How many grams of potassium nitrate (KNO3) are required to produce 536 g of potassium nitrite (KNO2) according to the equation below?
*I've tried this question for so long and I get so many different answers in the end so please help.
I forgot to add the equation so here it is:
2KNO3(s) ---> 2KNO2(s) + O2(g)
The mole ratio is 1:1, so figure the moles of potasium nutrite in 536g.
Then figure the number of grams in that same number of moles of postassium nitrate.
Moles of potassium nitrite (in 536g) would be 6.29 or 6.3 moles, correct?
Yes but I would keep the 6.29 since the 536 allows for three significant figures. Don't throw numbers away unless it's necessary.
To find out how many grams of potassium nitrate (KNO3) are required to produce 536 g of potassium nitrite (KNO2), you need to use stoichiometry, which is the relationship between the amounts of substances involved in a chemical reaction.
First, let's write the balanced chemical equation for the reaction:
2 KNO3 -> 2 KNO2 + O2
From the equation, we can see that 2 moles of KNO3 are required to produce 2 moles of KNO2.
Now, to solve the problem, follow these steps:
Step 1: Convert the given mass of KNO2 to moles.
To do this, you need to know the molar mass of KNO2. Potassium (K) has a molar mass of 39.10 g/mol, nitrogen (N) has a molar mass of 14.01 g/mol, and oxygen (O) has a molar mass of 16.00 g/mol. Adding these up, the molar mass of KNO2 is:
39.10 g/mol (K) + 14.01 g/mol (N) + (16.00 g/mol (O) * 2) = 85.11 g/mol (KNO2)
Now, use the molar mass to convert the given mass of KNO2 to moles:
536 g KNO2 * (1 mol KNO2 / 85.11 g KNO2) = 6.30 mol KNO2
Step 2: Determine the molar ratio between KNO2 and KNO3 from the balanced equation.
From the balanced equation, we see that 2 moles of KNO3 are required to produce 2 moles of KNO2. Therefore, the molar ratio is 1:1.
Step 3: Convert the moles of KNO2 to the moles of KNO3 using the molar ratio.
Since the molar ratio is 1:1, the moles of KNO3 required will be the same as the moles of KNO2:
6.30 mol KNO2 * (1 mol KNO3 / 1 mol KNO2) = 6.30 mol KNO3
Step 4: Convert the moles of KNO3 to grams.
To do this, you'll need to know the molar mass of KNO3. Potassium (K) has a molar mass of 39.10 g/mol, nitrogen (N) has a molar mass of 14.01 g/mol, and oxygen (O) has a molar mass of 16.00 g/mol. Adding these up, the molar mass of KNO3 is:
39.10 g/mol (K) + 14.01 g/mol (N) + (16.00 g/mol (O) * 3) = 101.10 g/mol (KNO3)
Now, use the molar mass to convert the moles of KNO3 to grams:
6.30 mol KNO3 * (101.10 g KNO3 / 1 mol KNO3) = 636.33 g KNO3 (rounded to four decimal places)
Therefore, approximately 636.33 grams of potassium nitrate (KNO3) are required to produce 536 grams of potassium nitrite (KNO2) according to the given equation.