chemistry question?

Question

florine gas exerts a pressure of 975 torr. When the pressure is change to 1.50 atm, its volume is 250ml. what was the original volume?

Answer 1

sorry
I don't know
but please answer us to know
thanks
God " Allah " bless u

Answer 2

First you need to make sure you're dealing with 1 unit of pressure. Let's use atmospheres. Now convert the torrs to atm's by dividing 975 by 760 (since standard temperature-pressure is 760 mmHg). That comes out to about 1.3 and the new unit is 'atm' so it's 1.3 atm.

Now apply Boyle's law, which states that pressure times volume must equal a constant number. So if you increase one, the other must decrease. Mathematically that's: PV = k where k is the constant.

They gave you the volume (250 mL) when the pressure is 1.5 atm. So find out what the constant must be:
PV = k
(1.5atm)*(250mL) = k
375 = k

Remembering Boyle's law, the original volume times the original pressure must also equal this constant. You have the original pressure, which you converted to atm's: 1.3 atm, so substitute that number and the value you found for k into the equation:

PV = k
(1.3atm)*(V) = 375
V = 288.46

The answer is 288.46 mL, but if you need it in sigfigs, then it's 290mL.

Answer 3

Okay well, to answer your question you first need to indicate your givens, so:

p1= 975torr
v1= ?
p2 = 1.50atm
v2 = 250mL = 0.250L

You know that 1 atm = 760torr = 101.325kPa

Therefore convert p1 into kPa so:

975torr/760torr = 1.28 atm

Then multiply by 101.325kPa to get about 130 kPa

so p1 = 130 kPa

p2, you're going to take 1.50 atm and multiply it with 101.325kPa to get: 152 kPa

p2 = 152kPa

Now, you use the equation p1v1 = p2v2

Rearrange:

v1 = (p2v2)/p1
= (152kPa)( 0.250L)/130kPa
= 0.292L or 292mL

Therefore, the original volume is about 292 mL

Hope that helps =]