Use the following information to identify element A and

compound B, then answer questions a and b.

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ｰC. When the container is evacuated and refilled

with a certain element (A) at a pressure of 745 torr

and a temperature of 26ｰ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 (10.68 L) with excess

oxygen gas. The vessel is placed in a constant-temperature

bath at 22ｰ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 desiccant. Ascarite is asbestos impregnated

with sodium hydroxide; it quantitatively absorbs

carbon dioxide:

2NaOH(s) CO2(g) 88n Na2CO3(s) H2O(l)

The desiccant is anhydrous magnesium perchlorate,

which quantitatively absorbs 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 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 steel 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 gas C.

a. How many grams of C will be produced if 10.0 L

of A and 8.60 L 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?Sara--I worked on this problem but didn't complete it. Perhaps what I have you have already done.

The difference in mass of the empty container and the container filled with N2 will give you the mass of the N2 added. From that you can calculate moles N2, then use PV = nRT to calculate the volume of the container. The second filling with the gaseous element, A, gives you a mass of element A when subtracted from the mass of the empty container. Again, use PV=nRT to calculate n; then using n and grams, calculate the molar mass (I found about 71). This element probably is Cl2 but there is no other information to prove that. However, we know there are no monatomic atoms that are gases with an atomic mass of 71 and Cl2 is about the only one close to 71 for a diatomic gas. Then element B gives %C and %H which allows you to calulate the simplest empirical formula. I found that to be CH2. There is no hydrocarbon molecule that is CH2; therefore, I assume this must be a dimer or so of CH2 (for example, ethene or propene) but I did not see the data to support that. This may be a "made up" problem. Anyway, perhaps this will get you started. I hope this helps a little. the container that is filled with nitrogen gas is at a temperature of 14C not 15 you should tray that and see if it works.

compound B, then answer questions a and b.

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ｰC. When the container is evacuated and refilled

with a certain element (A) at a pressure of 745 torr

and a temperature of 26ｰ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 (10.68 L) with excess

oxygen gas. The vessel is placed in a constant-temperature

bath at 22ｰ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 desiccant. Ascarite is asbestos impregnated

with sodium hydroxide; it quantitatively absorbs

carbon dioxide:

2NaOH(s) CO2(g) 88n Na2CO3(s) H2O(l)

The desiccant is anhydrous magnesium perchlorate,

which quantitatively absorbs 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 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 steel 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 gas C.

a. How many grams of C will be produced if 10.0 L

of A and 8.60 L 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?Sara--I worked on this problem but didn't complete it. Perhaps what I have you have already done.

The difference in mass of the empty container and the container filled with N2 will give you the mass of the N2 added. From that you can calculate moles N2, then use PV = nRT to calculate the volume of the container. The second filling with the gaseous element, A, gives you a mass of element A when subtracted from the mass of the empty container. Again, use PV=nRT to calculate n; then using n and grams, calculate the molar mass (I found about 71). This element probably is Cl2 but there is no other information to prove that. However, we know there are no monatomic atoms that are gases with an atomic mass of 71 and Cl2 is about the only one close to 71 for a diatomic gas. Then element B gives %C and %H which allows you to calulate the simplest empirical formula. I found that to be CH2. There is no hydrocarbon molecule that is CH2; therefore, I assume this must be a dimer or so of CH2 (for example, ethene or propene) but I did not see the data to support that. This may be a "made up" problem. Anyway, perhaps this will get you started. I hope this helps a little. the container that is filled with nitrogen gas is at a temperature of 14C not 15 you should tray that and see if it works.

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