You are a chemical developer for a major automotive parts supplier that develops

Question

You are a chemical developer for a major automotive parts supplier that develops antifreeze designed specifically for their vehicles. Antifreeze lowers the freezing point of water relative to pure water. This is an example of the colligative property of freezing point depression. In the presence of antifreeze, the freezing point of water – which serves as a coolant in internal combustion engines – will be lowered, thus preventing potentially catastrophic damage to the engine that would otherwise occur upon expansion of water due to freezing.

Despite its name, anti-freeze also plays an important role in keeping your engine working during the summer months: the anti-freeze also acts to elevate the boiling point of the water so that it doesn’t start to boil on really hot days. Your boss is considering using a calcium chloride solution as anti-freeze and wants you to study the impact of the new anti-freeze on boiling.

Q1)In the lab you used an ice bath to study the freezing point of your solution. To confirm the boiling point elevation you calculated, you will need to heat up your solution. Describe how you can adapt your lab set-up to get the water and solutions up to the boiling point.

Q2)In your boiling point elevation measurement, describe all the temperature measurements you need to make to determine Tb (the change in boiling point), including what observation will indicate the boiling point has been reached

Please help

Thank you .

Explanation / Answer

Depression in freezing point and elevation in boiling point

A solution od calcium chloride in water is used to estimate elevation in boiling point

1) The bath with the flask containing the aqueous solution of calcium chloride is heated. The difference in temperature final - initial of solution gives us the value for the elevation of boiling point of the given solution.

2) To reach boiling point, start heating the solution slowly. Note down the tmperature change after every minute. After certian time the temperature becomes constant and no more rises. Take another 3-4 readings. This is the boiling point of the solution. The vapor pressure of solution becomes equal to the atmospheric pressure at the boiling point of the solution of calcium chloride.

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