Chemistry Practice Questions
Exam Duration: 120 Mins Total Questions : 100
Carbon occurs as a mixture of \(_{ 6 }^{ 12 }C\) and \(_{ 6 }^{ 13 }C\). The atomic mass of \(_{ 6 }^{ 12 }C\) is exactly 12 amu by definition and the atomic mass of \(_{ 6 }^{ 13 }C\) is 13.003 amu. If the average atomic mass of carbon is 12.001 amu, the atom percent of \(_{ 6 }^{ 12 }C\) in natural carbon would be
- (a)
99.2
- (b)
98.9
- (c)
94.6
- (d)
99.0
The wave number of the yellow light of the wave length of 5800 \(\mathring { A } \) emitted by the sodium lamp would be
- (a)
5.17X 1014s-1
- (b)
1.72X 106m-1
- (c)
17.2X 107m-1
- (d)
17.2X 108m-1
Subsidiary quantum number specifies
- (a)
size of orbital
- (b)
shape of orbital
- (c)
orientation of orbital in space
- (d)
nuclear stability
Which quantum number is sufficient to describe the electron in hydrogen atom?
- (a)
l
- (b)
n
- (c)
m
- (d)
s
With increasing principle quantum number, the energy difference between adjacent energy levels in H atom
- (a)
decreases
- (b)
increases
- (c)
remains constant
- (d)
decrease for low value of Z and increase for higher value of Z
The properties of the elements are the periodic function of their atomic numbers.The statement is given by
- (a)
N.Bohr
- (b)
J.W.Dobereiner
- (c)
D.I.Mendeleev
- (d)
H.G.J.Moseley
In which of the following groups of periodic table mp/bp increase down the group?
- (a)
Group 1
- (b)
Group 2
- (c)
Group 17
- (d)
Group 13
Atomic radii of flourine and neon in angstrom units are given by
- (a)
0.72, 1.60
- (b)
1.60, 1,60
- (c)
0.72, 0.72
- (d)
None of these
Atomic orbitals of carbon in graphite have
- (a)
sp hybridisation
- (b)
sp2 hybridisation
- (c)
sp3 hybridisation
- (d)
dsp2 hybridisation
What is the hybrid orbital set in PF5?
- (a)
sp3
- (b)
sp4
- (c)
dsp3
- (d)
d2sp3
Homolytic fission of C-C bond in ethane (CH3-CH3) gives an intermediate in which carbon atom is
- (a)
sp3 hybridised
- (b)
sp2 hybridised
- (c)
sp hybridised
- (d)
sp2d hybridised
The maximum possible number of hydrogen bonds in which a water molecule can participate is
- (a)
4
- (b)
3
- (c)
2
- (d)
1
The geometric form of crystals is the result of orderly arrangement of
- (a)
molecules only
- (b)
ions only
- (c)
atoms only
- (d)
molecules,atoms or ions
Water(H2O) is liquid while hydrogen sulphide(H2S) is a gas because
- (a)
Water has higher molecular weight
- (b)
Hydrogen sulphide is a weak acid
- (c)
Sulpher has higher electronegativity than oxygen
- (d)
Water molecules associate through hydrogen bonding
To which one of the following Dalton's law of partial pressure is not applicable?
- (a)
SO2 and CO2 at room temperature
- (b)
N2 and H2 at room temperature
- (c)
SO2 and O2 at room temperature
- (d)
HCl and NH3 at room temperature
Silicon doped with arsenic is an example of which type of semiconductor?
