Lesson 9 Part 1
Atoms are the basic units of matter. They are made up of three particles: protons, neutrons and electrons. An atom has the same number of protons and electrons. Protons have a positive charge, and electrons have a negative charge. If an atom loses one or more electrons, it becomes a positively charged ion, which is called a cation. If an atom gains one or more electrons, it becomes a negatively charged ion, which is called an anion.
Sodium chloride (NaCl), for example, which is also known as table salt, is composed of sodium ions and chloride ions. In a solution of sodium chloride, which is commonly called salt water, sodium chloride resolves into the cation of Na+ and the anion of Cl-. This process is called ionization.
Sodium chloride (NaCl), for example, which is also known as table salt, is composed of sodium ions and chloride ions. In a solution of sodium chloride, which is commonly called salt water, sodium chloride resolves into the cation of Na+ and the anion of Cl-. This process is called ionization.
Lesson 9 Part 1-1
Atoms are the basic units of matter.
Lesson 9 Part 1-2
They are made up of three particles: protons, neutrons and electrons.
Lesson 9 Part 1-3
An atom has the same number of protons and electrons.
Lesson 9 Part 1-4
Protons have a positive charge, and electrons have a negative charge.
Lesson 9 Part 1-5
If an atom loses one or more electrons, it becomes a positively charged ion, which is called a cation.
Lesson 9 Part 1-6
If an atom gains one or more electrons, it becomes a negatively charged ion, which is called an anion.
Lesson 9 Part 1-7
Sodium chloride (NaCl), for example, which is also known as table salt, is composed of sodium ions and chloride ions.
Lesson 9 Part 1-8
In a solution of sodium chloride, which is commonly called salt water.
Lesson 9 Part 1-9
Sodium chloride resolves into the cation of Na+ and the anion of Cl-.
Lesson 9 Part 1-10
This process is called ionization.
Lesson 9 Part 2
When you place electrodes in an electrolyte solution and apply a voltage to the electrodes, electric current flows through the electrolyte. During the process, chemical changes occur on the surfaces of the electrodes. At the negative electrode, or cathode, cations move to it and receive electrons. On the other hand, anions move to the positive electrode, or anode, and lose electrons. The process that occurs when electricity passes through an ionic solution is called electrolysis.
Electrolysis is used to separate elements from a compound. For example, it is used to separate hydrogen and oxygen from water. In the experiment of water electrolysis, hydrogen gas is produced at the cathode, where hydrogen ions (H+) get electrons. At the anode, hydroxide ions (OH-) lose electrons to produce oxygen gas and water molecules.
Electrolysis is used to separate elements from a compound. For example, it is used to separate hydrogen and oxygen from water. In the experiment of water electrolysis, hydrogen gas is produced at the cathode, where hydrogen ions (H+) get electrons. At the anode, hydroxide ions (OH-) lose electrons to produce oxygen gas and water molecules.
Lesson 9 Part 2-1
When you place electrodes in an electrolyte solution and apply a voltage to the electrodes.
Lesson 9 Part 2-2
Electric current flows through the electrolyte.
Lesson 9 Part 2-3
During the process, chemical changes occur on the surfaces of the electrodes.
Lesson 9 Part 2-4
At the negative electrode, or cathode, cations move to it and receive electrons.
Lesson 9 Part 2-5
On the other hand, anions move to the positive electrode, or anode, and lose electrons.
Lesson 9 Part 2-6
The process that occurs when electricity passes through an ionic solution is called electrolysis.
Lesson 9 Part 2-7
Electrolysis is used to separate elements from a compound.
Lesson 9 Part 2-8
For example, it is used to separate hydrogen and oxygen from water.
Lesson 9 Part 2-9
In the experiment of water electrolysis.
Lesson 9 Part 2-10
Hydrogen gas is produced at the cathode, where hydrogen ions (H+) get electrons.
Lesson 9 Part 2-11
At the anode, hydroxide ions (OH-) lose electrons to produce oxygen gas and water molecules.
Lesson 9 Part 3
An acid is a substance that forms hydrogen ions when dissolved in water. An acid has some unique characteristics. As you know, aqueous solutions of acids turn blue litmus red, and they turn green BTB yellow. They have a pH of less than 7.
An alkali is a substance that dissolves in water to produce hydroxide ions. Aqueous solutions of alkali change red litmus to blue, and they have a pH of more than 7.
If you mix an acid and an alkali together, hydrogen ions (H+) and hydroxide ions (OH-) react to produce H2O. As the reaction progresses and the concentration of hydrogen ions equals that of hydroxide ions, the mixture is neither acid nor alkali. It’s neutral. We call this reaction neutralization.
An alkali is a substance that dissolves in water to produce hydroxide ions. Aqueous solutions of alkali change red litmus to blue, and they have a pH of more than 7.
If you mix an acid and an alkali together, hydrogen ions (H+) and hydroxide ions (OH-) react to produce H2O. As the reaction progresses and the concentration of hydrogen ions equals that of hydroxide ions, the mixture is neither acid nor alkali. It’s neutral. We call this reaction neutralization.
Lesson 9 Part 3-1
An acid is a substance that forms hydrogen ions when dissolved in water.
Lesson 9 Part 3-2
An acid has some unique characteristics.
Lesson 9 Part 3-3
As you know, aqueous solutions of acids turn blue litmus red.
Lesson 9 Part 3-4
And they turn green BTB yellow.
Lesson 9 Part 3-5
They have a pH of less than 7.
Lesson 9 Part 3-6
An alkali is a substance that dissolves in water to produce hydroxide ions.
Lesson 9 Part 3-7
Aqueous solutions of alkali change red litmus to blue.
Lesson 9 Part 3-8
And they have a pH of more than 7.
Lesson 9 Part 3-9
If you mix an acid and an alkali together.
Lesson 9 Part 3-10
Hydrogen ions (H+) and hydroxide ions (OH-) react to produce H2O.
Lesson 9 Part 3-11
As the reaction progresses and the concentration of hydrogen ions equals that of hydroxide ions.
Lesson 9 Part 3-12
The mixture is neither acid nor alkali. It’s neutral.
Lesson 9 Part 3-13
We call this reaction neutralization.