MHT CET 2017 :: Chemistry :: General questions

• Chemistry - General questions

Which among the following equations represents in the reduction reaction taking place in lead accumulator at the positive electrode, while it is being used as a source of electrical energy?

Answer:

Explanation:

 The reaction  involved for lead accumulator during discharging i.e, when cell is in the use are

At anode:  $Pb(s)+HSO_{4}^{-}(aq)\rightarrow PbSO_{4}(s)+H^{+}+2e^{-}$

 At cathode:  $PbO_{2}(s)+3H^{+}(aq)+HSO_{4}^{-}(aq)+2e^{-}\rightarrow PbSO_{4}(s)+2H_{2}O(l)$

 Overall reaction :    $ Pb(s)+PbO_{2}(s)+2H^{+}+2HSO_{4}^{-}(aq)\rightarrow 2PbSO_{4}(s)+2H_{2}O(l)$

A  molecule of stachyose contains how many carbon atoms?

Answer:

Explanation:

Depending upon the number of monosaccharide molecules condensed to form oligosaccharides such as disaccharides (e.g. sucrose), trisaccharides (e.g., raffinose), tetrasaccharides (e.g, stachyose) etc.

Stachyose contains 24 carbon atoms in its structure

 The amino acid, which is basic in nature is 

Answer:

Explanation:

The amino acids , which contains more number of amino (-NH₂) groups than carboxyl (-COOH)  groups are called basic amino acids

Which of the following co-ordinate complexes is an exception to EAN rule?

(Given atomic number Pt=78, Fe=26, Zn=30, Cu=29)

Answer:

Explanation:

Effective Atomic Number (EAN) can be calculated by the following relation.

EAN= Z(atomic number of the metal) -number of electrons  lost in the ion formation + number of electrons  gained from the donor  atoms of the ligands.

$[Cu(NH_3)_4]^{2+}$ is an exception of EAN rule.

What is the actual volume occupied by water molecules present in 20 cm³ of water ?

Answer:

Explanation:

Half of the volume occupied in water is empty or unoccupied. Therefore, 10 cm³ of the actual volume is occupied by water molecules present in 20 cm³ of water

• Chemistry - General questions