NECO SSCE - Chemistry - 2001

On exposure to hydrogen sulphide, moist lead (II) ethanoate paper turns

Detalhes da Resposta

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?

Detalhes da Resposta

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

Detalhes da Resposta

The position of an element in the Periodic Table is determined by

Detalhes da Resposta

Which element contains the greatest number of moles?

Detalhes da Resposta

The best way to distinguish between Na₂CO₃and NaHCO₂ is by.

Detalhes da Resposta

To test for the presence of chloride ions in ion, correct sequence of reagents to use is

Detalhes da Resposta

Which compound will have the lowest boiling point?

Detalhes da Resposta

Animal charcoal differs from wood charcoal in that it

Detalhes da Resposta

The Kinetic theory can NOT be used to explain

Detalhes da Resposta

The alloy used for welding and plumbing contains

Detalhes da Resposta

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?

Detalhes da Resposta

Which compound can be used as a reducing agent in a reaction?

Detalhes da Resposta

Which metal will dissolve in aqueous sodium hydroxide?

Detalhes da Resposta

Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?

Detalhes da Resposta

Fructose and glucose are

Detalhes da Resposta

How much sodium hydroxide is required to nka 250 cm3 ofa0.1 molar solution? Na=23; 0=16; H=1]

Detalhes da Resposta

The atomic number of iron is 56. The number of unpaired electrons in the Fe3+ ion is

Detalhes da Resposta

The oxidation number of X in \(XO_{4}^{3-}\) is

Detalhes da Resposta

Which compound is a component of baking powder?

Detalhes da Resposta

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]

Detalhes da Resposta

The use of sulphur to vulcanize rubber is mad to make it

Detalhes da Resposta

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.?

Detalhes da Resposta

The high boiling point of hydrogen fluoride can be explained in terms of

Detalhes da Resposta

White is NOT a property of metals?

Detalhes da Resposta

A measure of the degree of disorderliness in a chemical system is known as the

Detalhes da Resposta

Which statement BEST describes the process of oxidation?

Detalhes da Resposta

Detergents are better than soaps for washing in hard water because

Detalhes da Resposta

Which compound is a product of the hydrolysis of the of CH₃COOC₃H₇ with aqueous sodium hydroxide?

Detalhes da Resposta

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.

Detalhes da Resposta

Which method is NOT used to determine rate of a reaction?

Detalhes da Resposta

in any chemical reaction, the total mass of products is always equal to that of the reactants.

This Is statement of the law of:

Detalhes da Resposta

what dose the following equation illustrate? \( ^{238}U_{92} → ^{234}Th_{90} + ^4 He_2 \)

Detalhes da Resposta

The molar mass of a compound X is 56. its empirical formula is CH2. X is

Detalhes da Resposta

NaCl(s) does NOT conduct electricity, but N(aq) does. This is because

Detalhes da Resposta

The green colour solution of an Fe2 salt changes to a brown solution of an Fe3+ salt by

Detalhes da Resposta

The decreasing order of the oxidising power of the halogens is

Detalhes da Resposta

The maximum number of electrons that can occupy the shell having a principal quantum number of 3 is

Detalhes da Resposta

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

Detalhes da Resposta

The Atomic theory model which explains that electrons in an atom revolve round quantized energy levels is attributed to

Detalhes da Resposta

Faraday s first law of electrolysis can be expressed mathematically as

Detalhes da Resposta