The balanced chemical reaction for the substances given would be as follows:
Zn + 2HCl = ZnCl2 + H2
We are given the amounts of the reactants used in the reaction. We use these amounts to determine which is the limiting and excess reactant. We do as follows:
10 g Zn (1 mol / 65.38 g) = 0.1530 mol
10 g HCl (1 mol / 36.46 g) = 0.2743 mol
From the the stoichiometric ratio which is 1 is to 2, the limiting reactant would be hydrochloric acid and the excess would be zinc metal.
Mass of zinc that remains = 0.1530 - (0.2743 / 2) = 0.0159 g Zn
Answer: 3.5 moles
Explanation:
Based on Avogadro's law:
1 mole of any substance has 6.02 x 10^23 molecules
So, 1 mole of SiO4 = 6.02 x 10^23 molecules
Zmoles of SiO4 = 2.1 x 10^{24} molecules
To get the value of Z, cross multiply:
(2.1 x 10^{24} molecules x 1mole) = (6.02 x 10^23 molecules x Z moles)
2.1 x 10^{24} molecules = (6.02 x 10^23 x Z)
Z = (2.1 x 10^{24}) ➗ (6.02 x 10^23)
Z = 3.5 moles
Thus, there are 3.5 moles of SiO4.
The reaction uses B) 9.0 g Br₂.
iron + bromine ⟶ product
2.0 g + <em>x</em> g ⟶ 11.0 g
According to the <em>Law of Conservation of Mass</em>, the total mass of the reactants must equal the total mass of the products.
∴2.0 + <em>x</em> = 11.0
<em>x</em> = 11.0 – 2.0 = 9.0
The reaction uses 9.0 g Br₂.
From what I can recall, I believe the answer is pantothenic acid; acyl transfer. I'm a bio major, hope I helped. :)