- (a)
p-type
- (b)
n-type
- (c)
n, p type
- (d)
intrinsic
The molar heats of combustion of C2H4(g), C (graphite) and H2(g) are 310.62 kcal, 94.05 kcal and 68.32 kcal, respectively. The standard heat of formation of C2H4(g) would be
- (a)
+ 108.4 kcal
- (b)
- 54.2 kcal
- (c)
+ 54.2 kcal
- (d)
- 108.4 kcal
For the reaction at 400 K \(2NOCl(g)\rightleftharpoons 2NO(g)+{ Cl }_{ 2 }(g)\) (Given \({ \Delta H }^{ o }\rightleftharpoons 77.2kJ{ mol }^{ -1 },{ \Delta S }^{ o }\rightleftharpoons 112kJ{ mol }^{ -1 }\) at 400 K) the equilibrium constant Kp would be :
- (a)
2.95 \(\times\) 10-4
- (b)
1.95 \(\times\) 10-4
- (c)
3.95 \(\times\) 10-4
- (d)
4.95 \(\times\) 10-4
At constant temperature, the equilibrium constant (\(K_{p}\)) for the decomposition \(N_{2}O_{4}\rightleftharpoons 2NO_{2}\) is expressed by \(K_{p}={4x^{2}-P\over1-x^{2}}\), where p=pressure, x=extent of decomposition. Which of the following statement is true ?
- (a)
\(K_{p}\) increases with increase of p.
- (b)
\(K_{p}\) increases with increase of x.
- (c)
\(K_{p}\) increases with decrease of x.
- (d)
\(K_{p}\) remains constant with change in p and x.
The equlilibrium constant for the gaseous reaction A+B\(??\rightleftharpoons \)C+D is 100 at \(25^{o}\)C. Consider the following statement in this regard. If the initial concentrations of all the four species were 1.0 M, then the equilibrium concentration of
(1) A would be 0.182 mol and
(2) C would be 0.818 mol and
(3) D would be 1.818 mole
Of the statements
- (a)
1 and 2 are correct
- (b)
1 and 3 are correct
- (c)
2 and 3 are correct
- (d)
1,2 and 3 are correct
Which of the following is not used as Lewis acid?
- (a)
SnCI4
- (b)
FeCI3
- (c)
KCI
- (d)
BF3
A 50 ml solution of pH=1 is mixed with a 50 ml solution of pH=2. The pH of the mixture will be nearly , given log 55=0.74.
- (a)
0.76
- (b)
1.26
- (c)
1.7
- (d)
2.26
The H+ conc. (mol L-1) of a solution whose pH is 5.4, would be approximately
- (a)
4*10-6
- (b)
2*10-6
- (c)
1*10-6
- (d)
3*10-2
In the reaction \(Zn+{ H }_{ 2 }{ SO }_{ 4 }\longrightarrow Zn{ SO }_{ 4 }+{ H }_{ 2 }\)
- (a)
Zn is oxidised
- (b)
Zn is reduced
- (c)
\({ H }_{ 2 }{ SO }_{ 4 }\) is oxidised
- (d)
\(Zn{ SO }_{ 4 }\) is reduced
In the reaction \(3{ Br }_{ 2 }+6{ CO }_{ 3 }^{ 2- }+3{ H }_{ 2 }O\longrightarrow 5{ Br }^{ - }+{ BrO }_{ 3 }^{ - }+6HC{ O }_{ 3 }^{ - }\)
- (a)
bromine is reduced and carbonate is oxidised
- (b)
bromine is oxidised and carbonate is oxidised
- (c)
bromine is reduced as well as oxidised
- (d)
bromine is neither reduced nor oxidised
Which one of the following is the strongest oxidising agent?
- (a)
F2
- (b)
Cl2
- (c)
Br2
- (d)
I2
If the observed and the theoretical molecular mass of NaCl aer found to be 31.80 and 58.50, then the degree of dissociation of NaCl is approximately
- (a)
80%
- (b)
90%
- (c)
84%
- (d)
99%
Which element is the end product of every of every natural radioactive series?
