help please. i don't even know where to start
An empty glass container has a mass of 658.572 g. It has a mass of 659.452 g after it has been filled with nitrogen gas at a pressure of 790. torr and a temperature of 15?C. When the container is evacuated and refilled with a certain element (A) at a pressure of 745 torr and a temperature of 26?C, it has a mass of 660.59 g.
Compound B, a gaseous organic compound that consists of 85.6% carbon and 14.4% hydrogen by mass, is placed in a stainless steel vessel (10.68L) with excess oxygen gas. The vessel is placed in a constant-temperature bath at 22?C. The pressure in the vessel is 11.98 atm. In the bottom of the vessel is a container that is packed with Ascarite and a dessicant. Ascarite is asbestos impregnated with sodium hydroxide; it quantitatively absorbs carbon dioxide:
2NaOH (s) + CO2 (g) „³ Na2CO3 (s) + H2O (l)
The dessicant is anhydrous magnesium perchlorate, which quantitatively absorbes the water produced by the combustion reaction as well as the water produced by the above reaction. Neither the Ascarite nor the desiccant reacts with the compound B or oxygen. The total mass of the container with the Ascarite and desiccant is 765.3 g.
The combustion reaction of compound B is initiated by a spark. The pressure immediately rises, then begins to decrease, and finally reaches a steady value of 6.02 atm. The stainless stell vessel is carefully opened, and the mass of the container inside the vessel is found to be 846.7 g.
A and B react quantitatively in a 1:1 mole ratio to form one mole of the single product, gas C.
a. How many grams of C will be produced if 10.0L of A and 8.60: of B (each at STP) are reacted by opening a stopcock connecting the two samples?
b. What will be the total pressure in the system
To solve this problem, let's break it down step by step.
1. Calculate the number of moles of nitrogen gas in the glass container:
Mass of nitrogen gas = Mass of filled container - Mass of empty container
Convert the masses from grams to moles using the molar mass of nitrogen gas (28.0134 g/mol).
2. Calculate the number of moles of element A in the container:
Mass of element A = Mass of container with A - Mass of container without A
Convert the masses from grams to moles using the molar mass of A (which is not provided in the question).
3. Calculate the number of moles of element B in the container:
Mass of element B = Mass of container with B - Mass of container without B
Convert the masses from grams to moles using the molar mass of B (which is not provided in the question).
4. Determine the limiting reactant between A and B:
The limiting reactant is the one that is completely consumed in the reaction and determines the maximum amount of product that can be formed. Compare the moles of A and B calculated in steps 2 and 3 to identify the limiting reactant.
5. Calculate the theoretical yield of product C:
The theoretical yield is the maximum amount of product that can be formed based on the limiting reactant. Since A and B react in a 1:1 mole ratio to form C, the number of moles of C produced is equal to the number of moles of the limiting reactant.
6. Convert the moles of C to grams using the molar mass of C (which is not provided in the question).
For part (b) of the question, the total pressure in the system can be determined using Dalton's Law of Partial Pressures. The total pressure is the sum of the partial pressures of all the gases present in the system. You will need to know the partial pressure of A and B, as well as the mole ratio between A and B.
It's important to note that some key information (such as the molar masses of A, B, and C) is missing from the question. You may need to find or assume these values to proceed with the calculations.
To solve the problem, we need to use the ideal gas law equation and perform various calculations.
a. To find the number of moles for gas A at the given conditions (pressure of 745 torr and temperature of 26°C), we can use the ideal gas law equation:
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.
First, convert the pressure from torr to atm:
1 atm = 760 torr
745 torr / 760 torr/atm = 0.9789 atm
Convert the temperature from Celsius to Kelvin:
T(Kelvin) = T(Celsius) + 273.15
26°C + 273.15 = 299.15 K
Now we can rearrange the ideal gas law equation to solve for the number of moles (n):
n = PV / RT
n = (0.9789 atm) * (V) / [(0.0821 L·atm / mol·K) * (299.15 K)]
Note that the volume (V) is not given. However, since the problem relates to the reaction of A and B in a 1:1 mole ratio, the volume ratio can be used. According to the problem, 10.0 L of A and 8.60 g of B (at STP) are reacted. One mole of any gas occupies 22.4 L at STP, so the volume ratio is:
V(A) / V(B) = 10.0 L / 22.4 L = 0.4464
Substituting this value into the equation, we have:
n = (0.9789 atm) * (0.4464) / [(0.0821 L·atm / mol·K) * (299.15 K)]
Calculate the value of n.
Now, to find the grams of C produced, we need to use the molar mass of A or B. The problem does not provide the molar mass of A, but it does provide the percentage composition of B.
To calculate the molar mass of B, assume you have a 100 g sample, which means it contains:
85.6 g of carbon = (85.6 g C) / (12.01 g/mol) = 7.13 moles of carbon
14.4 g of hydrogen = (14.4 g H) / (1.008 g/mol) = 14.29 moles of hydrogen
The molar mass of B is the sum of the molar masses of carbon and hydrogen:
Molar mass of B = (7.13 moles of carbon) + (14.29 moles of hydrogen)
Calculate the molar mass of B.
Since the problem states that A and B react in a 1:1 mole ratio, the moles of C produced will be equal to the moles of A:
moles of C = moles of A = value of n calculated above
Finally, to find the grams of C produced, multiply the moles of C by the molar mass of C.
b. To find the total pressure in the system when A and B are reacted together, we can use Dalton's law of partial pressures. According to the law, the total pressure is the sum of the partial pressures of the gases:
Total pressure = pressure of A + pressure of B
Given that A is at STP (standard temperature and pressure), its pressure is 1 atm.
To find the pressure of B, we need to determine the moles of B and use it in the ideal gas law equation (PV = nRT) to calculate the pressure. The volume of B is given as 8.60 g, and the molar mass of B is calculated in part a. Divide the mass of B by its molar mass to obtain moles of B. Use this value along with the volume of B and the gas constant (0.0821 L·atm / mol·K) to calculate the pressure of B.
Finally, add the pressure of A to the pressure of B to find the total pressure in the system.