Docsity
Log inSign up
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search Store documents

The best documents sold by students who completed their studies

Search through all study resources
Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

University Rankings

Discover the best universities in your country according to Docsity users

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

From our blog

Exams and Study
Go to the blog

Colligative Properties: Understanding the Impact of Solutes on Freezing and Boiling Points, Study notes of Chemistry

Delaware College of Art and Design (DCAD)Chemistry

The concept of colligative properties, focusing on how the presence of solutes affects the freezing and boiling points of solutions. Topics include particle arrangement during freezing and boiling, the effect of salt on the freezing and boiling points, and the relationship between concentration, dissociation, and colligative properties. The document also covers the van hoff factor and provides formulas for calculating freezing point depression and boiling point elevation.

What you will learn

  • How does the presence of a solute affect the freezing point of a solution?
  • How does the van Hoff factor relate to the number of particles a solute dissociates into in solution?
  • Why does the boiling point of a solution increase when a solute is added?

Typology: Study notes

2021/2022

Uploaded on 09/12/2022

anarghya
anarghya 🇺🇸

4.2

(21)

255 documents

1 / 4

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
ColligativeProperties2018.notebook
1
April09,2018
Mar114:12PM
Colligative Properties
Aim: To observe and explain the affect that a solute has on
colligative properties (freezing and boiling points)
Mar114:18PM
DO NOW
•
Why do you put salt in water when cooking pasta?
•
Why do you put rock salt down on the roads when its icy?
Mar114:18PM
DEMO‐ Boiling Point of Water
Mar114:18PM
COLLIGATIVE PROPERTIES AND
FREEZING POINT
•
Intermsofparticlearrangement,explainwhatoccurswhenasubstancesfreezes .
•
Howisthepresenceofsaltmoleculesaffectingthefreezingprocessofwater?
•
Whatwillthisdototheamountofenergythatmustbelosttofreezethewater?
•
Howwillthesaltaffectthefreezingpointofwater?
•
Theparticlesmoveclosertogetherastheyfreeze.
•
Thesaltmoleculesareblockingthewatermoleculesfromfreezingtogether.
•
Thisincreasestheamountofpotentialenergythatmustbelosttofreeze.
•
Thefreezingpointdecreases.
pf3
pf4

Partial preview of the text

Download Colligative Properties: Understanding the Impact of Solutes on Freezing and Boiling Points and more Study notes Chemistry in PDF only on Docsity!

Mar 114:12 PM

Colligative Properties

Aim: To observe and explain the affect that a solute has on colligative properties (freezing and boiling points) Mar 114:18 PM

DO NOW

  • Why do you put salt in water when cooking pasta?
  • Why^ do^ you^ put^ rock^ salt^ down^ on^ the^ roads^ when^ its^ icy? Mar 114:18 PM

DEMO‐ Boiling Point of Water

Mar 114:18 PM

COLLIGATIVE PROPERTIES AND

FREEZING POINT

  • In terms of particle arrangement, explain what occurs when a substances freezes.
  • How^ is^ the^ presence^ of^ salt^ molecules^ affecting^ the^ freezing^ process^ of^ water?
  • What will this do to the amount of energy that must be lost to freeze the water?
  • How will the salt affect the freezing point of water?
    • The particles move closer together as they freeze.
  • The salt molecules are blocking the water molecules from freezing together.
  • This^ increases^ the^ amount^ of^ potential^ energy^ that^ must^ be^ lost^ to^ freeze.
  • The freezing point decreases.

Mar 114:18 PM

COLLIGATIVE PROPERTIES AND

BOILING POINT

  • In terms of particle arrangement, explain what occurs when a substance boils.
  • How are the presence of salt molecules affecting the boiling process of water?
  • What will this do to the amount of energy that is required to boil the water?
  • What will the requirement for more energy do to the boiling point?
    • The^ particles^ move^ farther^ apart^ as^ they^ vaporize.
  • The salt molecules are blocking the water molecules from boiling and escaping
  • This^ increases^ the^ amount^ of^ potential^ energy^ that^ must^ be^ absorbed^ to^ boil
  • The boiling point increases. Mar 114:18 PM

Concentration, Dissocation and

Colligative Properties

  • According to the diagrams above, which compound dissociates into ions?
  • Complete the dissolving equations for the compounds below. If dissociation occurs, write the individual ions and their charges. C 6 H 12 O 6 (aq) ‡ NaCl (aq) ‡ - Sodium chloride C 6 H 12 O 6 (aq) Na+^ (aq) + Cl‐^ (aq) NO DISSOCIATION; Covalent bonds Mar 114:18 PM

Concentration, Dissocation and

Colligative Properties

Which of these compounds would cause a greater change in the boiling point or freezing point of a substance, 1 M NaCl or 1 M C 6 H 12 O 6? Explain your answer in terms of particle quantities and concentrations. (Hint: Think about dissociation) The 1 M NaCl solution because it dissociates into ions and yields more particles in solution to cause more interference with the water boiling or freezing. Feb 2210:18 AM

What affects colligative properties?

The addition of any solute to a solution will increase the boiling point and decrease the freezing point. This is because the solute particles block the water molecules from escaping as a gas when boiling and from moving together to form a solid when freezing. As a result additional energy is required to boil (higher BP) and additional energy must be lost to freeze (lower FP).

Feb 2312:34 PM

Freezing Point Depression

  1. What is the freezing point depression of an aqueous solution of 10.0 g of sodium chloride (NaCl) in 50.0 g H 2 O? ∆T =? i = 2 (Na+^ + Cl‐ ) m = molality=3.42 m Kf=1.86°C/ m ∆T = i m Kf m = moles of solute = 0.171 mol kg of solvent 0.05 kg 10.0 g x 1 mol = 0.171 mol 58.5 g NaCl

∆T = (2)(3.42)(1.86)= 12.72°C

The solutions freezing point is lowered to ‐12.72 °C. Feb 2312:34 PM

Boiling Point Elevation

  1. What is the boiling point of a 1.50 m aqueous NaCl solution? ∆T =? i = 2 (Na+^ + Cl‐ ) m = molality=1.50 m Kf=0.51°C/ m ∆T = i m Kb ∆T = (2)(1.50)(0.51)= 1.53°C The solutions boiling point is elevated 101.53 °C. Feb 237:27 PM
  2. What is the boiling point of a solution that contains 1.25 mol CaCl 2 in 1400 g of water?

Boiling Point Elevation

∆T =?

i = 3 (Ca+2^ + 2 Cl‐ ) m = molality= 0.89 m Kf=0.51°C/ m ∆T = i m Kb ∆T = (3)(0.89)(0.51)= 1.36°C The solutions boiling point is elevated 101.36 °C. m = moles of solute = 1.25 mol kg of solvent 1.4 kg