Flash points are determined experimentally by heating the liquid in a container and then introducing a small flame just above the liquid surface. The temperature at which there is a flash/ignition is recorded as the flash point. Two general methods are called closed-cup and open-cup. The closed-cup method prevents vapors from escaping and therefore usually results in a flash point that is a few degrees lower than in an open cup.
There are two methods for roasting a whole chicken: Regular method: 1  Preheat oven to 350 degrees F (175 degrees C). 2  Roast whole (thawed) chickens for 20 minutes per pound, plus an additional 15 minutes.
Therefore, a 5 lb chicken will need to be roasting in the oven for at least 1h 50 mins. A 5 lb bird will serve between 4 - 5 people. Some people prefer to set the oven temperature to 450ÂºF (230ÂºC) and roast the bird at this high temperature for the first 10 - 15 minutes or the last 10 - 15 minutes. The rest of the time the chicken should be roasted at 375ÂºF (190ÂºC). The surge of heat will result in a really crispy and brown skin and deliciously succulent meat. The table below is a guideline for roasting times for a chicken at 375ÂºF (190ÂºC).