- (a)
Pb
- (b)
Sn
- (c)
C
- (d)
Bi
The end product of (4n+2) disintegration series is
- (a)
\(_{ 82 }^{ 204 }{ Pb }\)
- (b)
\(_{ 82 }^{ 208 }{ Pb }\)
- (c)
\(_{ 82 }^{ 206 }{ Pb }\)
- (d)
\(_{ 82 }^{ 209 }{ Pb }\)
The volume of co2 evoled on complete combustion of 1 mole of ethylene in excess oxygen in litres is
- (a)
22.4
- (b)
44.8
- (c)
2.24
- (d)
NONE OF THESE
The empirical formula of a compound is CH2, 1 mole of the compound has mass 14 g.its moleculer formula is
- (a)
CH2
- (b)
C2H4
- (c)
C3H8
- (d)
C3H6
Chloroform and Benzene form a pair of miscible liquids. These can be seperated by
- (a)
Sublimation
- (b)
Filteration
- (c)
a seperating funnel
- (d)
distillation
If on adding FeCl3 solution to acidified lassagine solution, a blood red colouration is produced, it indicates the presence of
- (a)
S
- (b)
N
- (c)
N and s
- (d)
S and CI
19.7 kg of gold was recovered from a smuggler. How many atoms of gold were recovered ? (Au = 197)
- (a)
100
- (b)
6.02 x 1023
- (c)
6.02 x 1024
- (d)
6.02 x 1025
Which of the following has least mass?
- (a)
2 g-atom of nitrogen
- (b)
3 x 1023 atoms of C
- (c)
1 mole of S
- (d)
7.0 of Ag
Chemical leaching is useful in the concentration of
- (a)
Copper Pyrites
- (b)
bauxite
- (c)
Cassiterite
- (d)
galena
Nitrogen has atomic number 7 and oxygen an atomic number 8. The total number of electrons in the nitrate ion (NO3-) is
- (a)
15
- (b)
81
- (c)
32
- (d)
63
The angular momentum of elctrons in the hydrogen atom that may be possible is
- (a)
h/\(\pi\)
- (b)
h\(\pi\)
- (c)
h/4\(\pi\)
- (d)
2h
Helium was first detected spectroscopically by
- (a)
Cavendish
- (b)
Lockyer
- (c)
Ramsay
- (d)
Rutherford
White phosphorus reacts with caustic soda. The products are PH3 and NaH2PO2. This reaction is an example of
- (a)
oxidation
- (b)
reduction
- (c)
oxidation and reduction
- (d)
None of the above
Which one the following statement about KClO3 is wrong?
- (a)
It is a reducing agent
- (b)
It liberates Cl2 when treated with I2 solution
- (c)
It is prepared by passing Cl2 gas into KOH solution
- (d)
It give soxygen gas when heated alone
Which one of the following statement is wrong about aluminium
- (a)
It is the most abundant metal in the earth crust
- (b)
It dissolves readily in concentrated nitric acid
- (c)
It is affected by caustic soda solution
- (d)
It is a good reducing agent
Amongst the following compounds, the weakest base is
- (a)
NaOH
- (b)
KOH
- (c)
Mg(OH)2
- (d)
Ca(OH)2
Percentage of carbon is maximum in
- (a)
peat
- (b)
lignite
- (c)
bituminous
- (d)
anthracite
Number of \(\sigma \) -bonds in toluene would be
- (a)
8
- (b)
10
- (c)
12
- (d)
15
The substance represented by the formulae
\(\quad\quad COOH\\ \quad \quad \quad \quad |\\ { H }_{ 2 }N-C-H\\ \quad \quad \quad \quad |\\ H\quad -C-\quad OH\\ \quad \quad \quad \quad |\\ \quad \quad \quad C{ H }_{ 3 }\) and \(\quad\quad\quad COOH\\ \quad \quad \quad \quad |\\ { H }-\quad C \quad -N{ H }_{ 2 }\\ \quad \quad \quad \quad |\\ HO-\quad C-H\\ \quad \quad \quad \quad |\\ \quad \quad \quad C{ H }_{ 3 }\)
- (a)
are enantiomers
- (b)
are geometric isomers
- (c)
are conformational isomers
- (d)
are identical molecules
which one of the following is optically active?
