Question

At high altitudes, the boiling point of water lowers because:
A) Atmospheric pressure is low
B) Temperature is low
C) Atmospheric pressure is high
D) All of the above

Answer 1

For this question to be answered one should know the concept of colligative properties. The colligative property included here is boiling point. When the altitude is increased or at high altitudes the atmosphere becomes drier. At high altitude the level of oxygen gets decreased and the atmospheric pressure also decreases due which the cooking takes time. The moisture evaporated quickly from the substances.

Complete answer:
To boil the water we need to give energy to it in the form of heat. When the eergy get transferred to the water molecules in the form of heat they tend to break their bonds which were holding them together. As we know that now the water will get boil and changes into vapour state when the internal vapour pressure get equals to the pressure exerted on it by the atmosphere. We know that high altitudes have low atmospheric pressure.
As we get high into the atmosphere the pressure of the air will decrease so the boiling point of the water will obviously be at lower temperature because the concentration of oxygen will decrease in air. so now as the water will be boiling at lower temperature at high altitudes so food which will be prepared by boiling will be cooked at lower temperature and the time required to be cooked will be more. In any of the cooking material it is required to heat food to a certain temperature for a certain time length. So if the temperature has been low because of the altitude then cooking time will be extended for cooking.
Hence, the correct option is (A) .

Note: As the altitude increases the atmospheric pressure decreases and the boiling point of water decreases. Now it is important to compensate for the low boiling point of water so time for cooking must be increased. If you will turn up the heat it will not help to cook the food faster. Actually it does not matter how high the cooking temperature is, water will not be exceeding its boiling point unless we use a pressure cooker.