test of chemistry - Thorpes Education

TEST OF CHEMISTRY
1.
2H2O H3O+ + OH–, Kw = 1 × 10–14 at 25° C, hence Ka is
(a) 1 × 10–14
(b) 5.55 × 10–13
–17
(c) 18 × 10
(d) 1.00 × 10–7
2.
Identify the correct order of acidic strengths of CO2, CuO, CaO, H2O
(a) CaO < CuO < H2O < CO2
(b) H2O < CuO < CaO < CO2
(c) CaO < H2O < CuO < CO2
(d) H2O < CO2 < CaO < CuO
3.
The compound that does not act as Lewis acid
(a) AlCl3
(b) BF3
(c) NH3
(d) FeCl3
4.
Which of the following mixture is not a buffer?
(a) NH3 + NH4Cl
(b) HC2H3O2 + NaOH in a 1 : 1mole ratio
(c) NH3 + HCl in a 2 : 1 mole ratio
(d) HC2H3O2 + NaOH in a 2 : 1mole ratio
5.
The precipitate of CaF2(Ksp = 1.7 × 10–10) is obtained when equal volumes of the following
are mixed
(a) 10–4 M Ca2+ + 10–4 M F–
(b) 10–2 M Ca2+ + 10–3 M F–
(c) 10–5 M Ca2+ + 10–3 M F–
(d) 10–3 M Ca2+ + 10–5 M F–
6.
How many grams of CaC2O4 will dissolve in distilled water to make one litre of saturated
solution ? (Ksp of CaC2O4 is 2.5 × 10–9mol2 lit–2)
(a) 0.0064g
(b) 0.0128 g
(c) 0.0032 g
(d) 0.0640 g
7.
The compound insoluble in acetic acid is
(a) calcium oxide
(b) calcium carbonate
(c) calcium oxalate
(d) calcium hydroxide
8.
In the following reaction,
[Cu(H2O)3 OH]++[Al(H2O)6]3+[Cu(H2O)4]2++ [Al(H2O)5OH]2+
(a) A is an acid, B is the base
(b) A is a base and B is the acid
(c) C is the conjugate acid of A and D is the conjugate base of B
(d) C is the conjugate base of A and D is the conjugate base of B.
9.
Which one is the strongest acid?
(a) ClO3 (OH)
(b) ClO2 (OH)
(c) SO (OH)2
(d) HCOO–
10.
The solubility of A2X3 is y mole dm–3. Its solubility product is
(a) 6y4
(b) 64 y4
5
(c) 36 y
(d) 108 y5
11.
The pKa of acetylsalicylic acid (aspirin) is 3.5. The pH of gastric juice in human stomach is
about 2–3 and the pH in the small intestine is about 8. Aspirin will be
(a) unionized in the small in testine and in the stomach
(b) completely ionized in the small intestin and in the stomach
(c) ionized in the stomach and almost un ionized in the small intestine
(d) ionizedin the small intestine and almost unionized in the stomach
12.
HCN behaves as a very weak acid in aqeous medium where as it acts as a strong acid in liquid
ammonia because
(a) Electronegativity of oxygen is greater than that of nitrogen
(b) Ionization energy of oxygen is less than that of nitrogen
(c) Proton affinity of water is less than that of ammonia
(d) Dipole moment of water is greater than that of ammonia
13.
Amongst Ni(CO)4, [Ni(CN)4]2– and NiCl42– :
(a) Ni (CO)4 and NiCl42– are diamagnetic and [Ni(CN)4]2– is paramagnetic
(b) NiCl42– and [Ni(CN)4]2– are dimagnetic and Ni(CO)4 is paramagnetic
(c) Ni(CO)4 and [Ni(CN)4]2– are dimagnetic and NiCl42– is paramagnetic
(d) Ni(CO)4 is dimagnetic and NiCl42– and [Ni(CN)4]2– are paramagnetic
14.
Which of the following is a complex compound?
(a) KCl.MgCl2.6H2O
(b) K2SO4.Al2(SO4)3.24H2O
(c) [Co(ONO)(NH3)5]SO4
(d) VO2Cl2
15.
