Chemistry (Part-IX)

1. Nitrogen fixation is a process of— [S.S.C. Online Graduate Level (T-I) 11.09.2016]

(a) Assimilation of nitrate
(b) Utilisation of nitrogen gas
(c) Conversion of organic nitrogen to proteins
(d) Conversion of molecular nitrogen to ammonia

Correct Answer: (c) Conversion of organic nitrogen to proteins

Solution:The fixation of atmospheric nitrogen by microscopic animals is a step-by-step process in which nitrogen (N) is first converted into ammonia and nitrate (NO) is formed, which, upon reaching plants, is finally converted into protein.

2. The chemical formula of Ammonia is _______ . [S.S.C. Online CHSL (T-I) 29.01.2017]

(a) NH
(b) NH₁
(c) NH₂
(d) NH₃

Correct Answer: (d) NH₃

Solution:The chemical formula of ammonia is NH₃, it is composed of one nitrogen atom and three hydrogen atoms. Ammonia is a lighter gas than air and is soluble in water. An aqueous solution of ammonia (NH₃) is basic because ammonia reacts with water to form NH₄OH (ammonium hydroxide), which is a weak base.

3. Chemical formula of Ammonia is ________ . [S.S.C. Online CHSL (T-I) 31.01.2017]

(a) PH₃
(b) NO₂
(c) AlN
(d) NH₃

Correct Answer: (d) NH₃

4. The chemical formula of Ammonium Dichromate is ________ . [S.S.C. Online CHSL (T-I) 23.01.2017]

(a) (NH₄)₂Cr₂O₇
(b) (NH₄)CrO₃
(c) (NH₄)Cr₂O₃
(d) (NH₄)₂Cr₂O₃

Correct Answer: (a) (NH₄)₂Cr₂O₇

Solution:The chemical formula of ammonium dichromate is (NH₄)₂Cr₂O₇.

5. Which of the following is the chemical symbol of Curium? [S.S.C. Online MTS (T-I) 12.10.2021]

(a) Ci
(b) Cm
(c) Cr
(d) Cu

Correct Answer: (b) Cm

Solution:Curium (Cm) is a transuranic radioactive chemical element. Its symbol is Cm and its atomic number is 96. This element of the actinide series was named after the eminent scientists Marie Curie and Pierre Curie. Both of them are famous for their research on radioactivity.

6. How many oxygen atoms are present in a molecule of potassium permanganate? [S.S.C. Online CGL (T-I) 23.08.2021]

(a) One
(b) Two
(c) Four
(d) Three

Correct Answer: (c) Four

Solution:The molecular formula of potassium permanganate is KMnO₄. Therefore, it has four oxygen atoms in one molecule.

7. What is the chemical symbol of magnesium? [S.S.C. Online CGL (T-I) 23.08.2021]

(a) Ma
(b) Mg
(c) Ms
(d) Mn

Correct Answer: (b) Mg

Solution:Magnesium (Mg) is a chemical element with the symbol Mg and its atomic number is 12. It is an element in Group II of the periodic table, which is lustrous grey metal.

8. The formula for potassium permanganate is ______ . [S.S.C. Online MTS (T-I) 10.10.2017]

(a) KMnO₄
(b) KMn₂O₄
(c) K₂Mn₂O₄
(d) K₂Mn₂O₂

Correct Answer: (a) KMnO₄

Solution:The chemical formula of potassium permanganate is KMnO₄, It is a strong oxidizing agent. It is used as a bactericide and for washing wounds etc.

9. The symbol of Tin is ______ . [S.S.C. Online MTS (T-I) 12.10.2017]

(a) Sn
(b) Cl
(c) Tl
(d) Tn

Correct Answer: (a) Sn

Solution:The symbol for tin is Sn. It is a member of the carbon family of group 14 in the periodic table. Tin is a silvery-white soft metal with the atomic number 50.

10. Which of the following intermolecular is also called as London force? [S.S.C. Online CPO SL (T-I) 11.11.2022]

(a) Dispersion Forces
(b) Dipole-Induced Dipole Forces
(c) Dipole-Dipole Forces
(d) Hydrogen band forces

Correct Answer: (a) Dispersion Forces

Solution:London forces are also known as Dispersion force. This is the weakest intermolecular force. This is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.