Aluminium hydroxide is used in the dyeing industry as a
Respondre
(D)
mordant
5
The tincture of iodine means iodine dissolved in
Respondre
(A)
ethanol
6
Temporary hard water is formed when rain water containing dissolved carbon(IV) oxide flows over deposits of
Respondre
(A)
CaCO3
7
The acid anhydride that will produce weak acid in water is
Respondre
(D)
CO2
8
The process that occurs when two equivalent forms of a compound are in equilibrium is
Respondre
(B)
Resonance
9
In the laboratory preparation of ethyl ethanoate, the water present in the mixture is removed using ?
Respondre
(A)
Anhydrous CaCl2
10
The constituent of air necessary in the rusting process are
Respondre
(A)
O2 and H2O
11
For a general equation of the nature xP + yQ → mR + nS, the expression for the equilibrium constant is
Respondre
(C)
\(\frac{[R]^m [S]^n}{[P]^x [Q]^y}\)
12
A given mass of gas occupies 2dm3 at 300k. At what temperature will its volume be doubled, keeping the pressure constant?
Respondre
(D)
600k
13
The oxidation number of iodine in KIO3 is
Respondre
(C)
+5
14
An isomer of C5H12 is
Respondre
(C)
2–methyl butane
15
When few drops of concentrated trioxonitrate(V) acid is added to an unknown sample and wanned an intense yellow colouration is observed. The likely functional group present in the sample is
Respondre
(A)
NH2RCHCOOH
16
A sample of orange juice is found to have a PH of 3.80. What is the concentration of the hydroxide ion in the juice?
Respondre
(B)
6.3 \(\times\) 10-11
17
Incomplete oxidation of ethanol yields
Respondre
(D)
CH3CHO
18
The salt formed from a weak acid and a strong base hydrolyzes in water to form
Respondre
(D)
an alkaline solution
19
The ideal gas laws and equations are true for all gases at
The mass of silver deposited when a current of 10A is passed through a solution of silver salt for 4830s is – (Ag = 108 F = 96500(mol-1)
Respondre
(A)
54.0g
24
Tin is unaffected by air at ordinary temperature due to its?
Respondre
(B)
Weak electropositive character
25
Calculate the amount in moles of silver deposited when 9650C of electricty is passed through a solution of silver salt [= 96500 Cmol-1]
Respondre
(D)
0.10
26
The reaction of halogens with alkanes in the presence of sunlight is an example of
Respondre
(D)
substitution reaction
27
The enzyme used in the hydrolysis of starch to dextrin and maltose is?
Respondre
(B)
amylase
28
The alkyl group is represented by the general formula
Respondre
(C)
CnH2n + 1
29
Cu\(_2\)S(g) + O\(_2\)(g) → 2Cu + SO\(_2\)(g)
What is the change in the oxidation number of copper in the reaction?
Respondre
(C)
+ 1 to 0
30
In the diagram above. X is
Respondre
(B)
SO2
31
The diagram above. Y is
Respondre
(D)
Concentrated H2SO4
32
Calculate the mass of copper deposited when a current of 0.5 ampere was passed through a solution of copper(II) chloride for 45 minutes in an electrolytic cell. [Cu = 64, F = 96500Cmol-1]
Respondre
(D)
0.448g
33
The IUPAC nomenclature of the structure above is
Respondre
(B)
2-methylbut-1-ene
34
The reddish–brown rust on iron roofing sheets consists of
Respondre
(C)
Fe2O3.XH2O
35
The densities of two gases, X and Y are 0.5gdm-3 and 2.0gdm-3 respectively. What is the rate of diffusion of X relative to Y?
Respondre
(C)
2.0
36
The carbon atoms on ethane are
Respondre
(B)
sp3 hybridized
37
According to Charle's law, the volume of a gas becomes zero at
Respondre
(B)
−273°c
38
An oxide XO2 has a vapour density of 32. What is the atomic mass of X?
Respondre
(B)
32
39
The gas that can be collected by downward displacement of air is
Respondre
(D)
ammonia
40
In the laboratory preparation of trioxonitrate (V) acid the nitrogen(iv) oxide formed as a by-product is removed by
Respondre
(D)
bubbling air through the acid solution
41
A particle that contains 9 protons, 10 neutrons and 10 electrons is
Respondre
(D)
negative ion
42
Ethene is prepared industrially by
Respondre
(D)
Cracking
43
Calculate the amount in moles of a gas which occupies 10.5 dm3 at 6 atm and 30oC [R = 0.082 atm dm3 K-1 mol-1]
Respondre
(A)
2.536
44
If 100cm3 of oxygen pass through a porous plug is 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is? [O = 16, H = 1]
Respondre
(B)
12.5s
45
Due to the high reactivity of sodium, it is usually stored under
