WAEC Chemistry Past Questions & Answers - Page 9

The general formula for alkanes is \(C_nH_{2n}+2\). For an alkane with 49 carbon atoms (n = 49), the number of hydrogen atoms can be calculated as follows:

Number of hydrogen atoms (H) = 2n + 2
Number of hydrogen atoms (H) = 2 * 49 + 2
Number of hydrogen atoms (H) = 98 + 2
Number of hydrogen atoms (H) = 100

So, an alkane with 49 carbon atoms contains 100 hydrogen atoms.

Dilute trioxonitrate (V) acid does not produce hydrogen when it reacts with metals because it is a strong oxidizing agent.
Trioxonitrate (V) acid, also known as nitric acid, is a strong oxidizing agent. This means that it can easily oxidize metals, which means that it can remove electrons from metals. When nitric acid oxidizes a metal, it forms salt and water. The salt does not contain hydrogen, so no hydrogen gas is produced

Polymerization is a process in which small molecules combine to form larger molecules. This process is not consistent with the kinetic theory of matter because it does not involve the movement of particles. The particles in a polymer are not moving randomly. They are bonded together in a fixed structure.
Therefore, the property that does not give evidence of the kinetic theory of matter is polymerization.

Among the given elements, W has the lowest ionization energy (\(12.0 KJ mol^{-1} x 10^{-3})\), indicating that it would be more likely to react with chlorine. X has a higher ionization energy \((21.0 KJ mol^{-1} x 10^{-3})\), so it would be less reactive with chlorine compared to W.
Based on ionization energy values, the elements that would react more readily with chlorine are W and X.

The formation of a bond between hydrogen and a highly electronegative atom results in polarity because the electronegative atom will attract the shared pair of electrons more than the hydrogen atom, creating a dipole with a partial negative charge on the electronegative atom and a partial positive charge on the hydrogen atom.