In: Chemistry
1. A substance will boil at lower temperature if:
A. The volume of the system is deceased.
B. The presence of the system is deceased.
C. An additional amount of the substance is added.
D. The substance is dissolved in water.
E. A and B
2. Food will cook quickly for canning when salt is added to the water. True or False
Q1.
Correct answer: B,
Explanation: if the pressure of a system is decreased then boiling
point decreases becuase its vapor pressure easily overcome the
external lower pressure. For example, at the height such as
mountains, cooking food is difficult because due to lower pressure
at the height, the boiling point of the water decreases.
therefore, if external pressure is decreased then the boiling point
will increase.
options C, D are wrong because addition of extra substance cause an
increase in its boiling point while volume does not affect boiling
point.
Q2. Answer: True,
Explanation: if salt is added to the water then boiling point of water increases which makes water to absorb more heat in order to boil. If water is absorbing more heat, food grains will also get more heat and hence cooking will be done quickly.