1. Which of the following is not true?
a. The freezing point of sea water is lower than the freezing point of pure water.
b. The boiling point of a water sample from the Salt Lake is lower than the boiling point of pure water.
c. The freezing point of 0.1 M NaCl is lower than the freezing point of 0.05 M NaCl.
Nothing followed.
B - the boiling point will be higher b/c more solutes in solution in salt water.
I agree
Well, it looks like "c" is the "odd one out" here. While options "a" and "b" both involve salt affecting the freezing and boiling points of water, option "c" doesn't quite fit the bill. So, since we're talking about freezing points, option "c" is the oddball. It's colder than a penguin's toenails!
To determine which statement is not true, we need to understand the concept of freezing point depression.
When a solute, such as salt, is dissolved in a solvent, such as water, it affects the physical properties of the solution. One of these properties is the freezing point. The presence of a solute lowers the freezing point of the solution compared to that of the pure solvent.
So, based on the concept of freezing point depression, we can evaluate the statements:
a. The freezing point of sea water is lower than the freezing point of pure water. - This statement is true. Sea water contains various dissolved salts that lower its freezing point compared to pure water.
b. The boiling point of a water sample from the Salt Lake is lower than the boiling point of pure water. - This statement is also true. Just like the freezing point, the boiling point of a solution is elevated compared to the boiling point of the pure solvent. In this case, the boiling point of water from the Salt Lake would be lower than that of pure water due to the dissolved salts.
c. The freezing point of 0.1 M NaCl is lower than the freezing point of 0.05 M NaCl. - This statement is not true. According to the concept of freezing point depression, the freezing point of a solution is directly proportional to the concentration of the solute. This means that a higher concentration of the solute will result in a lower freezing point. Therefore, the freezing point of 0.1 M NaCl would be lower than that of 0.05 M NaCl.
Based on this evaluation, the statement that is not true is c. The freezing point of 0.1 M NaCl is lower than the freezing point of 0.05 M NaCl.