CBSE 12TH CHEMISTRY - Online Test
Q1. Activation energy of a reaction is
Answer : Option C
Explaination / Solution:
Activation energy is minimum energy required for reactant to get converted to product.
Q2. The number of phases in colloidal system are
Answer : Option A
Explaination / Solution:
Dispersed phase, dispersion medium
Q3. Protein is.
Answer : Option D
Explaination / Solution:
Protein is condensation polymer.
Q4.
Mark the correct order of decreasing acid strength of the following compounds.
Answer : Option B
Explaination / Solution:
B will be most acidic because of –M effect of NO2 . Followed by d, in d –I effect of NO2 operates only. Then c will come as –I of OCH3 < - I of NO2 and least will be e because of +M effect of OCH3 that will decrease the acidity
Q5. 6.3 g oxalic acid is used to make 250 mL aqueous solution .The volume of 0.1N NaOH solution required to neutralize completely 10 mL of this solution is
Answer : Option C
Explaination / Solution:
Q6. In a coupling reaction, the azo products obtained, involve an
Answer : Option D
Explaination / Solution:
In coupling reaction Diazonium salt to act as a electrophile and –N=N- bond forms.
Q7. Metal halides are found in lakes and seas because
Answer : Option A
Explaination / Solution:
Metal halides are soluble in water.
Q8. The reagent used to distinguish between H2O2 and O3 is
Answer : Option B
Explaination / Solution:
H2O2 can decolorize the color of KMnO4 .
Q9. Which of the following polymers have tetrafluoroethene monomer units?
Answer : Option B
Explaination / Solution:
Teflon is used in making non stick utensil surface.
Q10. The unit cell of a substance has cations A+ at the corners of the unit cell and the anions B – in the center. The simplest formul of the substance is
Answer : Option D
Explaination / Solution:
Contribution of A= Contribution of B = 1. Formula is AB.
