Question

Use the following information to identify element A and come
pound 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°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 (10.68 L) with excess oxygen gas. The vessel is
placed in a constant-temperature bath at 22°C. The pressure in
the vessel is 1 1.98 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) -----> 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 carefdly 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 10.0 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?
How do i get the answer to parts a and b

Answer 1

If you haven't identified compounds A and B, do that, then you can answer part a and b.

Answer 2

no i did identify compounds A and B i just do not understand how to do part a

Answer 3

I got that A was Cl2 and B was CH2 but i do not understand how to get the grams of C produced, i am confused at this point.

Answer 4

Actually, the empirical formuls for B is CH2. The compound (the molecular formula is twice the empirical formula in this case) is C2H4 or ethene (ethylene).
C2H4 + Cl2 ==> Cl-CH2-CH2-Cl is compound C.
You can change liters to mols remembering that 22.4 L is the volume occupied by a mole at STP, BUT, you can use a shortcut and just use liters since all gases are involved. (The trick is you divide by 22.4 to change to mols, calculate moles products, then convert back to volume by multiplying by 22.4. So you just cut out the 22.4 step (both of them) and use liters instead.
10 L of A react with 8.6 liters B means B is the limiting reagent so 8.6 liters C will be produced. Change 8.6 L C to grams from the formula I wrote above.
Now that you have the formula for C and its molar mass and grams, part (b) should be easier for you.