Acids and Bases/The pH Scale and Indicators Flashcards
Acid Definition
A compound that produces hydrogen ions, H+ (aq), when dissolved in water.
True or False: Many acids are corrosive, and will react with metals.
True
Why do aqueous solutions of acids conduct electric current?
Because of the ions present in the solution.
What is the process called when an acid dissolves in water, and it reacts with the water to form ions?
Ionization
What is an example of ionization?
When hydrogen chloride gas is bubbled through and dissolved in water, because it reacts with water to form ions, and then the hydrogen ions and chloride ions separate in solution.
Binary Acid Definition
An acid composed of hydrogen and a non-metal/
Oxacid Definition
An acid composed of hydrogen, oxygen, and another element.
Base Definition
A compound that forms hydroxide ions, OH-(aq), when dissolved in water.
True or False: Most common acids and bases form colourless solutions.
True
What does determining the pH of a solution help you tell?
Whether an unknown solution contains an acid, a base, or neither.
What is the scale that typically ranges from 0 to 14, which is used to classify solutions as acidic, basic, or neutral?
The pH scale
pH Scale Definition
A numerical scale ranging from 0 to 14 that is used to classify aqueous solutions as acidic, basic, or neutral.
What pH values do acids have?
pH values below pH 7.
What does it mean when acids have pH values below pH 7?
There are many more hydrogen ions in the solution than hydroxide ions.
True or False: The lower the pH, the more acidic the solution is.
True
What have pH values above pH 7?
Bases
What do bases having pH values above pH 7 mean?
There are many more hydroxide ions in the solution than hydrogen ions.
True or False: The higher the pH, the more basic the solution is.
True
What type of solution neither acidic nor basic and falls in the middle of the pH scale at pH 7?
A neutral solution
What does a neutral solution having a pH of 7 mean?
There is the same number of hydrogen ions and hydroxide ions in the solution.
What are some examples of acidic solutions?
-Stomach Acid
-Lemon
-Grapes
-Tomato
-Banana
-Milk
What is an example of a neutral solution?
-Pure Water
What are some examples of basic solutions?
-Eggs
-Baking Soda
-Soap
-Ammonia
-Bleach
-Oven Cleaner
What happens when an acid and a base are mixed?
They can neutralize each other.
What is the reaction of an acid and a base to form a salt and water called?
Neutralization
Neutralization Definition
The reaction of an acid and a base to produce a salt and water.
True or False: Neutralization can be classified as a type of double displacement reaction.
True
What forms as the hydrogen ions of the acid and the hydroxide ions of the base combine?
Water
What do the other ions join to form?
A salt
True or False: Any ionic compound that is neither an acid or a base can be called a salt.
True
In most cases, the salt formed by a neutralization reaction is soluble in water and will not form a _____________.
Precipitate
Whether the _______ is added to the ________ or the _______ is added to the _______, the removal of both hydrogen ions and hydroxide ions from solution as they form molecules of water causes the pH of the mixture to approach 7.
Acid; Base; Base; Acid
What will the resulting solution be if the right amounts of acid and base react?
Neutral
Complete Practice Questions on Page 223, Page 224 (1-2) and Page 227 (1-2); Questions on Page 228, Page 231 and Page 235; Question 1 on Page 238, and Question 1 on Page 246.
Depending on Comfort Level
True or False: Acids and bases are two very important classes of chemicals that play an important role in many chemical reactions.
True
What Latin word does Acid come from, which means sour?
Acidus
What was one of the earliest uses of bases?
Making soap over 5000 years ago in Babylonia
Acids react with __________, are _____________, and __________
Metals; Corrosive; Conductive
True or False: Acids can turn blue litmus paper red and neutralize bases.
True
Why can Acids be useful in the food industry?
Because they act as disinfectants (vinegar and lemon juice) which prevent microorganisms from surviving.
True or False: Bases can turn red litmus paper blue and neutralize acids.
True
What is a Weak Acid, where are they found, and are they safe to handle? (3 points)
-Acids that are found in household items such as food, drink, and beauty/skincare products
-It is safe to handle these acids and even taste them, if they are for eating.
-They do not dissociate completely.
What is a Strong Acid? ( 2 points)
- Some acids, like those found in a laboratory or a car battery, are very dangerous (too dangerous to touch or taste).
-These acids are said to be strong as they can damage other materials by wearing them away.
True or False: Both acids and bases can cause severe chemical burns so never touch or taste any unknown chemical.
True
When a ____ dissolves in water, the ions separate from one another and hydroxide ions are released into the water in a process called ___________.
Base; Dissociation
Many metals react with acids. When this happens the metal fizzes as ________ are produced.
Bubbles
When a metal reacts with an acid, the products are a _______ and hydrogen gas.
Salt
True or False: The salt produced depends on the metal and type of acid involved in the reaction.
True
Many acids are able to conduct electricity so they are ___________.
Conductive
Since acids are covalent compounds, they have no _____ to begin with.
Ions
But, collisions with __________ ___________ break the acid molecule apart into its respective ions.
Water Molecules
Bases are substances that conduct electricity and can change the colour of ______ ________ _______
Acid-Base Indicators
What do Bases feel and taste like?
They feel slippery and taste bitter (even though most should not be tasted).
What is a Weak Base? (2 Points)
- Bases that are found in soaps and other materials used for cleaning.
-It is safe to handle these bases, which can feel soapy; these are known as weak bases.
What is a Strong Base? (2 Points)
-Some bases, like those in a laboratory or cleaning materials, are too dangerous to touch.
-These bases are said to be strong because they can burn skin and damage other materials.
What does it mean when bases are conductive?
They are good conductors of electricity.
True or False: Most bases are ionic compounds, so they are made of ions (unlike acids)
True
Several natural chemicals and many synthetic (human-made) chemicals _____ _______ when they are placed in acidic or basic solutions
Change Colour
What is a substance that changes its colour depending on the pH of the solution known as?
An acid-base indicator
True or False: Litmus is a special type of paper treated with a specific indicator that tests for acidity/basicity
True
What is an electronic pH Meter used for? (2 points)
-To determine the pH of a solution.
-These meters use the electrical properties of a solution to determine pH.
pH Indicator Definition
A substance that changes colour to show the concentration of hydrogen ions and hydroxide ions in a solution.
True or False: In a neutral solution, neither red nor blue litmus paper changes colour.
True
To more accurately determine the ____ of. a solution, several indicators that cover the pH range between pH 0 and pH 14 must be used.
pH
What is universal indicator?
A mixture of several indicators that produce a different colour at different pH values.
How is the pH paper prepared?
By soaking strips of paper in universal indicator and then allowing them to dry?
True or False: A drop of solution to be tested in placed on the pH paper. The resulting colour is compared against a colour chart to determine the pH of the solution.
True
