1. Chapter 7 – Acids, Bases and Solutions

2. Chapter 7 – Acids, Bases and Solutions
Section 1 – Understanding Solutions
Standards
5.d – Students know physical processes including freezing and boiling, in which a material changes form with no chemical reaction

3. What is a Solution?
Solution – a uniform mixture that contains a solvent and at least one solute
Solvent – the part of a solution present in the largest amount (dissolves the other substances)
Solute – the substance that is present in a solution in a smaller amount and is dissolved by the solvent

4. A solution has the same properties throughout
A solution has the same properties throughout. It contains solute particles (molecules or ions) that are too small to see.
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5. Examples of solutions/solvents:
Hot chocolate – solute = chocolate, sugar
solvent –milk
Lemonade – solute = lemon juice, sugar
solvent – water
Soda – solute = carbon dioxide, sugar
The universal solvent – WATER!!!

6. Chapter 7 – Acids, Bases and Solutions
Section 3 – Describing Acids and Bases
Standards
5.e – Students know how to determine whether a solution is acidic, basic or neutral

7. Properties of Acids
Acids – something that tastes sour, reacts with metals and carbonates and turns blue litmus paper red

8. Examples of Acids
Ex: lemon juice, soda, coffee, battery acid, tomatoes, stomach acid, HCl, vinegar

9. Properties of Bases
Bases – something that tastes bitter, feels slippery and turns red litmus paper blue

10. Examples of Bases
Examples: drain cleaners, antacids, bleach, baking soda, oven cleaner, shampoo, soap, toothpaste

11. Chapter 7 – Acids, Bases and Solutions
Section 4 – Acids and Bases in Solution
Standards
5.e – Students know how to determine whether a solution is acidic, basic or neutral

12. Acids in Solution
Hydrogen Ion (H+) – an atom of hydrogen that has lost its electron
An acid produces hydrogen ions in water

13. Bases in Solution
Hydroxide Ion (OH-) – a negative ion made of hydrogen and oxygen
A base produces hydroxide ions in water

14. Strength of Acids and Bases
Knowing the concentration of hydrogen ions is the key to knowing how acidic or basic a solution is – scientists use a pH scale
pH Scale – range of values from 0-14 used to express the concentration of hydrogen ions in a solution

15. Strength of Acids and Bases
Neutral Solution – a solution that is neither acidic nor basic…has a pH of 7
A pH of less than 7 is acidic. The closer to 0, the stronger the acid, and the more H+ ions produced.
A pH of more than 7 is basic. The closer to 14, the stronger the base, and the more OH- ions produced.

16. Acid-Base Reactions
Neutralization – reaction between an acid and a base
In a neutralization reaction, an acid react with a base to produce salt and water
Ex: HCl + MgOH  H2O + MgCl