Notes Science SPI 0807.9.12 Acids and Bases SPI 0807.9.12.B Bases Learning Intention: Identify the basic properties of bases. Purpose: to understand that many common substances contain bases Success Criteria I will show that I understand this topic by earning a 90 or higher on the quiz. I Can Statement By the end of this unit I will be able to say... ...I can describe three or more properties of bases

…used in soaps and detergents Bases…what are they? A compound that increases negative hydroxide ions in water Have a bitter flavor, feels slippery, and conducts electricity Bases neutralize acids and acids neutralize bases Common in everyday life (used in soaps and detergents) Common in everyday life: for stomach aches and heartburn …used in soaps and detergents …used in acid reducers (called antacids)

Other Common Uses of Bases Drain Cleaners Oven Cleaners Batteries Toothpaste Ammonia

Bases Quick Review SPI 0807.9.12 Acids and Bases Fill in the blanks using the following words… slippery, hydroxide, bases, oven cleaners, compound, bitter 1) A base is a ___________that increases the number of _____________ions. 2) Bases have a ______ flavor 3) _________ neutralize acids. 4) Bases feel __________ . 5) Bases are found in _____________, batteries, antacids, drain cleaners, and tooth paste. compound hydroxide bitter Bases slippery oven cleaners

The pH Scale pH scale: measures acidity or basicity (A.K.A. Alkalinity) (tells you how strong or weak an acid or base is) Bases are 7.1 to 14 on the pH Scale 7 is neutral (pure water is 7) Bases are 7.1 to 14

Memory Trick Think of letter B. B for bases. Again…bases are 7.1 to 14 on the pH scale. With bases, the higher the number…the stronger the base. Example: a base with pH 14 is stronger than a base with pH 10 Memory Trick Think of letter B. B for bases. B for blue on litmus strips. B for Bigger numbers. On the pH scale, bases are the bigger numbers (7.1 to 14). pH 14 is stronger than pH 10

The pH Scale can be displayed four different ways Ex: Vertical -0 at top and 14 at bottom Ex: Vertical -14 at top and 0 at bottom Ex: Horizontal -0 on the left with 14 on the right Ex: Horizontal -14 on the left with 0 on the right pH Scale Yet the pH ranges stay the same. pH Scale (0 to 6.9 for acids and 7.1 to 14 for bases) pH Scale pH Scale

Fill in the blanks using the following words Quick Review SPI 0807.9.12 Acids and Bases Bases Fill in the blanks using the following words higher, 7.1 to 14, alkalinity, strength, pH 13 1) Which base is stronger, pH 13 or pH 8? ____________. 2) The pH scale tells you the __________ of acids and bases. 3) A synonym for basicity is _________________ . 4) With acids the lower number is stronger. Yet with bases the _________ number is stronger. 5) The pH range for bases is _________. pH 13 strength alkalinity higher 7.1 to 14

Bases Change Colors in Indicators Examples of Indicators: litmus paper cabbage juice phenolphthalein bromothymol blue

More About Bases and Indicators Bases turn Red litmus paper Blue. One common indicator is litmus paper (see picture below) Bases turn Red litmus paper Blue. Memory Trick: B for Blue goes with B for Base

More About Bases and Indicators Memory Trick: B for Blue goes with B for Base

Fill in the blanks using the following words… Quick Review SPI 0807.9.12 Acids and Bases Bases Fill in the blanks using the following words… blue, phenolphthalein, Indicators, No, acids 1) ___________ change color in acids or bases. 2) Bases turn red litmus paper ______. ________ turn blue litmus paper red. 4) Is litmus paper the only kind of indicator (yes or no?) ______ 5) Cabbage juice, bromothymol, and _________________ are other acid-base indicators. Indicators blue Acids No phenolphthalein

What is wrong with answer-choice A? Bases are common in everyday life (used in soaps and detergents) SPI 0807.9.12 Acids and Bases Science Questions What is wrong with answer-choice A? Letter D Base

Bases turn Red litmus paper Blue. Bases conduct electric current: found in alkaline batteries What’s wrong with letter B? Acids release hydrogen gas when they react with metals. Base do not react with metals.

What’s wrong with letter A? Uses of Bases Bases are 7.1 to 14 on the pH Scale Oven Cleaners Drain Cleaners What’s wrong with letter A? Bases do conduct electricity. Bases are in alkaline batteries.

What’s wrong with letter B? Bases are the bigger numbers! It has a strong likely pH of this cleaner? Uses of Bases Oven Cleaners Bases are 7.1 to 14 on the pH Scale. With bases, higher numbers are stronger. What’s wrong with letter B? Acids are 0 to 6.9 on the pH scale. Bases are the bigger numbers! (7.1 to 14)

What’s wrong with letter A? In phenolphthalein, bases turn pink. Acids form hydronium ions. Also, bases form hydroxide ions. Reminder: HydoniYUM! Base Phenolphthalein Pink Phenolphthalein Pink