NECO SSCE - Chemistry - 2003

At s.t.p, a mole of chlorine occupies 22.4dm³. If the temperature is changed to 35°C and the pressure to 750mHg the of the new volume will be [Cl = 35.5]

Détails de la réponse

Which is NOT a synthetic polymer?

Détails de la réponse

What is the IUPAC name of CH₃CCI=C(CH₃)2?

Détails de la réponse

What is formed when starch is completely hydrolysed?

Détails de la réponse

Chlorine displaces bromine from aqueous potassium bromide because

Détails de la réponse

Which separation technique is routinely applied in the petroleum industry?

Détails de la réponse

What is the number of moles of NaHCO₃in 250cm³ of its solution if the solution contains 8.4 g of NaHCO₃ in 1 dm³ of the solution. [Na = 23, 0 = 16, C = 12, H = 1)

Détails de la réponse

Which metal is extracted from bauxite?

Détails de la réponse

Which metal is a constituent of both bronze and solder?

Détails de la réponse

Which formula is used to indicate the degree of acidity of an acid?

Détails de la réponse

What is the change in the oxidation number of phosphorus in the following reaction?

4P(s) + 5O₂(ag) → 2P₂O₅(s)

Détails de la réponse

Why is tetraoxosulphate(VI) acid NOT used for making carbon dioxide from calcium carbonate? It is

Détails de la réponse

What mass of copper is deposited when 6.5g of granulated zinc reacts with excess copper(II) tetraoxosulphate(VI) solution?

The equation for the reaction is: Zn(s) + \( CuSO_4(aq)→ ZnSO_4(aq)+ Cu(s)\)[CU= 64; Zn=65]

Détails de la réponse

Which statement is NOT true about the composition of starch?

Détails de la réponse

Small amounts of compounds of transition metals are sometimes added to glass during manufacture in order to make the glass

Détails de la réponse

Which element is the most electronegative?

Détails de la réponse

In the reaction 2H₂S(g) + SO₂(g) → 2H₂SO(I)+3S(s)SO₂is acting as _agent

Détails de la réponse

A calcium atom and a calcium ion have the same

Détails de la réponse

Which compound will give propane when it Is dehy drated by an excess of hot, concentrated tetraoxosvlphate(VI) acid?

Détails de la réponse

The pH of water is 7.

What is the pH of orange juice?

Détails de la réponse

The boiling point of water is higher than the boiling point of ethanol because

Détails de la réponse

Which metal bromide is widely used in photography?

Détails de la réponse

Chlorine is used in water purification because it

Détails de la réponse

Ethene decolourises acidified potassium tetraoxomanganate(VII) solution. Which gas will decolourise bromine water?

Détails de la réponse

An organic compound gave the following results on analysis: C = 29.3% ; H = 5.7%; Br = 65%.
What is the empirical formula of the compound? [C = 12, H = 1, Br=80]

Détails de la réponse

The number of hydrogen ions in 1.0dm6.00x10³ of a 0.25 mole dm6.00x10^-3 tetraoxosulphate(Vl) acid solution is
[Avogadro constant = 6.0 x 1 0]

Détails de la réponse

Which method is used for the purification of copper from its ore?

Détails de la réponse

How many Faradays of electricity are required to liberate 9g of aluminium? [Al = 27]

Détails de la réponse

Why does the treatment of cotton fabrics with dilute acids weaken the materials?

Détails de la réponse

Which hydrocarbon does NOT exhibit structural isomerism?

Détails de la réponse

The reaction C₂H₆ → C₂H + H₂ is known as

Détails de la réponse

What change will occur during the electrolysis of brine using carbon electrodes?

Détails de la réponse

B is an isotope of the element \(^{238} _{92}Ur\). The isotope B has

Détails de la réponse

What mass of silver is deposited when a current of 2.6 A is passed through a solution of a silver salt for 40 minutes? [Ag= 108 ; F=96500C]

Détails de la réponse

What is the concentration (in mol dm³) of a solution containing 28 g of potassium hydroxide per 100 cm³ of solution? (K=39; H=1; 0=16)

Détails de la réponse

What change will occur to the equilibrium mixture
\( 2CrO^{2-}_4(aq) + 2H^+(aq) ⇔ Cr_2O^{2-}_7(aq) + H_2O(l) \) when excess sodium hydrogen solution is added?

Détails de la réponse

An atom of element X has an electronic configuration of \( 1s^22p^33s^23p^2. \) In which group of the periodic table is X?

Détails de la réponse

Naturally occurring lithium consists of 90% \( ^7_3Li \text{ and 10% } ^6_3 Li. \) What is the relative atomic mass of lithium?

Détails de la réponse