I need a formula for Chemistry?

Question

A 125.0 mL sample of nitrogen at 790 torr was compressed to a volume of 75.0 mL in a syringe. What was the pressure of trapped nitrogen in torr?

can someone give me the formula so I can figure this out???

Can someone take me through the formula steps please!!!...I am horrible at chem.

Answer 1

its boyle's law..
Boyle's Law states the product of the volume and pressure of a fixed quantity of an ideal gas is constant, given constant temperature.

so it is mathematically,
PV= k
k is a constant.
it means pressure and volume of a fixed mass of a gas vary inversely.
so if the pressure increases , volume decreases..
conversely, if pressure decreases , volume increases..
now u can expand this equation so that it suits your need..

so now u can write it as,
P1V1 = P2V2 = k
where P1 and V1 are pressure and volume initially,
P2 and V2 are pressure and volume at the next instance
using this formula u can solve ur problem,

P1=790torr, V1 = 125ml P2= ? , V2= 75 ml
so , 790*125 = P2 * 75
P2 = 790*125/75


hence,P2=1316.66torr




for any such problems u can use a general formula ,
the ideal gas equation,

PV / T = k or P1V1 / T1 = P2V2 / T2 = k

Answer 2

V1P1 = V2P2 where V= volume and P = pressure
V1= 125 ml
P1 = 790 torr
V2 = 75 ml
P2 = ?

to manipulate the equation,
P2= (V1)(P1)/V2
= (125ml)(790 torr)/(75 ml)
= 1317 torr

Answer 3

c.f. Boyle's Law
Assuming Ideal Gas conditions and allowing the sample to return to original temperature:

790*(125/75)

Answer 4

(P1)(V1) = (P2)(V2); if the temperature is constant.
P2 = 790 * 125.0/75.0

Answer 5

P1V1 = P2V2

P1V1/V2 = P2