Final answer:
A flammable refrigerant can only burn or explode if its concentration is above the lower explosive limit and below the upper explosive limit. The warning to store the refrigerant below 120°F is to prevent the can from rupturing or exploding due to increased pressure at higher temperatures. The new pressure of a can if temperature rises from 24°C to 50°C can be calculated using the ideal gas law.
Step-by-step explanation:
A flammable refrigerant can only burn or explode if the refrigerant concentration is above the lower explosive limit (LEL) and below the upper explosive limit (UEL). So the correct option from the given choices would be d. Equal to the lower explosive limit. The reason for this is because the flammable refrigerant concentration between the LEL and UEL has the right proportion of refrigerant vapor to air, which supports combustion if an ignition source is present.
The warning to store the can at temperatures below 120°F (48.8°C) and not to incinerate is there because elevated temperatures can increase the pressure within the can, leading to a risk of rupture or explosion. Using the ideal gas law to calculate the effects of increased temperature, one can determine how pressure changes. For example, a gas in a can initially at 24°C and 360 kPa would experience an increase in pressure if left in a car that reaches 50°C.
To calculate the new pressure if the temperature rises to 50°C, we can rearrange the ideal gas law to P2 = P1(T2/T1), where P1 is the initial pressure, T1 is the initial temperature in Kelvin, and T2 is the final temperature in Kelvin. First, convert the temperatures to Kelvin (297K to 323K), making the new pressure P2 = 360 kPa (323K / 297K) = 390.9 kPa.