Chemistry - Study Mode

[#846] Equal masses of oxygen, hydrogen and methane are kept under identical conditions. The ratio of the volumes of gases will be
Correct Answer

(C) 1 : 16 : 2

Explanation

Solution: Convert the mass into moles ( use the formula n=m/Mr ) m = mass and Mr = Molecular weights Molecular weights are 32( Oxygen ), 2( Hydrogen ), and 16( Methane ), respectively. Since the masses are equal, you can take the mass as x. So, the number of moles would be: n(O2) = x/32 n(H2) = x/2 n(CH4) = x/16 The ratio of their volumes is (O 2 ) : (H 2 ) : (CH 4 ) = 1 : 16 : 2

[#847] The mass number of an atom is equal to
Correct Answer

(C) the number of nucleons

Explanation

Solution: The mass number of an atom is equal to the number of nucleons.

[#848] The maximum number of covalent formed by nitrogen is
Correct Answer

(D) 4

Explanation

Solution: Covalency of an atom in a covalent compound is the number of covalent bonds formed by an atom. Maximum covalency of Nitrogen is 4 (example - ammonium ions).

[#849] The formula C 6 H 5 -CO-CH 3 represents
Correct Answer

(C) Acetophenone

Explanation

Solution: The formula C 6 H 5 -CO-CH 3 represents Acetophenone.

[#850] The metal that is usually extracted from sea water is
Correct Answer

(D) Mg

Explanation

Solution: In the US, 63% of magnesium production came from seawater and brines during 2015. The metal is extracted from seawater and brines by means of electrolysis, a process that requires the passing of a current through a molten salt.