What does the Law of Conservation of Mass state?(1 point)
The Law of Conservation of Mass states that mass cannot be created or destroyed in a chemical reaction, but can only be rearranged.
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artasticdrawing
09/08/2022
Chemistry
High School
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Pls Help ASAP! 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?
O 10 grams
O 7 grams
O 2 grams
O 5 grams
According to the Law of Conservation of Mass, the total mass of the reactants must equal the total mass of the products.
In this case, 2 grams of potassium (K) reacts with 5 grams of oxygen (O).
To find the mass of potassium oxide (K2O) produced, we can look at the balanced chemical equation:
2K + O2 -> 2K2O
From the balanced equation, we can see that 2 moles of K react with 1 mole of O2 to produce 2 moles of K2O.
The molar mass of K2O is 94 grams. Therefore, 2 moles of K2O is equal to 188 grams.
Since the balanced equation shows that 2 moles of K react to produce 2 moles of K2O, we can conclude that the mass of K2O produced will be equal to the mass of K used.
Therefore, the answer is 2 grams.
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 5 grams
Apologies for the mistake in my previous response. Let's re-calculate it correctly.
According to the balanced chemical equation:
4K + O2 → 2K2O
We can see that 4 moles of K react with 1 mole of O2 to produce 2 moles of K2O.
To find the number of moles of K and O2, we can use the formula:
moles = mass / molar mass
For K:
moles of K = 2 g / 39.1 g/mol (molar mass of K) = 0.051 mol
For O2:
moles of O2 = 5 g / 32 g/mol (molar mass of O2) = 0.156 mol
From the balanced equation, we can see that the ratio of K2O to K is 2:4, which simplifies to 1:2. Therefore, the moles of K2O produced will be half of the moles of K.
moles of K2O = 0.051 mol / 2 = 0.0255 mol
To find the mass of K2O:
mass = moles × molar mass
mass of K2O = 0.0255 mol × 94.2 g/mol (molar mass of K2O) = 2.42 grams
Therefore, according to the Law of Conservation of Mass, 2 grams of potassium will react with 5 grams of oxygen to produce 2.42 grams of potassium oxide (K2O).
If the mass of elements before a chemical reaction is 30 grams, after the chemical reaction, the mass will be __.
28 grams
0 grams
30 grams
32 grams
3. 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)?
2 g
149 g
156 g
4 g
If the mass of elements before a chemical reaction is 30 grams, according to the Law of Conservation of Mass, the mass of the elements after the chemical reaction will still be 30 grams.
what is the answer?
Apologies for the confusion. Let's calculate the answer correctly.
According to the Law of Conservation of Mass, the mass of the reactants before a chemical reaction should be equal to the mass of the products after the chemical reaction.
In the given scenario, 78 grams of potassium (K) react with 71 grams of chlorine (Cl) to produce potassium chloride (KCl). So we need to find the mass of 2KCl, which is the product.
The molar mass of KCl is 74.55 g/mol (39.1 g/mol for K + 35.45 g/mol for Cl).
To find the mass of 2KCl:
mass = moles × molar mass
First, let's calculate the number of moles for each reactant:
moles of K = 78 g / 39.1 g/mol = 1.995 mol
moles of Cl = 71 g / 35.45 g/mol = 2.004 mol
From the balanced chemical equation, we can see that the ratio of K to KCl is 2:2. So, the moles of KCl produced will be the same as the moles of K used.
moles of KCl = 1.995 mol
Now, calculate the mass of 2KCl:
mass = moles × molar mass
mass of 2KCl = 1.995 mol × 74.55 g/mol = 149 grams
Therefore, according to the Law of Conservation of Mass, the mass of the product 2KCl will be 149 grams.