Question

what quantity of ethylen glycol must be added to 125 g of water to raise the boiling point of 1.0 degrees celsuis

Answer 1

Answer:

We should add 15.15 grams of ethylen glycol.

Explanation:

Step 1: Data given

Mass of water = 125 grams

Temperature change = 1.0 °C

The boiling point elevation constant, Kbp, for water is 0.5121 °C/m

Step 2: Calculate mass needed

ΔT = i* Kb *  m

⇒ with i = the van't Hoff factor = 1

⇒ with Kb = 0.5121 °c/ kg/mol

⇒ with m = molality = moles / mass

ΔT = i* Kb *  m  ⇒ 1°C  = 0.5121 °C / kg/mol *   (X/0.125kg)

X = 0.2441 moles

Step 3: Calculate mass of ethylen glycol

Mass ethylen glycol = moles * molar mass

Mass ethylen glycol = 0.2441 moles * 62.068 g/mol

Mass of ethylen glycol = 15.15 grams

We should add 15.15 grams of ethylen glycol.