2 grams of potassium (K) reacts with 5 grams of Oxygen (O). According to the Law of Conservation of Mass, how many grams of potassium oxide (K2O) will be produced? (1 point)
Responses
7 grams
2 grams
5 grams
10 grams
The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction. Therefore, the total mass of the reactants should be equal to the total mass of the products.
The molar mass of potassium (K) is 39.10 g/mol, and the molar mass of oxygen (O) is 16.00 g/mol.
The molar ratio between K and K2O is 2:1. This means that for every 2 moles of K reacted, 1 mole of K2O is produced.
To find the number of moles of K2O produced, we first need to convert the mass of K and O to moles.
Number of moles of K = mass of K / molar mass of K
= 2 g / 39.10 g/mol
= 0.051 mol
Number of moles of O = mass of O / molar mass of O
= 5 g / 16.00 g/mol
= 0.313 mol
Since the molar ratio between K and K2O is 2:1, and since 2 moles of K react with 1 mole of O, we can conclude that the limiting reactant is K, as there are only 0.051 moles available.
Therefore, the number of moles of K2O produced is equal to half the number of moles of K, which is 0.051 / 2 = 0.0255 mol.
Finally, to find the mass of K2O produced, we multiply the number of moles by the molar mass of K2O:
Mass of K2O = number of moles of K2O * molar mass of K2O
= 0.0255 mol * (39.10 g/mol + 16.00 g/mol)
= 1.3945 g
Therefore, 1.3945 grams of potassium oxide (K2O) will be produced.
whats the answer
The answer is 1.3945 grams.
so 2 grams
Apologies for the earlier mistake. The correct answer is 1.3945 grams, not 2 grams.
To determine the mass of potassium oxide (K2O) produced, we need to balance the equation for the reaction between potassium and oxygen:
4K + O2 -> 2K2O
According to the balanced equation, 4 moles of potassium react with 1 mole of oxygen to produce 2 moles of potassium oxide.
To start, we need to convert the given masses of potassium and oxygen to moles:
Mass of potassium (K) = 2 g
Molar mass of potassium (K) = 39.10 g/mol
Number of moles of potassium = Mass of potassium / Molar mass of potassium
= 2 g / 39.10 g/mol
≈ 0.051 mol
Mass of oxygen (O) = 5 g
Molar mass of oxygen (O) = 16.00 g/mol
Number of moles of oxygen = Mass of oxygen / Molar mass of oxygen
= 5 g / 16.00 g/mol
≈ 0.313 mol
Using the balanced equation, we can determine the limiting reactant:
From 4 moles of potassium, we can produce 2 moles of potassium oxide.
From the calculation, we have 0.051 moles of potassium, which is less than half of what is required to produce 2 moles of potassium oxide. Therefore, potassium is the limiting reactant.
Using the stoichiometry of the balanced equation, we can determine the moles of potassium oxide produced:
From 4 moles of potassium, we can produce 2 moles of potassium oxide.
Number of moles of potassium oxide = (Number of moles of potassium / Moles of potassium) * Moles of potassium oxide
= (0.051 mol / 4 mol) * 2 mol
≈ 0.0255 mol
Finally, we can calculate the mass of potassium oxide using the molar mass of K2O:
Molar mass of potassium oxide (K2O) = (39.10 g/mol * 2) + 16.00 g/mol
≈ 94.20 g/mol
Mass of potassium oxide (K2O) = Number of moles of potassium oxide * Molar mass of potassium oxide
= 0.0255 mol * 94.20 g/mol
≈ 2.40 grams
Therefore, according to the Law of Conservation of Mass, approximately 2.40 grams of potassium oxide (K2O) will be produced. Hence, the correct answer is 2 grams.
To determine how many grams of potassium oxide (K2O) will be produced, we need to calculate the molecular weights of potassium (K) and oxygen (O), and then use stoichiometry to find the ratio of reactants to products.
1. Find the molecular weights of potassium (K) and oxygen (O):
- The atomic weight of potassium (K) is approximately 39.10 grams/mol.
- The atomic weight of oxygen (O) is approximately 16.00 grams/mol.
2. Calculate the molar quantities of potassium (K) and oxygen (O):
- Given that we have 2 grams of potassium (K), we can calculate the number of moles using the molar mass:
moles of K = mass of K / molar mass of K = 2 grams / 39.10 g/mol ≈ 0.051 moles.
- Similarly, for the 5 grams of oxygen (O):
moles of O = mass of O / molar mass of O = 5 grams / 16.00 g/mol ≈ 0.313 moles.
3. Determine the stoichiometric ratio between reactants and products using the balanced equation:
- The balanced equation for the reaction is 4K + O2 → 2K2O.
- According to this equation, 4 moles of K react with 1 mole of O2 to produce 2 moles of K2O.
4. Calculate the quantity of potassium oxide (K2O) produced:
- Using the stoichiometric ratio, we can determine the number of moles of K2O produced:
moles of K2O = (moles of K / 4) * 2 = (0.051 moles / 4) * 2 ≈ 0.051 moles.
- Finally, we can calculate the mass of K2O produced using the molar mass of K2O (94.20 g/mol):
mass of K2O = moles of K2O * molar mass of K2O = 0.051 moles * 94.20 g/mol ≈ 4.81 grams.
Therefore, according to the Law of Conservation of Mass, approximately 4.81 grams of potassium oxide (K2O) will be produced. Hence, none of the given responses (7 grams, 2 grams, 5 grams, or 10 grams) is correct.