The molar ratio of carbon to hydrogen of a volatile liquid compound is 1: 2. 0. 12 g of the liquid on evaporation at s.t.p. gave 32 cm3 of vapour. The molecular formula of the liquid is[G.M.V =22.4 dm 3, C = 12, H = 1]
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1989
Which of the following would support the conclusion that a solid sample is a mixture?
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1989
Elements X and Y have electronic configurations 1s22s22p6 and 1s22s22p63s23p1 respectively. When they combine, the formula of the compound formed is
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1989
The atomic radius of Li, Na and K are 1: 33A, 1. 54A and 1. 96A res pectively. Which of the following explaqins this gradation in atomic radius?
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1989
What is the partial pressure of hydrogen gas collected over water at standard atmospheric pressure and 25oC if the saturation vapour pressure of water at saturation vapour pressure of water is 23 mm Hg at that temperatur…
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1989
The minimum volume of oxygen required for the complete combustion of a mixture of 10cm 3 of CO and 15 cm 3 of H 2 is
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1989
20.00 cm 3 of a solution containing 0.53 g of anhydrous Na2CO3 in 100 cm3 requires 25.00 cm3 of H2SO4 for complete neutralisation. The concentration of the acid solution in moles per dm is [H =1, C = 12, O = 16, Na =23,…
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1989
Calcium hydroxide is added in the treatment of town water supply to
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1989
The gaseous pollutant sulphur (IV)oxide is most likely to be detected in fairly reasonable quantities in the area around a plant for the
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1989
How many valence electrons are contained in the element represented 3115P?
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1989
Four elements P,Q, R and S have atomic numbers of 4, 10, 12 and 14 respectively . Which of these electrons is a noble gas?
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1989
The atomic number of caesium is 55 and its atomic mass is 133. The nucleus of caesium atom therefore contains
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1989
An acid and its conjugate base
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1989
The substance ZnO dissolves in sodium hydroxide solution and mineral acid solution to give soluble products in each case. ZnO is therefore referred to as
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1989
A solution of calcium bromide contains 20 g dm 3 What is the molarity of the solution with respect to calcium bromide and bromide ions? [Ca = 40, Br = 80]
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1989
Using 50 cm 3 of 1 M potassium hydroxide and 100cm 3 of 1 M tetraoxosulphate (VI) acid, calculate the respective volumes in cm 3 of base and acid that would be required to produce the maximum amount of potassium tetraoxo…
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1989
A hydrated salt of formula MSO4.xH2 O CONTAINS 45.3% by mass of water of crystalisation. Calculate the value of x [M = 56, S = 32, O = 16, H = 1 ]
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1989
Which of the following represents the balanced equation for the reaction of copper with concentrated trioxonitrate (V) acid?
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1989
The combustion of ethene, C 2H 4, is given by the equation C 2H 4 + 30 2 → 2CO2 + 2H2 O; ∆H = - 1428 KJ. If the molar heats of formation of water and carbon (IV) oxide are - 286 kJ and - 396 kJ respectively, calculate th…
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1989
An element, Z froms an anion whose formula is [Z(CN)6]y. If Z has an oxidation number of +2, what is the value of y?