The function of ''Sodium pump'' is a biological process operating in each and every cell of all animals. Which of the following biologically important ions is also a constituent of this pump?
A
K+
B
Fe2+
C
Ca2+
D
Mg2+
Explanation
K+ ion is a constituent of sodium pump.
2
AIPMT 2015 Cancelled Paper
MCQ (Single Correct Answer)
Solubility of the alkaline earth metal sulphates in water decreases in the sequence
A
Sr > Ca > Mg > Ba
B
Ba > Mg > Sr > Ca
C
Mg > Ca > Sr > Ba
D
Ca > Sr > Ba > Mg
Explanation
Solubility of alkaline earth metal sulphates
decreases down the group because hydration
energy decreases.
3
AIPMT 2015
MCQ (Single Correct Answer)
On heating which of the following releases CO2 most easily?
A
Na2CO3
B
MgCO3
C
CaCO3
D
K2CO3
Explanation
Carbonates becomes more thermally stable
down the group, Also,
the alkali metal carbonate are more stable than
alkaline earth metal carbonates. Therefore MgCO3 will leave
CO2 easily.
MgCO3
$$\buildrel \Delta \over
\longrightarrow $$ MgO + CO2
4
AIPMT 2015
MCQ (Single Correct Answer)
20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample?
(At. wt. of Mg = 24)
A
96
B
60
C
84
D
75
Explanation
MgCO3
$$\buildrel \Delta \over
\longrightarrow $$ MgO + CO2
84 g of MgCO3
$$ \equiv $$ 40 g of MgO
$$ \therefore $$ 20 g of MgCO3 = $${{40} \over {84}} \times 20$$ = 9.52 g of MgO