- (a)
\(C{ H }_{ 3\quad \quad \quad }\quad CO-NH\quad \quad \quad\quad C{ H }_{ 3\quad \quad \quad }\quad \\ \quad \quad \diagdown \quad \quad \diagup \quad \quad \quad \quad \quad \diagdown \quad \quad \quad \diagup \\ \quad \quad \quad \quad C\quad \quad \quad \quad \quad \quad \quad \quad C\\ \quad \quad \diagup \quad \quad \diagdown \quad \quad \quad \quad \quad \diagup \quad \quad \diagdown \\ H\quad \quad \quad \quad \quad H-CO\quad \quad \quad \quad \quad H\)
- (b)
\(C{ H }_{ 3\quad \quad \quad }\quad CO-NH\quad \quad \quad \quad \quad H\\ \quad \quad \diagdown \quad \quad \diagup \quad \quad \quad \quad \quad \diagdown \quad \quad \quad \diagup \\ \quad \quad \quad \quad C\quad \quad \quad \quad \quad \quad \quad \quad C\\ \quad \quad \diagup \quad \quad \diagdown \quad \quad \quad \quad \quad \diagup \quad \quad \diagdown \\ H\quad \quad \quad \quad NH-CO\quad \quad \quad \quad \quad C{ H }_{ 3\quad \quad \quad }\)
- (c)
\(C{ H }_{ 3 }-C{ H }_{ 2 }-COOH\)
- (d)
\(\quad\quad COOH\\ \quad \quad \quad \quad |\\ \quad H-C-OH\\ \quad \quad \quad \quad |\\ \quad H-C-OH\\ \quad \quad \quad \quad |\\ \quad \quad COOH\\ \)
Which one of the following substance will react with ammonical silver nitrate?
- (a)
1-butyne
- (b)
2-butyne
- (c)
1-butene
- (d)
2-butene
An aqueous solution of a substance on electrolysis gives ethane.The substance is
- (a)
acetic acid
- (b)
acetamide
- (c)
potassium acetate
- (d)
ethyl acetate
8.6 g of n-hexane on combustion with excess of O2 produce CO2 equal to
- (a)
0.6 mole
- (b)
1.2mole
- (c)
12 moles
- (d)
2 moles
Which one of the following reagents can bring about RCHO -> RCH2OH transformation?
- (a)
Sn and HCl
- (b)
H2 and Pt
- (c)
LiAiH4 and ether
- (d)
Na and alcohol
Which one of the following acids reduces ammonical silver nitrate?
- (a)
acetic acid
- (b)
formic acid
- (c)
n-butryric acid
- (d)
propionic acid
Which branched chain isomer of the hydrocarbon with molecular mass 72 give only one isomer of mono substituted alky1 halide?
- (a)
neopentane
- (b)
isohexane
- (c)
neohexane
- (d)
tertiany buty1 chloride
The length of the chain of the polymer can be controlled during polymerisation by the addition of a reagent called
- (a)
toners
- (b)
inhibitors
- (c)
initiators
- (d)
poison
Which one of the following is not present in RNA?
- (a)
uracil
- (b)
thymine
- (c)
ribose
- (d)
phosphate
Number of significant figures in 78.000 g, 0.0206 g and 3.002 g are
- (a)
3, 4, 5
- (b)
2, 5, 4
- (c)
3, 3, 4
- (d)
5, 3, 4
A sample of AlF3 contains 3.0 x 1024 F- ions. The number of formula units of this sample are
- (a)
9.0 x 1024
- (b)
3.0 x 1024
- (c)
0.75 x 1024
- (d)
1.0 x 1024
The period number in the long form of the periodic table is equal to
- (a)
magnetic quantum number of any element of the period
- (b)
atomic number of any element of the period
- (c)
maximum principal quantum number of any element of the period
- (d)
maximum azimuthal quantum number of any element of the period
Vapour density of a gas is 11.2. Volume occupied by 2.4 g of this at STP will be
- (a)
2.4 L
- (b)
2.24 L
- (c)
22.4 L
- (d)
11.2 L
Natural hydrogen consists of 80% \(H_2\) and 20% \(D_2\) by mass. The number of ideal diffusion steps required to produce 94.11% \(H_2\) from mixture are
- (a)
12
- (b)
8
- (c)
6
- (d)
4
Which of the following represents correct order of first ionisation energy?
