Questions

Hydrogen is the common element to all Acids. But every element which contains Hydrogen is not an Acid. Most of the acids also contain Oxygen.

Author of the book A journey  is Tony Blair

RST0, RST1, RST2, RST3, RST4, RST5, RST6, RST7.

Biodegradable substances can be broken down into simpler, harmless substances in nature with due course of time by the biological process such as action of microbes. They can be recycled as a part of food chain.

Here, Leather bags are biodegradable.

Normality is a way of expressing concentration of a solution and can be calculated by the formula-

Normality (N) = No. of gram equivalent of solute/ volume of solution (in litre)

Gram equivalent weight of H2 SO4 = Molecular weight/ No. of Hydrogen atom = 98/2 = 49 gm

No. of gram equivalent in 49 gm of H2 SO4 = 1

So, Normality in 1 litre of solution = 1/1 = 1 N

A 40% solution of Formaldehyde known as Formalin is used in the preservation of biological specimens because of its hardening action on proteins.