An ideal gas originally at 0.8 atm and 77C was allowed to expand untel its final volume ,pressure and temperature were 600 ml ,0.4 atm and 27C.what was the initial volume

(p1v1/t1) = (p2v2/t2)

t1 and t2 must be in kelvin.

To find the initial volume of the gas, we can use the ideal gas law equation:

PV = nRT

Where:
P = pressure
V = volume
n = number of moles of gas
R = ideal gas constant
T = temperature in Kelvin

First, let's convert the temperatures from Celsius to Kelvin using the equation:

T(K) = T(C) + 273.15

Initial temperature:
T1 = 77°C + 273.15 = 350.15 K

Final temperature:
T2 = 27°C + 273.15 = 300.15 K

Next, we can rearrange the ideal gas law equation to solve for the initial volume:

V1 = (nR * T1) / P1

We have the following values:
P1 = 0.8 atm
T1 = 350.15 K
T2 = 300.15 K
P2 = 0.4 atm
V2 = 600 ml

Since the number of moles (n) and the gas constant (R) are not provided, we can assume that they cancel each other out when comparing the ratios of pressure and volume. Therefore, we can use the ratio of the initial and final states:

(P1 * V1) / T1 = (P2 * V2) / T2

Now let's plug in the values we know:

(0.8 atm * V1) / 350.15 K = (0.4 atm * 600 ml) / 300.15 K

Simplifying the equation:

0.8 * V1 = 0.8 * 600 ml

We can cancel out the common factors:

V1 = 600 ml

Therefore, the initial volume of the gas is 600 ml.