12/11 & 12/12 - 8th Grade Agenda

Learning Objective: Learn about Fire SafetyCollect HW: Reading & Notetaking: p.124 – 125Exothermic & Endothermic reaction labTextbook Reading p. 258-263HW: Reading & Notetaking p.126 – 128Reminder HW: Science Fair Background due 1/13 & 1/14 (10 Points)

Daily Reflection

• Prompt: What is the difference between a solution and a suspension?

Solution vs SuspensionWhat is a mixture in which

particles can be seen and easily separated by settling or

filtration?• Suspension• Chalk and water• when we mix substances they stay in

clusters

Solution vs SuspensionWhat is a well mixed mixture?

• Solution• Salt and water • If you taste a salt

solution, any sip tastes just as salty as the next.

Solvent vs SoluteThe part of the solution present in the largest amount is called…

• Solvent

• In Salt water which part is the solvent?

• Water

Solvent vs SoluteA substance present in a

solution in a smaller amount is called…

• Solute

• In Salt water which part is the solvent?

• Salt

Something we drink is also known as the “universal solvent”• Water

• Why?

• Because it dissolves so many substances.

• Water solutions are essential in the living world

What two factors affect the solubility of a substance?

• Temperature• Type of solvent• Most solids become

more soluble as the temperature goes up

• Most gases becomes less soluble as the temperature goes up

What is a solution?

• In a solution, particles are uniformly distributed and too small to scatter light.

What is a colloid?

• A Colloid is a mixture that contains small undissolved particles that do not settle out.

What is a Suspension?

• A suspension is a mixture in which particles can be seen and easily separated by settling or filtration.

How can you test this is sugar water or salt water without drinking it?

• You can test the electrical conductivity of the solution.

• If no ions are present (as in a sugar solution), current wil not flow.

Why do they use salt to melt ice on the road?

• Freezing point of water will be lowered.

• It’s also how they make ice cream

• In general Solutes lower the freezing point of solvent

What happens to the boiling point of water when you add salt

to it?• boiling point of water will

be raised.• That’s why cooks add salt

to boiling water before adding the spaghetti

• In general solutes raises the boiling point of solvent

Why does solutes lower freezing and raise boiling point?

• Solute particles interfere with the change of state

What is Solubility?

• Solubility is a measure of how much solute can dissolve in a solvent at a given temperature

What is unsaturated solution?

• If you can continue to dissolve more solute, it is a unsaturated solution

What is unsaturated solution?

• When you’ve added so much solute that no more dissolves, you have a saturated solution.

What are the factors that affect the solubility of a substance?

• Pressure• Temperature• Type of Solvent

Higher Pressure can increase the solubility of gases

• Opening a can of soda reduces pressure and carbon dioxide escapes.

• Scuba divers need to come up from a deep dive slowly or nitrogen bubble form in the blood stream (The Bends)

Hydrophobic – Hydrophilic Demo

• Hydrophobic: Hates Water

• Hydrophilic: Loves Water

• Polymer: A large, complex , carbon-based molecule built from smaller molecules joined together.

Prediction:

• What will happen to the Polymer Snow if we add salt to it?