Chemistry P3 - Topic 3, 4

What is the difference between a heterogenous and homogenous mixture?

Heterogenous you’re able to see physical parts of the mixture, homogenous it look as if it is one mixture.

What is it called when water bonds to itself and why?

When water bonds to itself, it is called cohesion. This happens because the solution is polar in which one end is more positive then the other.

What are the properties of water?

• Cohesive

• High boiling and freezing point - Strong hydrogen bonding needs lot of heat to change state of matter

• Solid water floats on liquid water(Ice floats in water) - The density of ice is lower than the density of water

What is the difference between a solute and a solvent

The solvent is what dissolves the solute, while the solute is what is dissolving

Ex)When putting ice tea powder in water, the water is the solvent and the ice tea powder is the solute

Define concentration

How much solute is dissolved in a solution

What is it called when solutions have a high or low concentration

Low concentration is called diluted while high concentration is called concentrated

Can molecular compounds dissolve?

Some molecular compounds dissolve, but don’t dissolve into electrolytes in water. Molecular compounds that don’t dissolve create heterogenous mixtures.

What are solutions called when they are made out of molecular compounds?

They are called non electrolytes and cannot conduct electricity.

Define dissociation

When the bonds of an ionic compound dissolves into smaller parts; dissolving

Define electrolye

A solution able to conduct electricity

Properties of acids

• Molecular

• Contains hydrogen + element/polyatomic

• Dissociates = forms ions

• electrolyte

• Always aqueos(aq)

• Sour, corrosive

• Ex) HBr

• Litmus paper = red

• Bromothymol blue = yellow

• Phenolphthalein = colorless

Properties of bases

• Ionic

• Contains metal + OH → hydroxide

• Dissociates = forms ions

• Electrolyte

• Always aqueos(aq)

• Bitter, slippery

• Ex) Al(OH)3

• Litmus paper = blue

• Bromothymol blue = blue

• Phenolphthalein = pink

What is a pH and what does it tell you

It is a logarithmic scale that tells you how acidic something is

The concentration of acid and bases change by how much?

10 times

When the pH number increases, the concentration of acid __?

decreases by 10, the higher the number, the lower the acidity. The hydrogen ion concentration determines the pH

On the pH scale, what numbers represents acidic, neutral, and basic?

• Acidic is less than 7

• Neutral is 7

• Base is more than 7

What are some evidence that a chemical reaction is occurring?

• Formation of gas

• Heating/cooling

• Smell

• Color change

• light

• 2 aq solutions forming a solid

The difference between endothermic and exothermic

• Endothermic absorbs heat and energy and is cold, ex) ice packs

• exothermic releases heat and is hot, ex)hand warmers

What is the collision reaction theory?

A theory in which chemical reactants must collide to break bonds and make new products

What are 3 things that are conserved(stay the same) during a chemical reaction?

1. mass

2. energy

3. types of atoms

Total mass of reactants is equal to?

total mass of the product