An organic compound X has the following properties: I. It is not miscible with water. ll. lt has boiling point of 77oC lll. lt has a sweet odour lV. lt is insoluble in sodium hydrogen carbonate solution . V lt does not decolourize bromine water X is therefore
תְשׁוּבָה
(D)
ethyl ethanoate
2
Which are the correct IUPAC names for H-CO\(_2\)CH\(_3\) and CH \(\equiv\) CH
תְשׁוּבָה
(D)
Methyl methanoate and ethyne
3
Which of the following substances are all made by the process of polymerization?
תְשׁוּבָה
(C)
Nylon and artificial rubber
4
The reaction of zinc with copper (ll) ions in aqueous solution can be represented as follows: Cu 2+(aq) +Zn (s) → Cu(s) + Zn 2+(aq).Which of the following is the most complete description of this reaction?
תְשׁוּבָה
(E)
copper(ll) ions are being reduced and zinc oxidized
5
The oxidation state of manganese in potassium permanganate is
תְשׁוּבָה
(A)
+7
6
When carbondioxide is bubbled into limewater a white precipitate is formed. If the passage of the gas is continued, the precipitate disappears. The reason for this is
תְשׁוּבָה
(C)
calcium carbonate is formed which on reaction with further carbondioxide forms solube calcium hydrogen carbonate
7
Methanoic acid mixes with water in all proportions and has about the same boiling point as water which of the following methods would you adopt to obtain pure water from a mixture of stand, water and methanoic acid?
תְשׁוּבָה
(E)
neutralization with sodium hydroxide followed by filtration
8
Which of the following statements applies during the electrolysis of sodium hydroxide solution using platinum electrodes?
תְשׁוּבָה
(B)
Hydrogen ions are discharged at the cathode
9
Which of the following statements is true? When the potassium atom forms its ion
תְשׁוּבָה
(C)
it achieves electronic configuration of orgon
10
Which of the following contains two amphoteric oxides?
תְשׁוּבָה
(B)
Aluminium oxide, Calcium oxide, Zinc oxide
11
Helium atoms are chemically unreactive because
תְשׁוּבָה
(D)
the outer electron shell is completely filled
12
\(50cm^{3}\) of hydrogen are sparked with \(20cm^{3}\) of oxygen at \(100°C\) and \(1atm\) . The total volume of the residual gases in
תְשׁוּבָה
(A)
50 cm3
13
How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80)
תְשׁוּבָה
(C)
8. 1g
14
When ammonium, potassium and calcium carbonates are each separately heated
תְשׁוּבָה
(E)
ammonium carbonate will decompose to give carbondioxide, water and ammonia
15
If chlorine gas is bubbled into water and then this yellowish-green coloured solution is exposed to bright sunlight for a while
תְשׁוּבָה
(E)
the solution will give out oxygen gas leaving behind aqueous hydrochloric acid
16
12 g of solid protassium chlorate (KCIO) were added to 40 g of water and heated to dissolve all the solid. As the solution cools, crystals of potassium chlorate at 66 oC. The solubility of potassium chlorate at 66 oC is therefore?
תְשׁוּבָה
(E)
30
17
In the electrolysis of dilute sulphuric acid using platinum electrodes, the products obtained at the anode and cathode are:
Anode Cathode
תְשׁוּבָה
(C)
Oxygen Hydrogen
18
The empirical formula of an oxide of nitrogen containing 30.4 per cent of nitrogen is (N=14.0,O=16.0)
תְשׁוּבָה
(C)
NO2
19
When a piece of charcoal enclosed in a cylinder containing air is ignited
תְשׁוּבָה
(D)
the relative amount of carbondioxide present is increased
20
Indicate which of the following statements is not true as we move from left to right along the periodic Table:
תְשׁוּבָה
(C)
electropositive character of elements increases
21
0.1 Faraday of electricity was passed through a solution of copper (ll) sulphate. The maximum weight of copper deposited on the cathode would be [Cu = 64]
תְשׁוּבָה
(E)
3.2g
22
Which one of these compounds will NOT give an oxygen gas on heating?
