Answer:
2Al + 3ZnCl₂ → 3Zn + 2AlCl₃
Explanation:
Chemical equation:
Al + ZnCl₂ → Zn + AlCl₃
Balanced Chemical equation:
2Al + 3ZnCl₂ → 3Zn + 2AlCl₃
This is the example of single displacement reaction. Al displace the zinc and form aluminium chloride and zinc metal.
There are two Al three zinc and six chlorine atoms on both side of equation so it is correctly balanced.
Thus it completely follow the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
We have Kc = 4.2 x 10^-2 (given but missing in the question)
and When the balanced equation for this reaction is:
PCl5(g) ↔ PCl3(g) + Cl2(g)
so, according to the Kc formula:
Kc = the concentration of products / the concentration of the reactants
so, to get the concentration of the reactants in equilibrium, the concentration of the products / the concentration of the reactants should equal the Kc value which is given in the question (missing in your question).
So by substitution in Kc formula:
Kc = [PCl3]*[Cl2] / [PCl5]
4.2 x 10^-2 = 0.18 * 0.25 /[PCl5]
∴[PCl5] = 0.18*0.25 / 4.2x10^-2 = 1.07
So the concentration of the reactants in equilibrim = 1.07
Answer= C) CN contains a covalent bond.