Chemistry - Study Mode

[#401] Nitrogen in water is commonly found in the form of
Correct Answer

(D) Nitrite

Explanation

Solution: Nitrogen enters water in numerous forms, including both inorganic and organic forms. The primary inorganic forms of N are ammonia, ammonium, nitrate, and nitrite. Commonly found is nitrite.

[#402] Aquaregia is a mixture of the following in the ratio 1 : 3 by volume
Correct Answer

(A) Conc. HNO 3 and conc. HCl

Explanation

Solution: Aqua regia or nitro-hydrochloric acid is a highly corrosive mixture of acids which is formed by freshly mixing concentrated Nitric acid (HNO 3 ) and Hydrochloric acid (HCl), optimally in a volume ratio of 1 : 3. It is used in dissolving gold.

[#403] One of the following is used to dissolve noble metals. That is
Correct Answer

(D) Aqua regia

Explanation

Solution: Aqua regia is a mixture of concentrated hydrochloric acid and nitric acid in the ratio of 3:1, and can dissolve noble metals like gold.

[#404] Atomic number is the number equal to
Correct Answer

(A) Protons

Explanation

Solution: Atomic number is the number of protons, and therefore also the total positive charge, in the atomic nucleus.

[#405] Rutherford’s scattering experiment proved the presence of
Correct Answer

(D) Nucleus in atoms

Explanation

Solution: Rutherford's gold foil experiment demonstrated that almost all of the mass of an atom is in a tiny volume in the center of the atom which Rutherford called the nucleus. This positively charged mass was responsible for deflecting alpha particles propelled through the gold foil.