The stopcock connecting a 4.87 l bulb containing hydrogen gas at a pressure of 4.38 atm, and a 4.87 l bulb containing argon gas at a pressure of 2.90 atm, is opened and the gases are allowed to mix. assuming that the temperature remains constant, the final pressure in the system is

P = 3,63 atm

Explanation:

Using PV=nRT and knowing the temperature in the problem remains constant it is possible to rewrite this formula, thus:

PV = kn, where k is RT (Constant), P is pressure, V is volume and n are moles.

The first bulb contains:

4,87L×4,38atm = 21,3k moles

And the second bulb:

4,87L×2,90atm = 14,1k moles

When gases are mixed, the total moles are:

21,3k moles + 14,1k moles = 35,4k moles

As total volume is 4,87L + 4,87L = 9,74L

Replacing:

P = kn/V

P = 35,4k moles / 9,74L

P = 3,63 atm

I hope it helps!

Explanation:

To convert from grams to moles, we must use the molar mass. This number can be found on the Periodic Table.

We can use number as a ratio.

Multiply by the given number of grams.

Flip the fraction so the grams of silicon cancel.

The original number of grams (78.0) has 3 significant figures, so our answer must have the same. For the number of moles calculated, that is the hundredth place. The 7 in the thousandth place tells us to round the 7 to a 8.

There are about 2.78 moles of silicon in 78.0 grams.