CBSE 11TH CHEMISTRY - Online Test
Q1. During hearing of a court case, the judge suspected that some changes in the documents had been carried out. He asked the forensic department to check the ink used at two different places. According to you which technique can give the best results?
Answer : Option A
Explaination / Solution:
TLC will give the best results.
Q2.
At, the density of a certain oxide of a gas at 2 bar is same as that of dinitrogen at 5 bar. What is the molecular mass of the oxide?
Answer : Option C
Explaination / Solution:
PV=(m/M)RT
Q3. Which of the following statements is correct?
Answer : Option A
Explaination / Solution:
Ice and water kept in a perfectly insulated thermos flask (no exchange of heat between its contents and the surroundings) at 273K and the atmospheric pressure are in equilibrium state and the system shows interesting characteristic features. We observe that the mass of ice and water do not change with time and the temperature remains constant.
Q4. Electrochemical processes for extraction of highly reactive metals and non-metals involves one of the following. Choose the most appropriate option.
Answer : Option D
Explaination / Solution:
It involves redox process.
Q5.
The gram molar mass of is
Answer : Option A
Explaination / Solution:
The gram molar mass of Ca CO3 is calculated by ,
(i) adding up the atomic masses of Ca , C & 3 O atoms & ,
(ii) representing the molar mass in grams.
Thus , gram molar mass of Ca C O3
= [ atomic mass of Ca , atomic mass of C , 3 x atomic mass of O ]
=
= ( 40 + 12 + 48 ) g
=100g
It should be noted that ,
atomic mass of Ca
= 12
atomic mass of C
= 12
atomic mass of O
= 16
Q6. The increasing order of reduction of alkyl halides with zinc and dilute HCl is
Answer : Option C
Explaination / Solution:
As we move from I to Br to Cl,atomic size decreases,it becomes difficult to release the halogen as the bond length decreases.Hence I- is the best leaving group among halogens and reacts the fastest.
Q7. of combustion of methane is - X kJ . The value of is
Answer : Option A
Explaination / Solution:
CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l)
We know, RT
Δng is negative as product water in combustion reaction is in liquid state.
This implies ΔHo will be more negative than ΔUo
Hence, ΔHo < ΔUo
Q8. To which block of elements in the periodic table belongs?
Answer : Option D
Explaination / Solution:
d-block element have the general outermost electronic configuration as (n-1)d1-10 ns0-2.
Q9. One of the following scientists was the first to discover electron
Answer : Option B
Explaination / Solution:
Electron was discovered by J. J. Thomson in 1897 when he was studying the properties of cathode ray. J. J. Thomson won Nobel Prize in 1906 for discovering the elementary particle electron.
Q10. Which of these is not released from burning fossil fuels?
Answer : Option C
Explaination / Solution:
Copper oxide can never be released during burning of fossil fuels because they do not contain copper in it which would be released as copper oxide after combustion.
