Calculating the Value of X in Compound KClOx Based on Decomposition Reaction
In the lab, a 156 g sample of unknown compound KClOx was completely decomposed to produce 50.4 L of O2 (g) at STP and an unknown amount of KCl. What is the value of X?
Answer:
2
Explanation:
Step 1: Write the generic decomposition reaction
KClOₓ ⇒ KCl + O₂
Step 2: Calculate the moles of O₂
At STP, 1 mole of an ideal gas occupies 22.4 L.
50.4 L × 1 mol/22.4 L = 2.25 mol
Step 3: Calculate the mass corresponding to 2.25 moles of O₂
The molar mass of O₂ is 32.00 g/mol.
2.25 mol × 32.00 g/mol = 72 g
Step 4: Determine the value of x
Every 156 g of KClOₓ there are 72 g of oxygen. The mass percent of O is:
%O: 72 g/156 g × 100% = 46.2%
In KClO, the mass percent of O is: 32.00 g/90.5 g × 100% = 35.4%
In KClO₂, the mass percent of O is: 64.00 g/138.5 g × 100% = 46.2%
Then, x = 2
Final answer:
To find the value of x in KClOx, we can use stoichiometry and the ideal gas law. First, convert the mass of KClOx to moles and then use the balanced equation to determine the moles of oxygen gas produced. Finally, convert the moles of KClOx to the molar mass to find the value of x.
Explanation:
In this question, we are given the mass of a sample of compound KClOx and the volume of oxygen gas produced during its decomposition. To find the value of x in KClOx, we can use stoichiometry and the ideal gas law.
First, we need to convert the mass of KClOx to moles by dividing it by the molar mass of KClOx. Then, we can use the balanced equation of the decomposition reaction to determine the moles of oxygen gas produced. Since the temperature and pressure of the oxygen gas are given at STP, we can use the ideal gas law to convert the moles of oxygen gas to its volume.
Once we have the moles of oxygen gas produced and the volume of oxygen gas, we can use the mole ratio from the balanced equation to determine the moles of KClOx. Finally, we can convert the moles of KClOx to the molar mass of KClOx and find the value of x.