A flask contains 12 g of a gas of relative molecular mass 120 at a pressure of 100 atm. It was
evacuated by meansof a pump until the pressure was 0.01 atm. Which of the following is the
best estimate of the number of molecules left in the flask (N0 = 6 × 1023 mole–1)
(b) 6 × 1018
(a) 6 × 1019
17
(c) 6 × 10
(d) 6 × 1013
16.
A gas will approach ideal behaviour at
(a) low temperature, low pressure
(b) low temperature, high pressure
(c) high temperature, low pressure
(d) high temperature, high pressure
17.
Milk is
(a) fat dispersed in milk (b) fat dispersed in water
(c) water dispersed in fat (d) water dispersed in oil
18.
The calculated bond order in H2+ ion is
(a) 0
(b) ½
(c) -1/2
(d) 1
19.
The formula of the compound is A2B5. The number of electrons in the outermost orbits of A
and B respectively are
(a) 6 and 3
(b) 5 and 6
(c) 5 and 2
(d) 2 and 3
20.
Which of the following contains a co-ordinate covalent bond ?
(a) N2H5+
(b) BaCl2
(c) HCl
(d) H2O
21.
Which is paramagnetic and coloured
(a) K2 Cr2 O7
(b) (NH4)2 [TiCl6 ]
(d) K3 [Cu (CN)4 ]
(c) VOSO4
22.
C – H bond distance is the longest in
(a) C2 H2
(b) C2 H4
(c) C2 H6
(d) C2 H2 Br2
23.
In presence of catalyst Ea is lowered by 2kcal at 27°C. Hence rate will be
(a) 20 times
(b) 14 times
(c) 28 times
(d) 2 times
24.
One mole of calcium phosphide on reaction with excess of water gives:
(a) Two moles of phosphoric acid
(b) One mole of phosphine
(c) Two mole ofphosphine
(d) One mole of phosphorus Pentoxide
25.
3 g of an oxide of a metal is converted to cholride completely and it yielded 5g of chloride.
The equivalent weight of the metal is:
(a) 33.25
(b) 3.325
(c) 12
(d) 20
26.
The half life time for the decomposition of a substance dissolved in CCl4 is 2.5hours. at
30°C. The amount of the substance left after 10 hours, if the initial weight of substance is 160
gm, is
(a) 5gm
(b) 10gm
(c) 15gm
(d) 20gm
27.
The solubility of AgI in NaI solution is less than that in pure water because,
(a) AgI forms complex with NaI
(b) of common ion effect
(c) solubility product of AgI is less than that of NaI
(d) the temperature of the solution decreases
28.
The pH of a solution obtained by mixing 50 ml. of 0.4 M HCl with 50 ml of 0.2
NaOH is
(a) – log 2
(b) – log 2 × 10–1
(c) 1.0
(d) 2.0
29.
pOH of 10–8 M solution of NaOH will be
(a) 8
(b) between 6 and 7
(c) between 7 and 8 (d) below 6
30.
Solubility of M2S salt is 3.5 × 10–6 then find out solubility product.
(b) 1.7 × 10–16
(a) 1.7 × 10–6
(c) 1.7 × 10–18
(d) 1.7 × 10–12
31.
The solubility of Fe(OH)3 is x mole L–1. Its Ksp would be
(b) 3 x4
(a) 9 x3
4
(c) 27 x
(d) 9 x4
32.
A weak acid HA has Ka= 10–6. What would be the molar ratio of this acid and its salt with
strong base so that pH of the buffer solution is 5?
(a) 1
(b) 2
(c) 10
(d) 1/10
33.
The pH of a 10–10 M NaOH solution is nearest to
(a) 10
(b) 7
(c) 4
(d) – 10
34.
Which of the following is used for preservation of grains?
(a) Potassium permanganate
(b) boric acid
(c) sodium chloride
(d) sodium benzoate
35.
Tincture of iodine is
(a) CHI3 in alcohol (b) I2 in alcohol
(c) I2 in KI
(d) CHI3 in KI
36.
Which among the followings gases is used ti manufacture chloroform?
(a) propane
(b) ether
(c) radone
(d) methane
37.
