Organic Chemistry — Chemistry STD 10 — Question

How would you obtain an alkali from a base.

The atomic mass of Chlorine is 35.5. What is its vapour density?

The following table shows the tests a student performed on four different aqueous solutions which are X,Y,Z and W. Based on the observations provided, Identify the cation present

Chemical Test	Observation	Conclusion
To Solution X, ammonium hydroxide is added in minium quantity first and then in excess	A dirty white precipitate is formed which dissolves in excess to form a clear solution	(i)
To Solution Y, ammonium hydroxide is added in minimum quantity first and then in excess	A pale blue precipitate is formed which dissolves in excess to form a clear inky blue solution	(ii)
To solution W, A small quantity of sodium hydroxide solution is added and then in excess	A white precipitate is formed which remains insoluble	(iii)
To a salt Z, calcium hydroxide solution is added and then heated	A pungent smelling gas turning moist red litmus paper blue is obtained	(iv)

Give the principles of:
froth floatation process

State the position of the following in the periodic table:
Aluminium

Name the metal which is a constituent of Blood pigment ?

Write the following properties of ethene:
Solubility

Aluminium is extracted from its chief ore, bauxite. The ore is first purified and then the metal is extracted from it by electrolytic reduction
Write an equation for the reaction which takes place at the anode during the extraction of
aluminium by the electrolytic process ?

Give example of compound whose:
Empirical formula is different from the molecular formula.