1
MCQ (Single Correct Answer)

AIPMT 2015 Cancelled Paper

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
MCQ (Single Correct Answer)

AIPMT 2015

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

But Actual yield = 8 g of MgO

$$ \therefore $$ % purity = $${8 \over {9.52}} \times 100$$ = 84%
3
MCQ (Single Correct Answer)

AIPMT 2015

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
MCQ (Single Correct Answer)

NEET 2013 (Karnataka)

In Castner-Kellner cell for production of sodium hydroxide
A
brine is electrolyzed using graphite electrodes
B
molten sodium chloride is electrolysed
C
sodium amalgam is formed at mercury cathode
D
brine is electrolyzed with Pt electrodes

Explanation

In Castner-Kellner cell, sodium amalgam is formed at mercury cathode.

EXAM MAP

Joint Entrance Examination

JEE Advanced JEE Main

Medical

NEET

Graduate Aptitude Test in Engineering

GATE CE GATE ECE GATE ME GATE IN GATE EE GATE CSE GATE PI