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Pregunta 1 Informe
The use of sulphur to vulcanize rubber is mad to make it
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Pregunta 5 Informe
The maximum number of electrons that can occupy the shell having a principal quantum number of 3 is
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Pregunta 6 Informe
The molar mass of a compound X is 56. its empirical formula is CH2. X is
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Pregunta 8 Informe
what dose the following equation illustrate? \( ^{238}U_{92} → ^{234}Th_{90} + ^4 He_2 \)
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Pregunta 9 Informe
The best way to distinguish between Na2CO3and NaHCO2 is by.
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Pregunta 10 Informe
if an element X with atomic number 13 combines with an element Y whose atomic number is 8 the most likely formula of the compound formed between X and Y is?
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Pregunta 12 Informe
How much sodium hydroxide is required to nka 250 cm3 ofa0.1 molar solution? Na=23; 0=16; H=1]
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Pregunta 13 Informe
20 cm3 of 0.09 mol dm3 solution of tetraoxosuiphate (Vi) acid requires 30cm3 of sodium hydroxide solution for complete neutralization. The molar concentration of sodium hydroxide is [H = 1; S = 32; 0 = 16; Na = 23]
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Pregunta 15 Informe
When an electric current is passed through a solution containing dilute tetraoxosulphate (Vi) acid, 190 cm3 of hydrogen gas is evolved. if the measurements were made at 26°C and 736 mmHg, what is the volume of hydrogen at s.t.p.?
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Pregunta 16 Informe
Detergents are better than soaps for washing in hard water because
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Pregunta 17 Informe
Which of the following is TRUE of a catalyst? I. it alters the activation energy of a reaction
II. it is effective in a reaction but cannot initiate a reaction
III, it affects the equilibrium of a reversible reaction
IV. it affects the overall reaction
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Pregunta 18 Informe
The high boiling point of hydrogen fluoride can be explained in terms of
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Pregunta 19 Informe
Which compound can be used as a reducing agent in a reaction?
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Pregunta 20 Informe
The position of an element in the Periodic Table is determined by
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Pregunta 21 Informe
A measure of the degree of disorderliness in a chemical system is known as the
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Pregunta 22 Informe
Which compound is a product of the hydrolysis of the of CH3COOC3H7 with aqueous sodium hydroxide?
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Pregunta 23 Informe
Which method is NOT used to determine rate of a reaction?
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Pregunta 24 Informe
What is the ratio of the rate of diffusion of carbon(IV) oxide to that of propane, under the same conditions? [H = 1; C= 12; 0= 161
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Pregunta 25 Informe
in any chemical reaction, the total mass of products is always equal to that of the reactants.
This Is statement of the law of:
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Pregunta 28 Informe
Which statement BEST describes the process of oxidation?
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Pregunta 29 Informe
The green colour solution of an Fe2 salt changes to a brown solution of an Fe3+ salt by
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Pregunta 32 Informe
A gas X diffuse through porous partition at the rate of 3 cm3 per second. Under the same condition hydrogen diffused at the rate of 15 cm3 per second.
What is the 42. relative molecular mass of X.
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Pregunta 33 Informe
The decreasing order of the oxidising power of the halogens is
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Pregunta 34 Informe
The atomic number of iron is 56. The number of unpaired electrons in the Fe3+ ion is
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Pregunta 35 Informe
Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?
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Pregunta 36 Informe
NaCl(s) does NOT conduct electricity, but N(aq) does. This is because
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Pregunta 37 Informe
The Atomic theory model which explains that electrons in an atom revolve round quantized energy levels is attributed to
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Pregunta 38 Informe
Faraday s first law of electrolysis can be expressed mathematically as
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Pregunta 39 Informe
An experiment to test the conductance of 0,1 M solutions of the substances listed below was perform.
I ammonia
II ammonium chloride
III ethanoic acid
IV sodium ethanoate
Which pair of substances show the least conductance?
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Pregunta 40 Informe
On exposure to hydrogen sulphide, moist lead (II) ethanoate paper turns
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Pregunta 41 Informe
To test for the presence of chloride ions in ion, correct sequence of reagents to use is
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