In this reaction, 4.58 L of O2 were formed at 745mm Hg and 308 K. How many grams of Ag2O decomposed.
2 Ag2O----> 4 Ag + O2
Please help I'm very confused
As Dr. Bob said:
Use PV=nRT to solve for n = moles of oxygen
Convert 745mmHg to 1 atm, thats 745mmHg x 1 atm/760mmHg = 0.98atm
(0.98)(4.58L)/(0.0821)(308K) = 0.18mol O2
Use Stoichiometry to convert O2 moles to moles Ag20, then convert that to grams Ag2O
0.18molO2 x 2molAg2O/1molO2 x 231.735gAg2O/1molAg2O = 83.4gAg2O
*the exact answer is 82.3g bc I rounded different then the book, but this is how you get to that number
To determine the mass of Ag2O decomposed, we need to use the given information about the volume of O2 gas formed. Here's how you can calculate it:
Step 1: Convert the volume of O2 gas (4.58 L) to moles using the ideal gas law equation: PV = nRT.
PV = nRT
(745 mmHg) * (4.58 L) = n * (0.0821 L*atm/mol*K) * (308 K)
Convert mmHg to atm:
P = (745 mmHg) * (1 atm / 760 mmHg) = 0.980 atm
(0.980 atm) * (4.58 L) = n * (0.0821 L*atm/mol*K) * (308 K)
Step 2: Calculate the number of moles of O2 gas formed.
n = (0.980 atm * 4.58 L) / (0.0821 L*atm/mol*K * 308 K)
Step 3: Determine the stoichiometric ratio between Ag2O and O2 using the balanced equation.
From the balanced equation: 2 Ag2O → 4 Ag + O2
For every 2 moles of Ag2O, 1 mole of O2 is produced. Therefore, the ratio between Ag2O and O2 is 2:1.
Step 4: Calculate the moles of Ag2O decomposed.
Since the ratio of Ag2O to O2 is 2:1, the moles of Ag2O decomposed is half the moles of O2 formed.
moles of Ag2O decomposed = (1/2) * n (calculated in Step 2)
Step 5: Convert moles of Ag2O decomposed to grams using the molar mass of Ag2O.
The molar mass of Ag2O can be calculated as follows:
2(Ag) + 1(O) = 2(107.87 g/mol Ag) + 16.00 g/mol O = 231.74 g/mol Ag2O
Mass of Ag2O decomposed = moles of Ag2O decomposed * molar mass of Ag2O
Now, you can plug in the calculated values from the previous steps to find the mass of Ag2O decomposed.
Use PV = nRT and solve for n = moles oxygen.
Use stoichiometry to convert moles O2 to moles Ag2O, convert to grams Ag2O