תְשׁוּבָה
(E)
Ammonium nitrate
23
In the extraction of aluminum from purified bauxite by electrolysis, cryolite is used because
תְשׁוּבָה
(B)
it makes bauxite melt at a lower temperature
24
In the redox reaction\( 2Fe^{2+} + CI_2 → 2Fe^{3+} + 2Cl^-\)
תְשׁוּבָה
(B)
Cl2 is reduced because its oxidation number has decreased
25
An anhydride is?
תְשׁוּבָה
(C)
an oxide whose solution in water has a PH less than 7
26
In which of the following reactions is sulphur dioxide acting as an oxidizing agent?
תְשׁוּבָה
(D)
SO2 + 2H2S → 3S + 2H2O
27
Calcium hydroxide and ammonium chloride when heated together will give an important product. This compound may be obtained dry by
תְשׁוּבָה
(C)
passing it through calcium oxide
28
Starch can be converted to ethyl alcohol by
תְשׁוּבָה
(B)
fermentation
29
The reaction between hydrogen and iodine may be represented by the equation H2(g)+ I2(g) → 2HI(g), and is exothermic. Therefore
תְשׁוּבָה
(D)
a decrease in temperature will favour the forward reaction
30
Weighed salts Y and Z were left exposed in the laboratory overnight. In the morning Y had gained weight, and Z had become liquid. What conclusion could be drawn about the nature of the two salts?
תְשׁוּבָה
(D)
Y and Z are hygroscopic
31
In the manufacture of iron in the blast furnace, iron (lll) oxide is mixed with coke and limestone, and different reactions occur in the process. Which of the following statements is true with respect to these reactions?
תְשׁוּבָה
(E)
the calcium carbonate decomposes to give calcium oxide, which then forms calcium silicate with the earthly impurity
32
Which of the following statements is true?
תְשׁוּבָה
(D)
a increase in the pressure of a gas is proportional to the decrease in volume at constant temperature
33
the vapour density of a gas may be defined as
תְשׁוּבָה
(B)
the mass of a unit volume of the gas compared to an equal volume of hydrogen
34
The reaction 3C(s) + 2Fe2O3(s) = 4Fe(s) + 3CO2(g): \(\Delta\)H =46.0 kJ is
תְשׁוּבָה
(D)
endothermic
35
The solution of a sample in a tube will be identified as a chloride if it gives
תְשׁוּבָה
(C)
a white precipitate when acidified with dilute HNO3 and then AgNO3 solution added
36
Hydrogenation may be effected by
תְשׁוּבָה
(C)
the addition of hydrogen to an alkyne
37
Two metallic ions associated with hard water are
תְשׁוּבָה
(C)
calcium and magnesium
38
Bronze is an alloy of
תְשׁוּבָה
(E)
tin and copper
39
Phosphorus burns in oxygen according to the equation P\(_4\) + 5 0\(_2\) → P\(_4\)O\(_{10}\). How many litres of oxygen will be required at S.T.P for complete oxidation of 12.4g of phosphorus? [P = 31,O = 16 and molar volume of a gas at S.T.P = 22.4 litres]
תְשׁוּבָה
(B)
11. 20
40
On heating anhydrous iron (ll) sulphate, in addition to producing iron (iii) oxide, which of the following is produced?
תְשׁוּבָה
(C)
SO2 (g) + SO3(g)
41
One of the following techniques can be used to show that chlorophyll pigment is a mixture of chemical compounds and not a single coloured compound
תְשׁוּבָה
(E)
chromatography
42
A gas occupies a volume of 30.0 dm\(^3\) at S.T.P. What volume would it occupy at 91\(^0\)C and 380 mm Hg?
תְשׁוּבָה
(D)
80. 0dm3
43
When excess ethanol is heated to 145 oC in the presence of concentrated sulphuric acid, the product is
תְשׁוּבָה
(A)
diethyl ether
44
Which of the following raw materials would be required from the smelting of iron ore in a blast furnace?
תְשׁוּבָה
(A)
CaCO 3
45
A piece of metal (M) is dissolved in nitric acid and the resulting solution is treated with a small quantity of sodium hydroxide to produce a white precipitate (B) which redissolves on the addition of excess alkali. The precipitate (B)when ignited in a crucible produces the oxide of the metal(m). The METAL M is
