# chem sorry the last one did not have the question

A sample of PCl5 weighing 2.69 grams is placed in a 1.000 liter flask and vaporized completely at 250 o C.
The final pressure observed at this temperature is 1.000 atmospheres. Note that some, but not all of the PCl5 decomposes according to the equation: PCl5 (g) ---------> PCl3 (g) + Cl2 (g)
What are the pressures ( in atm) of PCl5 , PCl3 and Cl2 once the reaction is complete and at equilibrium ?

1. 👍
2. 👎
3. 👁
1. I assume you don't need a Kp but if you have one listed, please let me know. I believe this is the way to solve the problem although it seems the long way around to me.
moles PCl5 initially = 2.69/molar mass PCl5 = about 0.0129 but you need to confirm ALL of these numbers.
Total moles AT EQUILIBRIUM from PV = nRT. Plug in P, V, R, and T, and I get something like 0.0233 for total moles AT EQUILIBRIUM (not starting.

...........PCl5 ==> PCl3 + Cl2
initial...0.0129......0.....0
change......-x........x.....x
equil....0.0129-x.....x.....x

total moles at equilibrium = 0.0129 - x + x + x = 0.0233
x = 0.0104 and 0.0129-x = 0.0025.

Now solve PV = nRT three times, once for PPCl5, once for PPCl3 and once for PCl2 using the value for T, n (x), R, and total P of 1 atm above. The values you get will be the partial pressure of each of the gases at equilibrium and at the conditions listed. Check my thinking.

1. 👍
2. 👎

## Similar Questions

1. ### chemistry

A student placed 19.0g of glucose (c6h12o6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100ml.- mark on the neck of the flask was reached. The

2. ### Chemistry

an empty flask as a mass of 123.4 grams. When the flask is filled with water, the mass is 211.6 grams. If 10.0 grams of zinc (d=7.14 g/cm3) are added to the flask filled with water (and the sides of the flask are dried from the

3. ### chemistry

Ibuprofen, the active ingredient in Advil, is made up of carbon, hydrogen, and oxygen atoms. When a sample of ibuprofen, weighing 5.000 g, burns in oxygen, 13.86g of CO2 and 3.926 g of water are obtained. What is the simplest

4. ### Chemistry

A student placed 17.0 g of glucose (C_6H_{12}O_6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100 mL mark on the neck of the flask was reached. The

A student placed 10.5g of glucose (C6H12O6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100.- mL mark on the neck of the flask was reached. The

2. ### chemistry

A mixture containing 50grams of carbon and 75 grams of oxygen is sealed in a flask. The total mass of the system is 225 grams. The flask is heated to cause the carbon and oxygen to react. The sealed flask is massed. What is the

3. ### chemistry

a 2.00-liter sample of a gas has a mass of 1.80 grams at STP. What is the density , in grams per liter , of this gas at Stp?

4. ### College Chemistry

A student placed 14.0g of glucose (C6H1206) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100.-mL mark on the neck of the flask was reached. The

1. ### Chemistry

A sample of gaseous PCl5 was introduced into an evacuated flask so that the pressure of pure PCl5 would be 0.54 atm at 425 K. However, PCl5 decomposes to gaseous PCl3 and Cl2, and the actual pressure in the flask was found to be

2. ### Chem II

PCl5 dissociates according to the reaction: PCl5(g) ↔ PCl3(g) + Cl2(g). One mole of PCl5 was placed in one liter of solution. When equilibrium was established, 0.5 mole of PCl5 remained in the mixture. What is the equilibrium

3. ### Chemistry

A piece of metal weighing 20.32 grams is added to a flask with a volume of 24.5 cm3. It is found that 18.52 grams of water must be added to the metal to fill the flask. What is the density of the metal?