how many molecules are there in a 4.5L at 27 C and 700 torr?

Answer 1

Use ideal gas law to calculate this answer.

PV = nRT

P = 700 torr
V = 4.5 L
n = number of moles of gas
R = 62.36 L*torr/mol*K
T = 300 K (27 C + 273 = 300 K)

(700)(4.5) = (n)(62.36)(300)

3150 = (n)(18708)

3150 / 18708 = n = 0.168 mol gas

(0.168 mol)(6.02 x 10^23) = molecules of gas

= 1.01 x 10^23 molecules of gas present

Answer 2

There are Avogadro's number, 6.02x10E23 molecules in 22.4 liters at STP (0 celsius and 760 torr).

P1V1/T1 = P2V2/T2

Your data is V1 = 4.5L
P1 = 700 torr
T1 = 300K

P2 = 760 torr.
T2 = 273K

Solve for V2 then divide by 22.4. Now multiply by Avogadro and you're done

Answer 3

use the ideal gas law, PV=nRT. you would covert the 700 torr into atm and add 273 to the 27 c to get K. and you know r because its a constant, just plug in what you know to solve for n. thats how many moles you have, and you know that avogadro number is how many molecules per 1 mole of something. so multiply your number of moles by avogadros number to get your answer.