One Word Answer

Name a positive non-metallic radical which is basic in nature.

Answer

Ammonium / NH₄⁺

Reason — Ammonium / NH₄⁺ is a weak base containing a non-metallic nitrogen radical.

How many electrons are present in one molecule of CH₄?

Answer

10 electrons

Reason — carbon - 6 electrons, Hydrogen - 1 electron
There are four hydrogen atoms, so 4 electrons.

∴ Total number of electrons = 6 + 4 = 10 electrons.

Identify the longest carbon chain and mention the number of carbons present in it.

Answer

6

Reason — The below figure shows the longest carbon chain numbered:

Gas M occupies a volume of 1000 c.c and contains X molecules. How many molecules will be present in gas N occupying a volume of 250 c.c?

Answer

$\dfrac{\text X}{4}$

Reason — Let molecules in gas N be Y.

$\dfrac{\text{Molecules in gas N}}{\text{Molecules in gas M}} = \dfrac{\text{Volume of gas N}}{\text{Volume of gas M}} \\[1em] \dfrac{\text{Y}}{\text{X}} = \dfrac{250}{1000} \\[1em] \text{Y} = \dfrac{250}{1000} \times \text{X} \\[1em] \text{Y} = \dfrac{\text{X}}{4}$

Hence, gas N contains $\dfrac{\text X}{4}$ molecules.

Element X belongs to period 2 and group 1 of the periodic table. State the formula of the chloride of the element X.

Answer

XCl

Reason — X is group 1 metal, it loses one electron to attain stability. Chlorine forms a Cl^- ion. Both the ions combine together to form XCl.

Anurag added dilute H₂SO₄ to a given sample X and heated the mixture. He observed that a gas was liberated which had a foul smell of rotten eggs and it turned moist lead acetate paper silvery black. Name the gas evolved in the above case.

Answer

Hydrogen sulphide gas

Reason — When dilute H₂SO₄ is added to a given sample X and heated, it produces H₂S gas, which had a foul smell of rotten eggs.

Metal sulphide + H₂SO₄ (dil.) ⟶ Metal salt + H₂S

H₂S turns moist lead acetate paper black.

H₂S + Pb(CH₃COO)₂ ⟶ PbS(Black) + 2CH₃COOH

Name the alkyl component of acetic acid.

Answer

-CH₃ (methyl)

Reason — Acetic acid consists of a methyl group -CH₃ and a carboxylic acid group -COOH. So, in acetic acid, the alkyl part is methyl group -CH₃.

28g of nitrogen and 44g of carbon dioxide at the same conditions of temperature and pressure occupy the same amount of space. What term describes such space occupied by any gas?

Answer

Molar volume

Reason — When 28 g of nitrogen (N₂) and 44 g of carbon dioxide (CO₂) occupy the same volume, they are both 1 mole each, since:

Molar mass of N₂ = 28 g/mol

Molar mass of CO₂ = 44 g/mol

Hence, the space occupied is called the molar volume of a gas.

When copper reacts with a hot dilute solution, reddish-brown fumes are observed. Another compound, P, having the same anion that is present in the hot solution on heating, melts into a colourless liquid, releasing only oxygen gas without any coloured fumes. Identify P.

Answer

Sodium nitrate / Potassium nitrate

Reason — When copper reacts with a hot dilute solution, reddish-brown fumes of NO₂ are observed.

Cu + 4HNO₃ [dil.] ⟶ Cu(NO₃)₂ + 2H₂O + 2NO₂

Another compound, P, either Sodium nitrate or Potassium nitrate having the same anion NO₃^-, that is present in the hot solution, on heating, melts into a colourless liquid, releasing only oxygen gas without any coloured fumes.

$2\text{NaNO}_3 \xrightarrow{\Delta} \underset{\text{slightly deliquescent}}{2\text{NaNO}_2} + \text{O}_2$ ↑

$2\text{KNO}_3 \xrightarrow{\Delta} \underset{\text{colourless crystalline}}{2\text{KNO}_2} + \text{O}_2$ ↑

Calcite (CaCO₃), a sedimentary rock, is found most abundantly in many geological environments. It has a perfect cleavage in 3 directions, which makes it the most difficult rock to cut, and moreover, the labour of cutting calcite is also very high. What term related to metallurgy will suitably describe Calcite in the context of extracting calcium from calcite?

Answer

Mineral

Reason — Calcite (CaCO₃) is a naturally occurring carbonate mineral. It serves as a source of calcium