by their chemical behavior but cannot represented as hydrates of carbon ii) Formaldehyde and acetic acid do not behave like carbohydrate but can be represented by the general formula of carbohydrates, C_x(H_2O)_y iii) Raffinose on hydrolysis gives glucose and galactose only iv) Polysaccharides are also called non-sugars v) In disaccharides, if reducing groups of monosaccharides are bonded, they are non reducing in nature vi) Sorbose is an example of aldose

Classify the following into physical changes and chemical changes. 1. Melting of ice 2. Heating magnesium in water 3. Silver bromide kept exposed to sunlight 4. Change happening to soda water on opening its bottle.