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Vraag 3 Verslag
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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Vraag 5 Verslag
The high boiling point of hydrogen fluoride can be explained in terms of
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Vraag 7 Verslag
Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?
Vraag 10 Verslag
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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Vraag 11 Verslag
The molar mass of a compound X is 56. its empirical formula is CH2. X is
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Vraag 12 Verslag
The Atomic theory model which explains that electrons in an atom revolve round quantized energy levels is attributed to
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Vraag 13 Verslag
The maximum number of electrons that can occupy the shell having a principal quantum number of 3 is
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Vraag 14 Verslag
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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Vraag 15 Verslag
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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Vraag 18 Verslag
Faraday s first law of electrolysis can be expressed mathematically as
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Vraag 20 Verslag
To test for the presence of chloride ions in ion, correct sequence of reagents to use is
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Vraag 21 Verslag
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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Vraag 22 Verslag
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
Vraag 25 Verslag
Which compound is a product of the hydrolysis of the of CH3COOC3H7 with aqueous sodium hydroxide?
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Vraag 28 Verslag
NaCl(s) does NOT conduct electricity, but N(aq) does. This is because
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Vraag 29 Verslag
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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Vraag 30 Verslag
A measure of the degree of disorderliness in a chemical system is known as the
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Vraag 32 Verslag
The atomic number of iron is 56. The number of unpaired electrons in the Fe3+ ion is
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Vraag 34 Verslag
How much sodium hydroxide is required to nka 250 cm3 ofa0.1 molar solution? Na=23; 0=16; H=1]
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Vraag 35 Verslag
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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Vraag 37 Verslag
what dose the following equation illustrate? \( ^{238}U_{92} → ^{234}Th_{90} + ^4 He_2 \)
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Vraag 39 Verslag
The green colour solution of an Fe2 salt changes to a brown solution of an Fe3+ salt by
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Vraag 41 Verslag
On exposure to hydrogen sulphide, moist lead (II) ethanoate paper turns
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