At 1285°C, the equilibrium constant for the reaction
Br2 (gas) <---> 2Br (gas) is Keq= 1.04 X 10^ -3
A 0.200-L vessel containing an equilibrium mixture of gases has 0.245 g. Br2 (gas) in it. What is the mass of Br (gas) in the vessel? What are the concentrations of Br2 and Br?
0.245 g Br2. 0.245g/159.808 = 0.00153 moles Br2. M = 0.00153 moles/0.200 L = 0.00767 M.
Br2(g) ==> 2Br(g)
Keq = (Br)^2/(Br2) = 1.04E-3
You know (Br2) and you know Keq, solve for (Br) which will be in moles/L. To find g Br, convert (Br) in mols/L to moles in 0.200 L, then to grams (g = moles x molar mass). Post your work if you get stuck.
I'm having some difficulty getting the answer...I completely follow your logic and your numbers make sense, but I end up getting 1.129 as my final answer while the back of the book says it should be 0.00767....
Well, well, it seems like we have some chemistry fun here! Let's get started.
To find the mass of Br (gas) in the vessel, we first need to find the moles of Br2 using its molar mass. The molar mass of Br2 is 159.808 g/mol.
0.245 g of Br2 = (0.245 g) / (159.808 g/mol) = 0.0015338 mol Br2
According to the balanced equation, 1 mol of Br2 reacts to form 2 mol of Br. So, the number of moles of Br will be twice the number of moles of Br2.
Number of moles of Br = 2 * 0.0015338 mol = 0.0030676 mol Br
To find the mass of Br (gas), we multiply the number of moles of Br by its molar mass, which is 79.904 g/mol.
Mass of Br = (0.0030676 mol) * (79.904 g/mol) = 0.245 g Br
So, the mass of Br (gas) in the vessel is 0.245 g.
Now, to find the concentrations of Br2 and Br, we need to divide their respective moles by the volume of the vessel.
Concentration of Br2 = (0.0015338 mol) / (0.200 L) = 0.007669 mol/L
Concentration of Br = (0.0030676 mol) / (0.200 L) = 0.015338 mol/L
There you have it! The mass of Br (gas) in the vessel is 0.245 g, and the concentrations of Br2 and Br are 0.007669 mol/L and 0.015338 mol/L, respectively. Keep on clowning around!
To find the mass of Br (gas) in the vessel, we first need to convert the mass of Br2 to moles using its molar mass.
1. Find the molar mass of Br2:
Br = 79.9 g/mol
Since there are two Br atoms in one molecule of Br2, the molar mass of Br2 is:
Molar mass of Br2 = 2 * Molar mass of Br = 2 * 79.9 g/mol = 159.8 g/mol
2. Convert the mass of Br2 to moles:
Given mass of Br2 = 0.245 g
Number of moles of Br2 = 0.245 g / 159.8 g/mol = 0.001533 mol
Since the balanced equation shows that 1 mole of Br2 forms 2 moles of Br, we can determine the moles of Br gas present in the equilibrium mixture.
3. Moles of Br = 2 * Moles of Br2 = 2 * 0.001533 mol = 0.003066 mol
Now let's find the concentrations of Br2 and Br in the vessel. Concentration is defined as the moles of the substance divided by the volume of the vessel.
4. Concentration of Br2:
Volume of the vessel = 0.200 L (given)
Concentration of Br2 = Moles of Br2 / Volume of the vessel = 0.001533 mol / 0.200 L = 0.007665 mol/L
5. Concentration of Br:
Concentration of Br = Moles of Br / Volume of the vessel = 0.003066 mol / 0.200 L = 0.01533 mol/L
So, the mass of Br (gas) in the vessel is 0.003066 moles and the concentrations of Br2 and Br are 0.007665 mol/L and 0.01533 mol/L, respectively.
To find the mass of Br (gas) in the vessel, we need to know the concentration (in mol/L) of Br (gas) in the equilibrium mixture. We can start by finding the concentration of Br2 (gas) using the given mass and volume of the vessel.
Step 1: Convert the mass of Br2 (gas) to moles
First, we need to convert the given mass of Br2 (gas) to moles. To do this, we use the molar mass of Br2, which is 159.808 g/mol.
moles of Br2 = mass of Br2 / molar mass of Br2
moles of Br2 = 0.245 g / 159.808 g/mol
moles of Br2 = 0.001534 mol
Step 2: Calculate the concentration of Br2 (gas)
The concentration of Br2 (gas) can be calculated by dividing the moles of Br2 by the volume of the vessel in liters (0.200 L).
concentration of Br2 = moles of Br2 / volume of vessel
concentration of Br2 = 0.001534 mol / 0.200 L
concentration of Br2 = 0.00767 mol/L
Now, we can use the equilibrium constant (Keq) to determine the concentrations of Br2 and Br.
Step 3: Use Keq to calculate the concentration of Br (gas)
The equation for the reaction is: Br2 (gas) <---> 2Br (gas)
According to the stoichiometry of the reaction, the concentration of Br2 (gas) is divided by 2 to get the concentration of Br (gas).
concentration of Br = concentration of Br2 / 2
concentration of Br = 0.00767 mol/L / 2
concentration of Br = 0.003835 mol/L
Step 4: Calculate the mass of Br (gas) in the vessel
Finally, we can calculate the mass of Br (gas) in the vessel by multiplying the concentration of Br (gas) by the volume of the vessel in liters and the molar mass of Br.
mass of Br = concentration of Br * volume of vessel * molar mass of Br
mass of Br = 0.003835 mol/L * 0.200 L * 79.904 g/mol
mass of Br = 0.01534 g
Therefore, the mass of Br (gas) in the vessel is approximately 0.01534 g, and the concentrations of Br2 and Br are approximately 0.00767 mol/L and 0.003835 mol/L, respectively.