JAMB UTME - Chemistry - 1984

The solubility curves of four substances are shown in the figure above. Which of the four substances would crystallize from a saturated solution cooled from 353K(80oC)to 323K(50C)?

Maelezo ya Majibu

Alkaline hydrolysis of naturally occurring fats and oils yields

Maelezo ya Majibu

Lime - water, which is used in the laboratory for the detection of carbon(iv)oxide is an aqueous solution of

Maelezo ya Majibu

The balanced equation for the reaction of tetraoxosulphate(VI)acid with aluminium hydroxide to give water and aluminium tetraoxosulphate(VI) is

Maelezo ya Majibu

An example of a neutral oxide is

Maelezo ya Majibu

If the cost of electricity required to deposit 1 g of magnesium is ₦5.00, how much would it cost to deposit 10g of aluminium?

Maelezo ya Majibu

For the reaction 2Fe3+ 2I- $\to$ 2Fe2+ + I2, which of the following statements is TRUE?

Maelezo ya Majibu

An element that can exist in two or more different structural forms which possess the same chemical properties is said to exhibit.

Maelezo ya Majibu

Allotropy or allotropism is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of these elements.

The hybridization of the carbon atom in ethyne is

Maelezo ya Majibu

If an excess of a liquid hydrocarbon is poured into a jar of chlorine, and the sealed jar is then exposed for several hours to bring sunlight, all the chlorine gas is consumed. The hydrocarbon is said to have undergone

Maelezo ya Majibu

Alkanes

Maelezo ya Majibu

Which of the following methods may be used to prepare trioxonitrate (V) acid (nitric acid) in the laboratory?

Maelezo ya Majibu

Sodium hydroxide (NaOH) pellets are

Maelezo ya Majibu

Which of the following statements is NOT correct about all four of the acids: HBr, HNO3, H 2CO3 and H2SO4? They

Maelezo ya Majibu

In which of the following reactions does hydrogen peroxide act as a reducing agent?

Maelezo ya Majibu

The ratio of the number of molecules in 2g of hydrogen to that in 16g of oxygen is

Maelezo ya Majibu

Naphthalene when heated melts at 354 K (81 oC). At this temperature the molecules of naphthalene

Maelezo ya Majibu

Use the diagram above to answer this question.

Which of the following structural formula is NOT isomeric with the others?

Maelezo ya Majibu

Water is said to be 'hard' if it

Maelezo ya Majibu

Which of the following statements is NOT true of carbon monoxide?

Maelezo ya Majibu

The I.U.P.A.C name for the compound is

Maelezo ya Majibu

Which of the curves shown in the figure given represents the relationships between the volume(V) and pressure(P) of an ideal gas at constant temperature?

Maelezo ya Majibu

Which of the following statements is INCORRECT?

Maelezo ya Majibu

20 cm 3 of hydrogen gas are sparked with 20cm 3 of oxygen gas in an endimoeter at 373k (100 oC) and 1 atmosphere. The resulting mixture is cooled to 298 K (25 oC) and passed over calcium chloride. The volume of the residual gas is

Maelezo ya Majibu

2H2 + O2 ------2H2O
2V 1V 2V
20cm3 20cm3 -------
20cm3 10cm3 20cm3
Residual gas = 20cm3 - 10cm3 of 02 = 103

Nitrogen can best be obtained from a mixture over oxygen and nitrogen by passing the mixture over

Maelezo ya Majibu

An organic compound with a vapour density 56.5 has the following percentage composition:C =53.1% N = 12.4%, O = 28.3%, H = 6.2%. The molecular formula of the compound is

Relative atomic masses: N = 14, O = 16, C = 12, H = 1 )

Maelezo ya Majibu

A molar solution of caustic soda is prepared by dissolving

Maelezo ya Majibu

For the reaction NH4NO2 $\to$ N2 + 2H2O, calculate the volume of nitrogen that would be produced at S. T. P from 320 g of the dioxonitrate(iii)salt. (Relative atomic masses: N = 14, O = 16, H = 1)

Maelezo ya Majibu

At S. T. P how many litres of hydrogen can be obtained from the reaction of 500 cm3 of 0.5 M H 2SO 4 with excess zinc metal?

(Gram molecular volume of H2 = 22. 4 dm 3)

Maelezo ya Majibu

In the Haber process for the manufacture of ammonia, finely divided iron is used as

Maelezo ya Majibu

3Cl2 + 2NH3 $\to$ N2 + 6HCl. In the above reaction, ammonia acts as

Maelezo ya Majibu

In dilute solution the heat of the reaction NaOH + HCl = NaCl + H2O is - 57.3kJ. Therefore the heat of the reaction 2NaOH + H2SO4 $?$ Na2SO4 + 2H2O is

Maelezo ya Majibu

NaOH + HCl = NaCl + H2O $\Delta$H = -57.3kJ

Heat of reaction of 2NaOH + H2O4

NaSO4 + H2O is

= 57.3 x 2 = -114.6 kJ

The name of the compound above is

Maelezo ya Majibu

Sodium chloride may be obtained from brine by

Maelezo ya Majibu

The function of conc. H2SO4 in the esterification of ethanoic acid with ethanol is to

Maelezo ya Majibu

Which of the following electrodes is used in electrolysis of bauxite (Al2O3) in molten cryolite?

Maelezo ya Majibu

Use the diagram above to answer this question.

Which of the following represents a carboxylic acid?

Maelezo ya Majibu

Which among the elements 1. Carbon 2. Oxygen 3. Copper 4. Bromine 5. Zinc, will NOT react with either water or steam?

Maelezo ya Majibu

A piece of sea shell, when dropped into a dilute solution of hydrochloric acid, produces a colourless, odourless gas which turns clear limewater milky. The sea shell contains

Maelezo ya Majibu

When the kerosene fraction from petrol is heated at high temperature, a lower boiling liquid is obtained. This process is known as

Maelezo ya Majibu

The diagram above (Fig.3) shows the energy profile for the reaction A + B + = C + D From this diagram, it is clear that the reaction is

Maelezo ya Majibu

An aqueous solution of a metal salt, M, gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia. Therefore cartion in M is

Maelezo ya Majibu

Sulphur

Maelezo ya Majibu

From the reactions : ZnO + Na2O $\to$ NaZnO and ZnO + CO2 $\to$ ZnCO3 it may be concluded that zinc oxide is

Maelezo ya Majibu

Which of the following mixtures would result in a solution of pH greater than 7?

Maelezo ya Majibu