List of top Chemistry Questions on Chemical Reactions asked in ICSE Class X board

Name the following:
(a) The most electronegative element of Period 2
(b) The largest atom of Period 3
Complete the following sentences by choosing the correct option from the brackets:
(a) The oxide that dissolves in caustic potash (KOH) is [ZnO / CuO]
(b) The reaction that takes place at the anode during the electrolysis of molten lead bromide is [2Br(^-) () Br(_2) + 2e(^-) / 2Br(^-) + 2e(^-) () 2Br(^-)]
(c) The volume occupied by 8 grams of oxygen gas at STP is ______ litres. [15 / 8.96] [Atomic weight of O = 16]
(d) ______ does not give hydrogen gas when it reacts with cold and very dilute nitric acid. [Cu / Mn]
(e) ______ is a polar covalent compound [HCl / CCl(_4)]

Match Column A with Column B: 

 

Identify the following terms / compounds:
(a) A compound which reacts with water to give acetylene gas.
(b) The gas evolved when sodium propanoate is heated with soda lime.
(c) A reddish-brown precipitate formed when ferric chloride solution reacts with an alkali.
(d) A pair of electrons present in an atom which is not shared with any other atom during bond formation.
(e) The relative molecular mass of a substance expressed in grams.
The compound that has the highest melting point amongst the following is:

Rita added dilute hydrochloric acid to four metals. She recorded her observations in the table given below. While noting her observations she made some errors. 

 

A non-metal which reacts with concentrated sulphuric acid to form two gases which turn lime water milky is ______.