Question

8. When a 2.5 mol of sugar (C12H22O11) are added to a certain amount of water the boiling point is raised by 1 Celsius degree. If 2.5 mol of aluminum nitrate is added to the same amount of water, by how much will the boiling point be changed? Show all calculations leading to your answer OR use 3 – 4 sentences to explain your answer.

9. If 5.40 kcal of heat is added to 1.00 kg of water at 100⁰C, how much steam at 100⁰C is produced? Show all calculations leading to an answer.

Answer 1

Hey there!:

8) ΔTb = i*Kb*m

m is molality

Since same number of mol is added to same amount of water in both cases

m will be same for both

is 1 for glucose since it is covalent compound

is 4 of Al(NO3)3 as it breaks into 1 Al₃⁺ and 3 NO₃⁻

So, ΔTb will be 4 times in aluminum nitrate case

So, boiling point will change by 4ºC

9) use Q = m* L

L = heat of vaporization so:

T1=T2=100ºC

5.40 * 1000 => 5400 cal/g

Q = 5400 / 540

Q = 10 grams

Hope that thlps!