A certain amount of gas has a volume of 4000cm^3 at a temperature of 27 degree celsius and a pressure of 1.2 atmospheres. If the pressure is kept constant, find the volume of the gas if it is heated to 60 degree celsius.

Please tell me what formula should I use.

To solve this problem, we can use Charles's Law, which states that for a given amount of gas at constant pressure, the volume of the gas is directly proportional to its temperature.

The formula for Charles's Law is:
V₁/T₁ = V₂/T₂

Where:
V₁ = Initial volume of the gas (4000 cm³)
T₁ = Initial temperature of the gas (27°C + 273.15 = 300.15 K)
V₂ = Final volume of the gas (to be determined)
T₂ = Final temperature of the gas (60°C + 273.15 = 333.15 K)

To find the final volume of the gas (V₂), plug in the given values into the formula and solve for V₂:

V₁/T₁ = V₂/T₂
4000 cm³ / 300.15 K = V₂ / 333.15 K

Cross-multiplying gives us:
V₂ = (4000 cm³ * 333.15 K) / 300.15 K
V₂ ≈ 4430.56 cm³

Therefore, the volume of the gas when heated to 60°C is approximately 4430.56 cm³.