DELSU Chemistry 2018/2019 Past Questions

Practice each question, then open it to see the full details.

In an attempt to remove sugar from a beaker containing a quantity of sand and sugar, 2m ammonium. Chloride solution was accidentally added instead of water. Which of the following methods could be used to remove the ammonium chloride from the mixture?

A.fractional distillation
B.crystallization
C.filtration followed by evaporation
D.evaporation followed by sublimation

Which of the following process does NOT lead to a chemical change?

A.stiring iron in sulphur (vi) acid
B.stirring sodium carbonate in water
C.stirring glucose in concentrated sulphur (vi) acid
D.mixing sulphur (vi) acid with potassium carbonate

The mass number of an atom is

A.the number of electrons in the atoms
B.the number of protons in the nucleus of the atom
C.the number of neutrons in the nucleus of the atom
D.the sum of numbers of protons and neutrons in the nucleus of the atom

The reaction between sulphur (iv) oxide and oxygen is represented by the equilibrium reaction : 2SO₂(g) O₂⇆ Δ 196kJ.
What factor would influence increased
production of SO₃(g)?

A.Addition of a suitable catalyst
B.increase in the temperature of the reaction.
C.decrease in the temperature of the reaction
D.decrease in the concentration of SO₂

The electronic configuration of elements X and Y are x = 2,8, 6 ; Y = 2, 8.7. The bond in the compound formed by x and y is expected to be

A.ionic
B.covalent
C.dative covalent
D.metallic

A gas occupies 30.0dm³ at S.T.P. What volume would it occupy at 91°C and 380mmHg?

A.20.0dm³
B.40.0dm³
C.60.0dm³
D.80.0dm³