How many grams of potassium are needed in the reaction to produce 23.5 grams of potassium oxide
23.5 g
19.5 g
9.75 g
0.50 g
To find out how many grams of potassium are needed to produce 23.5 grams of potassium oxide, we need to look at the stoichiometry of the reaction and use the concept of mole ratio.
The balanced chemical equation for the reaction between potassium and oxygen to produce potassium oxide is:
4K + O2 -> 2K2O
From this equation, we can determine that for every 4 moles of potassium (K) reacted, 2 moles of potassium oxide (K2O) are produced.
To calculate the amount of potassium needed, we can set up a proportional relationship using the mole ratio:
4 moles K / 2 moles K2O = X grams K / 23.5 grams K2O
To solve for X, we first need to convert the given mass of potassium oxide (23.5 grams) to moles. We can do this by dividing the mass by the molar mass of potassium oxide, which is calculated by adding the atomic masses of its constituent elements:
Molar mass of K2O = (2*atomic mass of K) + atomic mass of O = (2*39.10 g/mol) + 16.00 g/mol = 94.20 g/mol
Now, we can calculate the number of moles of potassium oxide:
Moles of K2O = Mass of K2O / Molar mass of K2O = 23.5 g / 94.20 g/mol ≈ 0.249 moles K2O
Next, we can use the mole ratio from the balanced equation to determine the number of moles of potassium required:
Moles of K = (Moles of K2O * 4) / 2 = (0.249 mol * 4) / 2 = 0.498 moles K
Finally, we can convert moles of potassium to grams by using its molar mass, which is calculated by adding the atomic mass of potassium:
Molar mass of K = 39.10 g/mol
Grams of K = Moles of K * Molar mass of K = 0.498 mol * 39.10 g/mol ≈ 19.46 g
Therefore, approximately 19.5 grams of potassium are needed to produce 23.5 grams of potassium oxide. Therefore, the correct answer is option b) 19.5 g.
To determine the amount of potassium needed to produce 23.5 grams of potassium oxide, you need to know the molar ratio between potassium and potassium oxide.
The molar ratio between potassium and potassium oxide can be found by balancing the chemical equation for the reaction. Based on the balanced equation, we can see that for every 2 moles of potassium, 1 mole of potassium oxide is produced.
Since we know the molar mass of potassium is 39.10 g/mol and the molar mass of potassium oxide is 94.20 g/mol, we can use these values to set up a proportion to find the amount of potassium needed.
(39.10 g K/2 mol K) = (23.5 g K2O/94.20 g K2O)
Simplifying the equation, we get:
39.10 g K = (23.5 g K2O)(2 mol K/94.20 g K2O)
Now, let's solve for the mass of potassium:
39.10 g K = (23.5 g K2O)(2/94.20)
39.10 g K = (47 g K2O/94.20)
39.10 g K = 0.50 g K
Therefore, the answer is 0.50 g.
how many moles of K2O in 23.5 g?
the equation will tell you how many moles of K will be used.
Convert that back to grams.