Firstly the limiting reactant should be identified. Limiting reactant is the reactant that is in limited supply, the amount of product formed depends on the moles present of the limiting reactant.
the stoichiometry of x to y = 1:2
1 mole of x reacts with 2 moles of y
if x is the limiting reactant, there are 3 moles of x, then 6 moles of y should react, however there are only 4 moles of y. Therefore y is the limiting reactant and x is in excess.
4 moles of y reacts with 2 moles of x
since there are 3 moles of x initially and only 2 moles are used up, excess amount of x is 1 mol thats in excess.
Answer: 5.844 grams of NaCl needed to make solution.
Explanation:
Answer: The percentage by mass of sulphur in
is 9.36%
Explanation:
Mass percent of an element is the ratio of mass of that element by the total mass expressed in terms of percentage.

Given: mass of sulphur = 32 g/mol
mass of
= 342 g/mol
Putting in the values we get:

The percentage by mass of sulphur in
is 9.36%
I believe the correct answer from the choices listed above is the last option. The term that would best describe the <span>role of hydrogen gas in the formation of a water molecule would be a reactant. Water has a formula of H2O where it contains water so it should be that hydrogen is a reactant. </span>