CBSE 12TH CHEMISTRY - Online Test
Q1. Which of the following ore contains both Mg and Ca?
Answer : Option B
Explaination / Solution:
Dolomite is MgCO3 .CaCO3 .
Q2. A metal X on heating in nitrogen gas gives Y. Y on treatment with water gives a colourless gas which when passed through copper sulphate solution gives a blue colour. Y is
Answer : Option B
Explaination / Solution:
Mg3N2 reacts with water to evolve NH_3. Which reacts with copper ion to form blue color complex.
Q3. What is the nature of glucose – glucose linkage in starch that makes its so susceptible to acid hydrolysis
Answer : Option A
Explaination / Solution:
Glucose glucose linkage in starch is acetal linkage.
Q4. Fe3O4is
Answer : Option B
Explaination / Solution:
is Ferromagnetic.
Q5.
In the reaction,
A is
A is
Answer : Option B
Explaination / Solution:
Q6. According to Werner’s theory, the secondary valences of the central atom correspond to its
Answer : Option D
Explaination / Solution:
According to Werner’s theory CN is equal to secondary valency.
Q7. For making distinction between 2 – pentanone and 3 – pentanone the reagent to be employed is
Answer : Option D
Explaination / Solution:
2-pentanone will give iodoform but 3-pentanone will not give.
Q8. Potassium metabisulphite is a food – preservative as it is
Answer : Option D
Explaination / Solution:
produces
Q9. Which of the following electrolytic solutions has the least specific conductance?
Answer : Option D
Explaination / Solution:
Specific conductance decreases with dilution because of decrease in the number of ions per unit volume.
Q10. The synthesis of 3 – octyne is achieved by adding a bromoalkane into a mixture of sodium amide and an alkyne. The bromoalkane and alkyne respectively are
Answer : Option D
Explaination / Solution:
NaNH2 is very strong base it will abstract H from alkyne and then substitution reaction will occur.
