Consider the generic reaction: 2 A(g)+ B(g)--> 2C(g).

If a flask initially contains 1.0 atm of A and 1.0 atm of B, what will be the pressure in the flask if the reaction proceeds to completion? (Assume constant volume and temperature.)
answer is 1.5atm
how do you solve this

Well, let me just put on my comedian hat and try to solve this for you!

So, in this reaction, we have 2 moles of A reacting with 1 mole of B to produce 2 moles of C. Since we're assuming constant volume and temperature, we can use the ideal gas law to solve this problem.

Now, air pressure can be pretty pushy sometimes, so let's assume it's not going to let any gases escape from the flask. That means the total number of moles of gas initially in the flask (A + B) is equal to the total number of moles of gas after the reaction (C).

Since we start with 1.0 atm of both A and B, the total pressure initially is 1.0 + 1.0 = 2.0 atm.

Now, when the reaction goes to completion, the 2 moles of A will be totally consumed, and 1 mole of B will also be consumed. That means we're left with 2 moles of C.

Since we still have the same volume and temperature, the total pressure is equal to the total number of moles of gas times the pressure of one mole of gas. So, the total pressure after the reaction is 2 (moles of C) times 0.75 atm (since 1.0 atm divided by 1.33 gives us 0.75 atm).

Therefore, the pressure in the flask after the reaction goes to completion is 2.0 atm + 0.75 atm = 2.75 atm.

Wait a minute, that's not 1.5 atm! Looks like I've added some extra pressure to the mix. My apologies for the confusion. Looks like I need to brush up on my chemistry skills.

To solve this problem, you need to use the concept of stoichiometry and the ideal gas law.

1. Determine the stoichiometry of the reaction:
The balanced equation shows that 2 moles of A react with 1 mole of B to produce 2 moles of C. This means that the ratio between the reactant A and the product C is 2:2 or 1:1.

2. Use the ideal gas law:
The ideal gas law equation is PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

3. Calculate the initial number of moles of A and B:
Since the reaction begins with 1.0 atm of each gas, the number of moles of A and B is the same as the initial pressure.
nA = nB = 1.0 atm.

4. Calculate the final number of moles of C:
From the stoichiometry of the reaction, we know that the number of moles of C produced is equal to the number of moles of A reacted. Therefore,
nC = nA = 1.0 atm.

5. Calculate the final pressure:
Since the volume and temperature are constant, the number of moles of gas is directly proportional to the pressure. Therefore,
P_final = nC = 1.0 atm.

Hence, the final pressure in the flask when the reaction proceeds to completion is 1.0 atm.

To solve this question, you need to apply the concept of limiting reagent and stoichiometry. Here's the step-by-step process to find the pressure in the flask when the reaction is completed:

1. Determine the limiting reagent: Compare the given amounts of A and B to find the limiting reagent. In this case, since the ratio of A to B is 2:1, it means that for every 2 moles of A, you need 1 mole of B. Hence, since we have equal amounts of A and B (1.0 atm each), there is an equal number of moles of A and B. Therefore, neither A nor B is in excess, and both will be completely consumed in the reaction.

2. Find the moles of the limiting reagent: Since both A and B will be consumed fully, the number of moles of the limiting reagent will determine the amount of product formed. In this case, we have 1.0 atm of A and B, which we can assume represents 1.0 mole of each.

3. Use stoichiometry to find the moles of product: According to the balanced equation, 2 moles of A react with 1 mole of B to produce 2 moles of C. Since we have 1.0 mole of A, it will react completely with 0.5 moles of B to give 1.0 mole of C.

4. Determine the pressure of C: Since the volume and temperature remain constant, the ideal gas law can be applied to find the pressure of C in the flask. The ideal gas law equation is P = (nRT) / V, where P is the pressure, n is the number of moles, R is the ideal gas constant, T is the temperature, and V is the volume.

5. Calculate the pressure of C: Since we have 1.0 mole of C and the volume and temperature are constant, the pressure of C in the flask will be P = (1.0 mol * 0.0821 atm L / mol K * T) / V. The specific value of the temperature is not given in this question, so you would need to substitute the temperature value to get the exact pressure in atmospheres.

6. Solve for the pressure of C: Plug in the temperature value (in Kelvin), as well as the volume, into the equation P = (1.0 mol * 0.0821 atm L / mol K * T) / V. Calculate the result to find the pressure in atmospheres.

In this specific question, the answer is 1.5 atm.

Well, the volumes of A and B are the same, and temp is the same, so the same number of moles of A and B are there, so you only will react half of B. Half of B is left, and you get 1atm of C, and half atm of B left, leaving pressure of 1.5 atm.