- (a)
K > Na > Li
- (b)
Be > Mg > Ca
- (c)
B > C > N
- (d)
Ce > Si > C
If the density of methanol is 0.793 kg L-1. What is volume needed for making 2.5 L of its 0.25 M solution?
- (a)
25.22 L
- (b)
2500 mL
- (c)
25.22 mL
- (d)
2500 L
Which one of the following set of cations represents a collection of isoelectronic species?
- (a)
K+, Cl-, Ca2+, Sc3+
- (b)
Ba2+, Sr2+, K+, S2-
- (c)
N3-, O2-,F-,S2-
- (d)
Li+,Na+,Mg2+,Ca2+
Which of the following hybridisation is not possible?
- (a)
sp3
- (b)
sp3d3
- (c)
sd3
- (d)
None of the above
Which of the following show correct structure of ICl2 ?
- (a)
- (b)
- (c)
- (d)
None of these
Identify the incorrect statement about Al2(SO4)3
- (a)
It is a white salt
- (b)
on adding NaOH solution to its aqueous solution, a precipitate is formed which get dissolve in excess of NaOH solution
- (c)
with lead acetate solution also, it gives a ppt.
- (d)
with silver nitrate, its aqueous solution gives a ppt.
Total volume of atoms present in a face-centred cubic unit cell of a metal is (r is atomic radius)
- (a)
\(16\over 3\pi r^3\)
- (b)
\({20\over 3}\pi r^3\)
- (c)
\({24\over 3}\pi\ r^3\)
- (d)
\({12\over 3}\pi r^3\)
Smog is formed in the places having
- (a)
low temperature
- (b)
high temperature
- (c)
excessive SO2 in the air
- (d)
excessive NH3 in the air
The spin angular momentum of an electron is given by
- (a)
\(\mu_s=\sqrt{s(s+1)}\frac{h}{2\pi}\)
- (b)
\(s=s\frac{h}{2\pi}\)
- (c)
\(s=\frac{3}{2} \times \frac{h}{2\pi}\)
- (d)
None of the above
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 use at two different places. According to you which technique can give the best results?
- (a)
Column chromatography
- (b)
Solvent extraction
- (c)
Distillation
- (d)
Thin layer chromatography
In a fuel cell, methanol is used as fuel and oxygen gas is used as an oxidiser. The reaction is \(CH_3OH(l)+{3\over 2}O_2(g)\rightarrow CO_2(g)+2H_2O(l)\)
and \(CO_2(g)\) are \(-166.2,-237.2\) and \(-394.4\ kJ\ mol^{-1}\) respectively.
If the standard enthalpy of combustion of methanol is \(-726\ kJ\ mol^{-1},\) efficiency of the fuel cell will be
- (a)
90%
- (b)
97%
- (c)
80%
- (d)
87%
Which of the following is not the property of interhalogen compounds?
- (a)
They are more reactive but than halogen
- (b)
They are quite unstable but none of them is explosive
- (c)
They are covalent in nature
- (d)
They are weak oxidising agents
Hydroboration - oxidation of propene yield
- (a)
CH3CH2CHO
- (b)
CH3CHOHCH3
- (c)
CH3CHOHCH2OH
- (d)
CH3CH2CH2OH
Hundiecker reaction is an example of
- (a)
decarboxylation
- (b)
debromination
- (c)
decarboxylation and bromination
- (d)
bromination
An antibiotic effective in treatment of pneumonia, bronchitis etc., is
- (a)
penicillin
- (b)
patalin
- (c)
chloromycetin
- (d)
tetracycline
Insulin production and its action in human body are responsible for the level of diabeties. This compound belongs to which of the following categories?
- (a)
A coenzyme
- (b)
A hormone
- (c)
An enzyme
- (d)
An antibiotic
Oral contraceptive drugs contain
- (a)
mestranol
- (b)
norethindrone
- (c)
Both (a) and (b)
- (d)
None of the above
The number of constitutional isomers of the formula C5H11Br is
- (a)
4
- (b)
8
- (c)
6
- (d)
10
Which detergents will cause maximum pollution?
