Question

A mass of 45.0 grams of aluminium will react with how many grams of zinc chloride?

Answer 1

Hint: Firstly, write the balanced chemical equation of the given reaction and then make use of the concept of stoichiometry for the conversion of grams of aluminium to grams of zinc chloride and this will give the required answer.

Complete answer:
In the lower classes, we have studied the basic topics like balancing a chemical equation and also about the concept of stoichiometry and balancing equations based on it.
We shall see these concepts in detail so that we can approach the correct answer accordingly.
- Balancing of a chemical equation means that the total number of atoms on the reactant side should be equal to the total number of atoms on the reactant side.
- Now, let us write the balanced chemical equation for the above given data and that will be,
\[2Al+3ZnC{{l}_{2}}\to 2AlC{{l}_{3}}+3Zn\]
Here two moles of aluminium react with tree moles of zinc chloride to give two moles of aluminium chloride and three moles of zinc. This is basically a displacement reaction.
Now, let us make use of stoichiometry.
Molar mass of aluminium is 27.99 g/mol.
Molar mass of zinc chloride is 136.29 g/mol.
Therefore, mole ratio of $ZnC{{l}_{2}}$ to $Al$ is 3 : 2
Now, 45g of aluminium will give$45\times \dfrac{1}{27.99}\times \dfrac{3molesZnC{{l}_{2}}}{2mol(Al)}\times \dfrac{136.29g(ZnC{{l}_{2}})}{1mol(ZnC{{l}_{2}})}=328.6g/mol$
Thus, the correct answer will be 45g of aluminium will react with 328.6g of zinc chloride.

Note:
Note that while writing a balanced equation, be thorough with the basic chemical reaction which is taking place by looking into the data given and then by balancing it accordingly followed by checking the stoichiometry. Stoichiometry is the calculation of reactants and products in chemical reactions.