The specific rate constant of a first order reaction depends on the
(a) concentration of the reactant
(b) concentration of the product
(c) time
(d) temperature
38.
In a reaction involving hydrolysis of an organic chloride
RCl+ H2O ROH + HCl.
(a) molecularity is 2, order of reaction is also 2
(b) molecularity is 2, order of reaction is1
(c) molecularity is 1, order of reaction is2
(d) molecularity is 1, order of reaction is also 1
39.
The rate of reaction between A and B increases by a factor of 100, when the concentration
of A is increased 10 folds, the order of reaction with respect to A is
(a) 10
(b) 1
(c) 4
(d) 2
40.
The specific rate for a reaction is 1.0 × 10–4 mole lit–1 min–1. The order of the reaction is
(a) zero
(b) one
(c) two
(d) three
41.
The rate constant, the activation energy and Arhenius parameter of a chemical reaction at 25°
C are 3.0 × 10–4 s–1, 104.4 kJ mol–1 and 6.0 × 1014 s–1 respectively. The value of the rate
constant at T
is
(a) 2.0 × 1018 s–1
(b) 6.0 × 1014 s–1
(c) inifintiy
(d) 3.6 × 1030 s–1
42.
In a reaction 2A + B A2 B, the reactant A will disappear at
(a) half the rate at that B will decrease
(b) the same rate at that B will decrease
(c) the same rate at that A2B will form
(d) twice the rate at that B will decrease
43.
The rate constant k1of a reacti-onis found to be double that of rate constant k2 of another
reaction.The relationship between corresponding activation energies of the two reactions at
same temperature (E1 and E2) can be represented as
(a) E1 > E2
(b) E1 < E2
(c) E1 = E2
(d) None
44.
In the reaction A + B Products, if B is taken in excess, then it is an example of
(a) second order reaction
(b) zero order reaction
(c) pseudo-unimolecular reaction
(d) first order reaction
45.
Consider the following statement about entropy
1. The entropy is a measure of randomness.
2. Entropy is a function of the state of the system.
3. Entropy is an intensive property.
4. For a reversible cyclic process the integral of entropy will be zero.
(a) 1, 2 and 3 are correct
(b) 1, 2 and 4 are correct
(c) only 4 is correct
(d) 2 and 4 are correct
46.
In acidic medium MnO4– is an oxidising agent.
MnO4– + 8H+ + 5e– Mn2+
If H+ ions concentration is doubled, electrode potential of the half cell
will
(a) increase by 28.46 mV
(b) decrease by 28.46 mV
(c) increase by 14.23 mV
(d) decrease by 142.30 mV
MnO4–, Mn2+ | Pt
47.
In which of the following cells will the emf be independent of the activity of the chloride ions
(a) Zn | ZnCl2 (aq.) | Pt (Cl2)
(b) Zn | ZnCl2 (aq.) || KCl (aq.) | Ag Cl(s) , Ag
(c) Ag, AgCl (s) | KCl (aq.) |Pt (Cl2)
(d) Hg, Hg2Cl2 (s) | KCl ||AgNO3 (aq.) | Ag
48.
When lead storage battery discharges
(a) SO2 is evolved
(b) PbSO4 is consumed
(c) lead is formed
(d) sulphuric acid is consumed
49.
Stronger the oxidising agent, greater is the
(a) reduction potential
(b) ionic behaviour
(c) oxidation potential
(d) none of these
50.
The ionic conductivity of the cation and anion of the uni-univalent salt is 140 and 80
respectively. The molar conductivity of the salt is 160 W–1 cm2 mole–1
(a) mercury cell
(b) Daniel cell
(c) lead storage cell (d) fuel cell
ANSWER KEYS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
(a)
(b)
(c)
(b)
(b)
(a)
(c)
(b,c)
(a)
(d)
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
(d)
(c)
(b)
(c)
(b)
(c)
(b)
(b)
(b)
(a)
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
(c)
(c)
(c)
(c)
(a)
(b)
(b)
(c)
(b)
(b)
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
(c)
(c)
(b)
(d)
(a)
(d)
(d)
(b)
(d)
(a)
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
(b)
(b)
(d)
(c)
(b)
(a)
(c)
(d)
(a)
(d)