78 g of potassium (K) react with 71 g of chlorine (Cl) to produce potassium chloride. According to the Law of Conservation of Mass, what is the mass of the product (2KCl)? (1 point) Responses 4 g 4 g 2 g 2 g 156 g 156 g 149 g
The balanced chemical equation for the reaction between potassium (K) and chlorine (Cl) to produce potassium chloride (KCl) is:
2K + Cl2 -> 2KCl
According to the Law of Conservation of Mass, the total mass of the reactants will be equal to the total mass of the products.
The molar mass of potassium (K) is 39.1 g/mol and the molar mass of chlorine (Cl) is 35.5 g/mol.
To find the mass of the product (2KCl), first calculate the moles of potassium (K) and chlorine (Cl) present:
moles of K = 78 g / 39.1 g/mol = 2 mol K
moles of Cl = 71 g / 35.5 g/mol = 2 mol Cl
Since the balanced chemical equation shows a 2:1 ratio between K and KCl, the moles of KCl formed will be the same as the moles of K present.
moles of KCl = 2 mol K
Finally, calculate the mass of 2KCl:
mass of 2KCl = moles of KCl x molar mass of KCl = 2 mol KCl x (39.1 g/mol + 35.5 g/mol) = 2 mol KCl x 74.6 g/mol = 149.2 g
Therefore, the mass of the product (2KCl) is 149.2 g.