- (a)
- (b)
- (c)
detergents are always pollution free
- (d)
CH3CH(C4H9)-CH2CH2CH(C4H9)(CH2)3CH(C4H9)CH2CH2SO3Na
Asthma patients use a mixture of ........ for respiration.
- (a)
O2 and Kr
- (b)
O2 and He
- (c)
O2 and Ar
- (d)
O2 and Ne
Benzylamine may be alkylated as shown in the following equation CHCHNH+R-X 6H5CH2NH 2+R-X \(\longrightarrow \)C6H5CH 2NHR. Which of the following alkylhalides is best suited for this reaction through SN1 mechanism?
- (a)
CH3Br
- (b)
C6H5 Br
- (c)
C6H5CH2Br
- (d)
C2H5Br
The oxidation number of chromium in potassium dichromate is
- (a)
+2
- (b)
+4
- (c)
+6
- (d)
+8
Which of the following is not general characteristic of equilibrium involving physical processes?
- (a)
Equilibrium is possible only in a closed system at a given temperature.
- (b)
All measurable properties of the system remain constant
- (c)
All the physical processes stop at equilibrium
- (d)
The opposing processes occur at the same rate and there is dynamic but stable condition.
Which of the following on heating with aqueous KOH, produces acetaldehyde?
- (a)
CH3COCl
- (b)
CH3CH2Cl
- (c)
CH2ClCH2Cl
- (d)
CH3CHCl2
Tritium is obtained by
- (a)
nuclear reactions
- (b)
passing steam over heated C
- (c)
action of NaOH on Al
- (d)
action of \(H_2SO_4\) on Zn
Among the following acids which has the lowest pKa value?
- (a)
CH3COOH
- (b)
HCOOH
- (c)
(CH3)2CH-COOH
- (d)
CH3CH2COH
Mass percentage of deuterium in heavy water is
- (a)
same as that of protium in water
- (b)
11.1
- (c)
20.0
- (d)
cannot be predicted
Considering the basic strength of amines in aqueous solution, which one has the smallest pKb value
- (a)
(CH3)2NH
- (b)
CH3NH2
- (c)
(CH3)3N
- (d)
C6H5NH2
Consider the reaction equilibrium \(2SO_{ 2 }(g)+O_{ 2 }(g)\rightleftharpoons 2SO_{ 3 }(g);\Delta H^{ o }=-198kJ\) on the basis of Le-Chatelier's principle, the condition favourable or the forward reaction is
- (a)
lowering of temperature as well as pressure
- (b)
increasing temperature as well as pressure
- (c)
lowering the temperature and increasing the pressure
- (d)
any value of temperature and pressure
An alloy of K + Na is
- (a)
used in specially designed thermometers
- (b)
liquid at room temperature
- (c)
Both (a) and (b)
- (d)
None of the above
Gas mask is prepared on the basis of adsorption because
- (a)
it causes adsorption of poisonous gases on activated charcoal
- (b)
it causes absorption of gaseous particles
- (c)
it increases oxygen molecule around the atmosphere by decreasing concentration of poisonous gases
- (d)
Both (a) and (c)
When a lead storage battery is charge it acts as
- (a)
primary cell
- (b)
a galvanic cell
- (c)
a concentration cell
- (d)
an electrolytic cell
A certain current liberates 0.500 g of H in 2.00 hr. How 2 in 2.00 hr. How many gram of oxygen can be liberated by the same current in the same time?
- (a)
0.500 g
- (b)
8.00 g
- (c)
4.00 g
- (d)
16.00 g
The ionisation constant of ammonium hydroxide is 1.77 x 10-5 at 298 K. Hydrolysis constant of ammonium chloride is
- (a)
5.65 x 10-10
- (b)
6.50 x 10-12
- (c)
5.65 x 10-13
- (d)
5.65 x 10-12