Chemistry - Principles related to Practical Chemistry
Exam Duration: 45 Mins Total Questions : 30
The number of electrons in 3d shell for element with atomic number 26 is
- (a)
4
- (b)
6
- (c)
8
- (d)
10
With which of the following configurations the lowest value of first IE is associated?
- (a)
1s2 2s2 2p6 3s1
- (b)
1s2 2s2 2p5
- (c)
1s2 2s2 2p6
- (d)
1s2 2s2 2p6 3s23p2
The octet rule is not valid for the molecule
- (a)
CO2
- (b)
H2O
- (c)
O2
- (d)
CO
Which type of crystal should be softest and have the lowest m.ps.
- (a)
moleculer crystals
- (b)
metallic crystals
- (c)
ionic crystals
- (d)
negative crystals
A solution of 200 ml of 1 M KOH is added to 200 ml of 1 M HCl and the mixture is well shaken. The rise in temperature T1 is noted. The experiment is repeated by using 50 ml of each solution and increase in temperature T2 is again noted. Which of the following is correct?
- (a)
T1 = T2
- (b)
T2 is twice as large as T1
- (c)
T1 is twice as large as T2
- (d)
T1 is four twice as large as T2
The solution of sodium carbonate has pH
- (a)
greater than 7
- (b)
less than 7
- (c)
equal to 7
- (d)
equal to zero
For the reaction :
\({ CHCl }_{ 3 }(g)\quad +\quad { Cl }_{ 2 }(g)\quad \longrightarrow \quad { CCl }_{ 4 }(g)+HCl(g)\) the rate is given by the expression: k[CHCl3] [Cl2]1/2 The dimensions of the rate constant in this case would be
- (a)
s-1
- (b)
mol-1/2 L1/2 s-1
- (c)
L mol-1 s-1
- (d)
L2 mol-2 s-1
Alum helps in purifying water by
- (a)
forming complex with clay particles
- (b)
the sulphate present in alum combines with the dirt and removes it
- (c)
aluminium coagulates the mud particles
- (d)
making mud water soluble
Hydrogen peroxide in aq. soln. decomposes on warming according to the equation \({ 2H }_{ 2 }{ O }_{ 2 }\quad (aq)\rightarrow \quad { 2H }_{ 2 }O\quad (l)\quad +{ O }_{ 2 }\quad (g)\) If one mole of gas occupies 24 cm3 and 100 cm3 of an XM solution of H2O2 produces 3 dm3 of O2 , then X is
- (a)
0.25
- (b)
2.5
- (c)
5.5
- (d)
6.5
The extraction of which of the following metals involves bessemerisation?
- (a)
Fe
- (b)
Ag
- (c)
Al
- (d)
Cu
When 50% H2SO4 is electrolysed the first product formed is
- (a)
Caro's acid
- (b)
Maeshall's acid
- (c)
Pyrosulphuric acid
- (d)
Hydrogen peroxid
The catalyst used in the manufacture of sulphide acid by contact process is
- (a)
finley divided iron
- (b)
molebdenum
- (c)
nitrous oxide
- (d)
vanadium pentoxide
In the above question the coordination number of platinum is
- (a)
+2
- (b)
+4
- (c)
+6
- (d)
-2
Which of the following is not a nucleophilic reagent?
- (a)
RMgBr
- (b)
LiALH4
- (c)
>0:
- (d)
H2O2
An example of an electrophilic substitution is
- (a)
chlorination of methane
- (b)
dehydration of ethanol
- (c)
nitration of benzene
- (d)
polymerisation of ethylene
Compound 'A' C5H10O forms a phenyl hydrazone and gives a negative Tollen's reagent test and iodoform test. on reduction with Zn-Hg/HCl, compound 'A' is gives n-pentane. the compound 'A' is
- (a)
Primary alcohol
- (b)
aldehyde
- (c)
secondary alcohal
- (d)
ketone
In the following reaction,
\({ N }_{ 2 }(g)+3{ H }_{ 2 }(g)\rightarrow 2{ NH }_{ 3 }(g)\)
Calculate the moles of NH3 obtained when 2 moles of N2 react with 3 moles of H2 .
- (a)
2 mol
- (b)
4 mol
- (c)
1 mol
- (d)
6 mol
In the extraction of chlorine by electrolysis of brine,
- (a)
oxidation of Cl- ion to chlorine gas occurs
- (b)
reduction of Cl- ion to chlorine gas occurs
- (c)
for overall reaction, \(\Delta G^0\) has negative value
- (d)
a displacement reaction takes place
Brine is electrolysed by using inert electrodes. The reaction at anode is
- (a)
Cl-(aq) \(\rightarrow\) \(\frac{1}{2}\)Cl2(g) + e-; \({ E }_{ cell }^{ \circleddash }=1.36 \ \ V\)
- (b)
2H2O(l) \(\rightarrow\) O2(g) + 4H+ + 4e-; \({ E }_{ cell }^{ \circleddash }=1.23 \ \ V\)
- (c)
Na+(aq) + e- \(\rightarrow\) Na(s); \({ E }_{ cell }^{ \circleddash }=2.71 \ \ V\)
- (d)
H+(aq) + e- \(\rightarrow\) \(\frac{1}{2}\)H2(g); \({ E }_{ cell }^{ \circleddash }=0.00 \ \ V\)
The hybridisation of orbitals of N atom in NO3-, NO2+ and NH4+ respectively are
- (a)
sp2,sp,sp3
- (b)
sp,sp3,sp2
- (c)
sp2,sp3,sp
- (d)
sp,sp2,sp3
In context of the lanthanoids, which of the following statements is not correct?
- (a)
There is a gradual decrease in the radii of the members with increasing atomic number in the series.
- (b)
All the members exhibit +3 oxidation state.
- (c)
Because of similar properties the separation of lanthanoids is not easy
- (d)
Availability of 4f electrons results in the formation of compounds in +4 state for all the members of the series.
Which of the following hydroxides is/are soluble in excess of NaOH?
- (a)
Cr(OH)3
- (b)
Ca(OH)2
- (c)
Zn(OH)2
- (d)
Fe(OH)3
Select the incorrect statement
- (a)
Surface water contains a lot of organic matter, mineral nutrients and radioactive materials
- (b)
Oil slick in sea water decreases BOD value
- (c)
Oil spill in sea water causes heavy damage to fishery
- (d)
Main reason for river water pollution is industrial and domestic sewage discharge
The acids, HCOOH and CH3COOH are distinguished by
- (a)
reaction with Na metal
- (b)
reaction with NaOH
- (c)
reaction with Tollen's reagent
- (d)
reaction with Schiff's reagent
Under what conditions of temperature and pressure, the formation of atomic hydrogen from molecular hydrogen will be favoured more?
- (a)
High temperature and low pressure
- (b)
Low temperature and low pressure
- (c)
High temperature and high pressure
- (d)
Low temperature and high pressure
Li metal is the strongest reducing agent due to its
- (a)
heat of sublimation
- (b)
ionisation energy
- (c)
hydration energy
- (d)
None of the above
A reaction involving two different reactants can never be
- (a)
bimolecular reaction
- (b)
second order reaction
- (c)
first order reaction
- (d)
unimolecular reaction