This is my last question and this one really threw me for a loop. I know that the temp has to be converted to kelvin which would make it 315.4
What volume of oxygen gas can be collected at 0.683 atm pressure and 34.0◦C when 42.4g of KClO3 decompose by heating, according to the following equation?
2KClO3(s)->2KCl(s) + 3O2(g)
Answer in units of L
You need to rethink this.
K = 273 + 34 which is NOT 315.4.
2KClO3(s)->2KCl(s) + 3O2(g)
mols KClO3 = grams molar mass = ?
Using the coefficients in the balanced equation, convert mols KClO3 to mols O2 gas. Then substitute n into PV = nRT and solve for V in liters at the conditions listed. Use P = 0.683 atm, R is 0.08206 L*atm/mol*K, T is 273 + 34 = ? and n from above.
To find the volume of oxygen gas that can be collected, we can use the Ideal Gas Law equation:
PV = nRT
Where:
P = pressure in atm
V = volume in liters (this is what we're trying to find)
n = number of moles
R = ideal gas constant
T = temperature in Kelvin
First, let's convert the given temperature from Celsius to Kelvin. We add 273.15 to the temperature in Celsius to get Kelvin.
T = 34.0°C + 273.15 = 307.15 K
Next, we need to find the number of moles of oxygen gas produced. We can do this by converting the given mass of KClO3 to moles using its molar mass. The molar mass of KClO3 is:
K: 39.10 g/mol
Cl: 35.45 g/mol
O: 16.00 g/mol
Molar mass of KClO3 = 39.10 g/mol + 3 * (35.45 g/mol) + 3 * (16.00 g/mol) = 122.55 g/mol
Using the molar mass, we can find the number of moles of KClO3:
n = mass (g) / molar mass (g/mol)
n = 42.4 g / 122.55 g/mol
Now that we have the number of moles of KClO3, we can use the stoichiometry of the balanced equation to determine the number of moles of oxygen gas produced. From the balanced equation, we see that for every 2 moles of KClO3, 3 moles of O2 are produced.
n(O2) = n(KClO3) * (3 moles O2 / 2 moles KClO3)
Finally, we can substitute the values into the Ideal Gas Law equation to find the volume of oxygen gas:
PV = nRT
V = (n * R * T) / P
Given values:
P = 0.683 atm
T = 307.15 K
n = moles of O2 (calculated in the previous step)
R = ideal gas constant = 0.0821 L·atm/(mol·K)
Now we can calculate the volume:
V = (n * R * T) / P
Plug-in the given values and calculate the volume. Make sure to use the correct units and significant figures to match the question's requirement.