If temperature of a gas is kept constant and pressure is doubled, volume becomes: MCQ with Answer and Explanation

Explanation:
A small amount of ethanol (alcohol) is added to chloroform to inhibit its oxidation by air to toxic phosgene (COCl₂) and HCl. Ethanol acts as a negative catalyst (stabilizer) by consuming any formed phosgene. MnO₂, Pt, Fe are positive catalysts. Negative catalysts are also called inhibitors, used to prevent undesirable reactions.

Explanation:
Methane is CH₄, the simplest alkane with one carbon atom bonded to four hydrogen atoms. The series general formula is CₙH₂ₙ₊₂. For n=1, H=4. CH, CH₂, CH₃ are not stable neutral molecules; they are fragments (methyl radical etc.). Methane is a major component of natural gas and biogas.

Explanation:
Periods are horizontal rows (7 periods). Groups are vertical columns (18). Elements in same period have same number of electron shells.