Kf for water is 1.86K kg mol–1. If your automobile radiator holds 1.0 kg of water, how many grams of
ethylene glycol (C2H6O2) must you add to get the freezing point of the solution lowered to –2.8oC ?
คำตอบ
(B)
93 g
2
The density of a solution prepared by dissolving 120 g of urea (mol. Mass = 60 u ) in 1000g of water is
1.15 g/mL. The molarity of this solution is :
คำตอบ
(D)
2.05 M
3
2–Hexyne gives trans–2–Hexene on treatment with :
คำตอบ
(B)
Li/NH3
4
Which branched chain isomer of the hydrocarbon with molecular mass 72u gives only one isomer of
mono substituted alkyl halide ?
คำตอบ
(B)
Neopentane
5
The equilibrium constant (KC) for the reaction N2(g) + O2(g) $$\to$$ 2NO(g) at temperature T is 4 $$\times$$ 10–4. The value of KC for the reaction, NO(g) $$\to$$ 1/2N2(g) + 1/2O2(g) at the same temperature is :
คำตอบ
(D)
50.0
6
The pH of a 0.1 molar solution of the acid HQ is 3. The value of the ionization constant, Ka of this acid is :
คำตอบ
(C)
1 $$\times$$ 10–5
7
The incorrect expression among the following is :
คำตอบ
(C)
In $$K\, = {{\Delta {H^o} - T\Delta {S^o}} \over {RT}}$$
8
The standard reduction potentials for Zn2+/ Zn, Ni2+/ Ni, and Fe2+/ Fe are –0.76, –0.23 and –0.44 V respectively. The reaction
X + Y2+ $$\to$$ X2+ + Y will be spontaneous when :
คำตอบ
(D)
X = Zn, Y = Ni
9
Which one of the following statements is correct ?
คำตอบ
(C)
All amino acids except glycine are optically active
10
In the given transformation, which of the following is the most appropriate reagent ?
คำตอบ
(A)
$$N{H_2}N{H_2},\mathop {OH}\limits^\Theta $$
11
Which of the following compounds can be detected by Molisch’s test ?
คำตอบ
(B)
Sugars
12
Iodoform can be prepared from all except :
คำตอบ
(D)
Isobutyl alcohol
13
What is DDT among the following?
คำตอบ
(D)
Non–biodegradable pollutant
14
How many chiral compounds are possible on monochlorination of 2–methyl butane ?
คำตอบ
(B)
2
15
Which among the following will be named as dibromidobis (ethylene diamine) chromium(III) bromide?
คำตอบ
(B)
[Cr (en)2 Br2 ] Br
16
Iron exhibits + 2 and +3 oxidation states. Which of the following statements about iron is incorrect?
คำตอบ
(D)
Ferrous compounds are more easily hydrolysed than the corresponding ferric compounds.
17
The molecule having smallest bond angle is :
คำตอบ
(C)
SbCl3
18
For a first order reaction, (A) $$\to$$ products, the concentration of A changes from 0.1 M to 0.025 M in 40
minutes. The rate of reaction when the concentration of A is 0.01 M is :
คำตอบ
(B)
3.47 x 10–4 M/min
19
In which of the following pairs the two species are not isostructural ?
คำตอบ
(C)
PF5 and BrF5
20
Ortho–Nitrophenol is less soluble in water than p– and m– Nitrophenols because :
คำตอบ
(B)
o–Nitrophenol shows Intramolecular H–bonding
21
The increasing order of the ionic radii of the given isoelectronic species is :
คำตอบ
(C)
Ca2+ , K+ , Cl– , S2–
22
The electrons identified by quantum numbers n and l :
(a) n = 4, $$l$$ = 1
(b) n = 4, $$ l$$ = 0
(c) n = 3, $$l$$ = 2
(d) n = 3, $$l$$ = 1
Can be placed in order of increasing energy as :
