The chemical equation given below represents the chemical reaction between lithium (li) and sulfur (s). in the equation, why is the number 2 present in front of lithium on the reactants side of the equation?
a. to show the number of lithium atoms involved in the reaction
b. to show the number of electrons gained by lithium in the reaction
c. to show the atomic number of lithium in the periodic table
d. to show the number of electrons lost by lithium in the reaction

Option (A) is the correct answer.

Explanation:

The given chemical reaction equation is as follows.

As the number of atoms on both reactant and product side are the same. Hence, it is a balanced chemical reaction equation.

Here, number 2 before lithium atom represents that two atoms of lithium are taking part in the reaction. As there is no coefficient or number placed before the sulfur atom this means that only one atom of sulfur is reacting in the reaction.

Thus, we can conclude that the number 2 present in front of lithium on the reactants side of the equation shows the number of lithium atoms involved in the reaction.

answer; i believe that the correct answer is (a) potassium(k)

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%