List of top Chemistry Questions on Acids, Bases And Salts asked in ICSE Class X board

Given below are a few elements: Li, K, Cs, F.
Identify the element which:
(a) has the least atomic radius.
(b) has two valence electrons.
(c) is the most electropositive.
5.6 litres of gas Z weighs 32 g at STP. What is the molecular weight and vapour density of Z?
Equal volumes of ammonia gas and chlorine gas are kept in two different containers under the same conditions of temperature and pressure. Find the number of molecules contained in chlorine gas when the mass of ammonia is 34 g. (Atomic weight: Cl = 35.5, H = 1, N = 14)
Assertion (A): Dilute Sulphuric acid is a stronger electrolyte than concentrated Sulphuric acid.
Reason (R): Dilute Sulphuric acid has a higher concentration of mobile ions than concentrated Sulphuric acid.