Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
The following statements are correct except
energy is released when liquids change to solids.
carbon atoms in gaseous methane are further apart than those in solid diamond.
there is large decrease in the volume of a solid metal when pressure is applied to it.
particles move faster in the gaseous state than in the liquid state.
Correct answer is C
In general, solids are relatively incompressible compared to liquids and gases. When pressure is applied to a solid, there is typically only a small change in volume. Solids have tightly packed particles with strong intermolecular forces, making them less responsive to changes in pressure. Liquids and gases, on the other hand, can undergo larger volume changes in response to pressure.
40
120
65
30
Correct answer is D
Molar mass of C2H4O2,= (12 × 2) + (1 × 4) + (16 × 2)= 60 g/mol
Vapour density = RMM/2
=60/2=30
Which of the following is a common laboratory indicator for bases?
Methyl orange
Phenolphthalein
Bromothymol blue
Litmus
Correct answer is B
Phenolphthalein is a common laboratory indicator used to detect the presence of bases in a solution. In its basic form (pH > 8.3), it turns pink or purple, indicating the presence of a base.
What is the maximum number of electrons that can occupy the second energy level (n=2)?
2 electrons
18 electrons
8 electrons
32 electrons
Correct answer is C
The correct answer is (b). The second energy level (n=2) can hold a maximum of 8 electrons. It consists of two subshells, 2s and 2p, which can hold 2 and 6 electrons, respectively.
Which of the following statements is true for strong electrolytes?
They do not conduct electricity in the molten state
They completely dissociate into ions in solution
They are non-polar substances
They partially dissociate into ions in solution
Correct answer is B
They completely dissociate into ions in solution. Strong electrolytes are substances that fully dissociate into ions when dissolved in water or melted. As a result, they produce a high concentration of ions in the solution, allowing for efficient electrical conductivity.