List of practice Questions

Which element is not present in Nessler's reagent?
Delicate balance of \(CO_2\) and \(O_2\) is not disturbed by:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Polluted water may have a value of BOD of the order of 17 ppm.

Reason R: BOD is a measure of oxygen required to oxidise both the bio-degradable and non-biodegradable organic material in water.

In the light of the above statements, choose the most appropriate answer from the options given below.

C(s)+O2(g)→CO2(g)+400 kJ
C(s)+\(\frac{1}{2}\) O2(g)→CO(s)+100 kJ
When coal of purity 60% is allowed to burn in presence of insufficient oxygen, 60% of carbon is converted into ‘CO’ and the remaining is converted into ‘CO2’. The heat generated when 0.6 kg of coal is burnt is _______.

Given below are two statements:
Statement I : Chlorine can easily combine with oxygen to form oxides; and the product has a tendency to explode
Statement II : Chemical reactivity of an element can be determined by its reaction with oxygen and halogens
In the light of the above statements, choose the correct answer from the options given below