Potassium nitrate decomposes on heating, producing potassium oxide and gaseous nitrogen and oxygen:
4KNO3(s)--> 2K2O(s) + 2N2(g) + 5O2(g)
To produce 56.6 kg of oxygen, how many (a) moles of KNO3 must be heated? (b) Grams of KNO3 must must heated?
First, I don't believe for a minute that KNO3 decomposes on heating to produce K2O, N2 and O2; however, we can calculate whatever we wish.
Convert 56.6 kg oxygen to moles. Moles = grams/molar mass.
Using the coefficients in the balanced equation, convert moles oxygen to moles KNO3. That's part a.
For part b, convert moles KNO3 to grams. grams = moles x molar mass.
.3mol
b.404g
3.5375
To determine the answer, we need to use the stoichiometry of the chemical reaction provided and perform some calculations. Let's break down the problem into two parts:
(a) To find the number of moles of KNO3 required to produce 56.6 kg of oxygen:
1. Start by determining the molar mass of oxygen (O2):
- Oxygen (O) has a molar mass of 16.00 g/mol.
- Since there are two oxygen atoms in each O2 molecule, the molar mass of O2 is 2 * 16.00 g/mol = 32.00 g/mol.
2. Calculate the number of moles of oxygen:
- Given mass of oxygen = 56.6 kg = 56600 g
- Number of moles of oxygen = Given mass / molar mass = 56600 g / 32.00 g/mol
3. Determine the balanced stoichiometric coefficients in the chemical reaction:
- From the balanced equation, the stoichiometric coefficient for oxygen (O2) is 5.
4. Use the stoichiometry to find the moles of KNO3:
- Since the stoichiometric coefficient for oxygen is 5, the number of moles of KNO3 would be 5 times the number of moles of oxygen.
(b) To find the grams of KNO3 required to produce 56.6 kg of oxygen:
1. Follow the same steps as in part (a) to determine the number of moles of KNO3 required.
2. Convert moles of KNO3 to grams:
- Given moles of KNO3 * molar mass of KNO3 = grams of KNO3
Now, let's perform the calculations:
(a) Moles of KNO3:
Number of moles of oxygen = 56600 g / 32.00 g/mol
Moles of KNO3 = Number of moles of oxygen * (1 mole of KNO3/ 5 moles of O2)
(b) Grams of KNO3:
Grams of KNO3 = Moles of KNO3 * Molar mass of KNO3
To obtain the final answers, substitute the relevant values into the equations above and calculate.