The temperature of a 4.5-liter helium gas is raised to 80oC. The volume increased to 9.0 liters. What is the initial temperature of the gas in oC?

Initial temperature = T₁ = -96.65 °C

Explanation:

Given data:

Initial volume = 4.5 L

Final temperature = 80°C (80+273 = 353 K)

Final volume = 9.0 L

Initial temperature = ?

Solution:

According to  Charles law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.

Mathematical expression:

V₁/T₁ = V₂/T₂

V₁ = Initial volume

T₁ = Initial temperature

V₂ = Final volume  

T₂ = Final temperature

Now we will put the values in formula.

V₁/T₁ = V₂/T₂

T₁  = V₁ T₂/V₂

T₁  = 4.5 L × 353 K / 9.0 L

T₁  = 1588.5 L.K / 9.0 L

T₁  = 176.5 K

Kelvin to °C:

176.5 K - 273.15 = -96.65 °C

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

i'm pretty sure its b i might be wrong though!