CBSE 11TH CHEMISTRY - Online Test
Q1. Lines in the hydrogen spectrum which appear in the infrared region of the electromagnetic Spectrum, then they are called as
Answer : Option B
Explaination / Solution:
The Lyman series lies in the ultraviolet, whereas the Paschen, Brackett, and Pfund series lie in the infrared.
Q2. Hydrogenation of vegetable oil using nickel as catalyst gives edible fats. Choose the appropriate one given below.
Answer : Option A
Explaination / Solution:
Vanaspati ghee is manufactured from vegetable or seed oil by a process called 'hydrogenation'.
Vegetable Oil is a viscous liquid, and contains unsaturated fatty acids, upon hydrogenation it is are converted to saturated fatty acids to form vanaspati ghee which is solid/semi solid in nature.
For quick and easy hydrogenation, catalyst like Ni, Pt which are capable of adsorbing hydrogen are used.
Q3. The equilibrium constant for a reaction is 10. What will be the value of , T = 300 K.
Answer : Option A
Explaination / Solution:
= -RTln K
Q4. Which one of the following conversions involve change in both hybridization and shape?
Answer : Option C
Explaination / Solution:
BF3 has sp2 hybridisation and its shape is triangular planar While BF4- has sp3 hybridisation and shape is tetrahedral.
Q5. Calcium oxide is prepared on a commercial scale by using
Answer : Option C
Explaination / Solution:
Lime stone and rotary kiln is used in prepation of CaO.
Q6. In general, in the molecules containing multiple bonds,_____ provide the most reactive centres. Choose the most appropriate one.
Answer : Option A
Explaination / Solution:
pie bonds are the most reactive centers.
Q7. A mixture of dihydrogen and dioxygen at one bar pressure contains 20% by weight of dihydrogen. Calculate the partial pressure of dihydrogen.
Answer : Option C
Explaination / Solution:
P=P1+P2 (Daltons Law of partial pressure).
Q8. In which of the following compounds, an element exhibits two different oxidation states.
Answer : Option B
Explaination / Solution:
Q9.
For the reaction
Which is the limiting reagent for this reaction ?
Answer : Option B
Explaination / Solution:
Chemical reactions rarely occur completely when exactly the right amounts of reactants are taken to react together to yield products as per its stoichiometry .One of the reactants will be used up ,before another runs out.Thus , the reactant which is consumed first is known as limiting reagent
For the given reaction ,
2 N2 H4 (l) + N2 O4 (l) ------> 3 N2 (g) + 4 H2 O (l)
as per its stoichiometry , if only the right and exact amount of N2 O4 is taken , the reaction may not go to completion .As such it would be consumed first & is , therefore , the limiting reagent.
Q10. is dissolved in water to give 500 mL of solution. The pH of the solution is
Answer : Option C
Explaination / Solution:
pOH=-log[] and here [OH-] = (0.3 x 1000)/(74 x500) While pH=14-pOH
