5. 20
11. 20
2. 24
20. 20
6. 20
Correct answer is B
P4 + 502 → P4O10
for the complete combustion of 124 grammes of phosphorus we need
5 x 22.4 litres of O2
for 12.4 gms of P4 we need
\(\frac{5 \times 22.4}{124} \times \frac{12.4}{1}\)
\(\frac{22.4}{2}\) = 11.2 litres
copper, zinc and nickel
aluminium and copper
copper and zinc
tin and zinc
tin and copper
Correct answer is E
No explanation has been provided for this answer.
Two metallic ions associated with hard water are
copper and zinc
magnesium and silver
calcium and magnesium
potassium and tin
sodium and lead
Correct answer is C
No explanation has been provided for this answer.
Hydrogenation may be effected by
the removal of hydrogen from an alkane in the presence of a catalyst
the addition of hydrogen to an alkane in the presence of a catalyst
the addition of hydrogen to an alkyne
the removal of hydrogen from an alkyne
the addition of hydrogen to an ethyl alcohol
Correct answer is C
No explanation has been provided for this answer.
The solution of a sample in a tube will be identified as a chloride if it gives
a white precipitate on addition of AgNO3 and barium chloride solutions
a white precipiate when acidified with HCI, and then AgNO3 solution added
a white precipitate when acidified with dilute HNO3 and then AgNO3 solution added
a white precipitate when acidified with dilute H2SO4 and then barium nitrate solution added
a pungent smell of chlorine gas when dilute HCI and MnO2 are added
Correct answer is C
No explanation has been provided for this answer.