78 g of potassium (K)%C2%A0react 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)?%C2%A0(1 point) Responses
149 g
156 g
2 g
4 g
The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction. Therefore, the mass of the reactants must equal the 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 determine the mass of the product (2KCl), we need to calculate the mass of potassium chloride (KCl) formed.
The molar mass of potassium chloride (KCl) is 74.55 g/mol (39.1 g/mol + 35.5 g/mol).
To find the mass of the product (2KCl), we need to calculate the number of moles of potassium (K) and chlorine (Cl) using their given masses and their respective molar masses.
Number of moles of potassium (K) = mass of potassium (K) / molar mass of potassium (K)
= 78 g / 39.1 g/mol
= 1.995 moles
Number of moles of chlorine (Cl) = mass of chlorine (Cl) / molar mass of chlorine (Cl)
= 71 g / 35.5 g/mol
= 2 moles
According to the Law of Conservation of Mass, the moles of the reactants must be equal to the moles of the product.
In this case, since 2 moles of chlorine (Cl) react with 1.995 moles of potassium (K), we can conclude that the limiting reagent is potassium (K) because it is not completely consumed.
The number of moles of potassium chloride (KCl) formed will be half of the number of moles of the limiting reagent, which is 0.9975 moles (1.995 moles / 2).
Now, we can calculate the mass of the product (2KCl) using the mass of potassium chloride (KCl) and its molar mass.
Mass of potassium chloride (KCl) = moles of potassium chloride (KCl) x molar mass of potassium chloride (KCl)
= 0.9975 moles x 74.55 g/mol
= 74.24 g
Since 2KCl represents twice the molar mass of potassium chloride (KCl), the mass of the product (2KCl) will be twice the mass of potassium chloride (KCl).
Mass of the product (2KCl) = 2 x mass of potassium chloride (KCl)
= 2 x 74.24 g
= 148.48 g
Rounded to the nearest whole number, the mass of the product (2KCl) is 149 g.
Therefore, the correct answer is:
The mass of the product (2KCl) is 149 g.
To determine the mass of the product, we need to calculate the total mass of potassium chloride produced when 78 g of potassium reacts with 71 g of chlorine.
The molar mass of potassium (K) is 39.10 g/mol, and the molar mass of chlorine (Cl) is 35.45 g/mol.
First, we need to find the number of moles of potassium (K) and chlorine (Cl) using their masses and molar masses:
Number of moles of potassium (K) = mass of potassium (K) / molar mass of potassium (K)
Number of moles of potassium (K) = 78 g / 39.10 g/mol
Number of moles of potassium (K) = 1.995 mol
Number of moles of chlorine (Cl) = mass of chlorine (Cl) / molar mass of chlorine (Cl)
Number of moles of chlorine (Cl) = 71 g / 35.45 g/mol
Number of moles of chlorine (Cl) = 2.003 mol
Next, we need to determine the limiting reactant, which is the reactant that is completely consumed and determines the amount of product formed.
Since the ratio of potassium (K) to chlorine (Cl) in the balanced chemical equation for the reaction is 2:1, we can see that potassium (K) is the limiting reactant. This means that all of the potassium (K) will react, while there will be excess chlorine (Cl).
Finally, we can calculate the mass of the product, potassium chloride (2KCl), using the number of moles of potassium (K) and the molar mass of potassium chloride (KCl):
Mass of product, potassium chloride (2KCl) = (2 moles of potassium (K) + 2 moles of chlorine (Cl)) x molar mass of potassium chloride (KCl)
Mass of product, potassium chloride (2KCl) = (2 x 1.995 mol + 2 x 2.003 mol) x (39.10 g/mol + 35.45 g/mol)
Mass of product, potassium chloride (2KCl) = (3.99 mol + 4.006 mol) x 74.55 g/mol
Mass of product, potassium chloride (2KCl) = 7.996 mol x 74.55 g/mol
Mass of product, potassium chloride (2KCl) = 595.69 g
Therefore, the mass of the product, potassium chloride (2KCl), is approximately 596 g.
None of the given options are correct.
To find the mass of the product (2KCl) using the Law of Conservation of Mass, you need to calculate the total mass of the reactants (potassium and chlorine) and then compare it to the total mass of the product.
Given:
Mass of potassium (K) = 78 g
Mass of chlorine (Cl) = 71 g
To calculate the total mass of the reactants:
Total mass of reactants = Mass of potassium + Mass of chlorine
Total mass of reactants = 78 g + 71 g
Total mass of reactants = 149 g
According to the Law of Conservation of Mass, the total mass of the reactants must be equal to the total mass of the products. Therefore, the mass of the product (2KCl) will also be 149 g.
So, the correct answer is:
149 g