1 / 25

Chapter 10

Chapter 10. If it is brittle, dissolves easily in water, has a high melting point and conducts electricity, it is: -an ionic compound - a covalent compound -sugar - a valence compound

ziazan
Download Presentation

Chapter 10

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 10

  2. If it is brittle, dissolves easily in water, has a high melting point and conducts electricity, it is: -an ionic compound - a covalent compound -sugar - a valence compound 2. What substances can acids react with to produce hydrogen gas? -water -sugar -metal -poison 3. When a base is added to red litmus paper, the paper turns: -red -blue -orange -green

  3. Quick Lab • Examine the 3 substances in the cups. • Answer the following questions: 1. Which two substances have similar properties? 2. What are those similar properties? • Now examine the three chemical formulas and match them to the substances Write: 3. Which two substances are made of the same elements? 4. Are properties a good way to tell which elements are in a compound? Explain

  4. Properties of Compounds • Compounds can be grouped by the kind of chemical bond they have. A chemical bond is an interaction that holds atoms or ions together. • Bonding happens between the valence electrons of different atoms.

  5. Ionic Compounds (form when atoms transfer electrons) • Properties: • brittle solids at room temperature. • Ions are arranged in a repeating three-dimensional pattern called a crystal lattice, which often breaks apart when hit. • high melting points • highly soluble in water • often conduct an electric current in solution.

  6. Covalent Compounds (form when atoms share electrons) • Properties of covalent compounds are very different from the properties of ionic compounds. • have low melting points • do not dissolve in water • do not conduct an electric current in solution. • Brittle if solid, but many are liquids or gases

  7. Acids • An acid is any compound that increases the number of hydronium ions, H3O+, when dissolved in water. • This happens when a Hydrogen ion (H+) separates from the acid and bonds with a water molecule (H2O) to form a Hydronium ion (H3O+)

  8. Properties of Acids • Acids have a sour flavor. • Many acids are corrosive, which means that they destroy body tissue, clothing, etc. • Acids react with some metals to make hydrogen gas. • Acids conduct an electric current when in solution. (Car Batteries)

  9. Acid Uses: -Sulfuric Acid used in batteries, paper making, paint -Hydrochloric Acid used in stomach to digest food -Acetic Acid is vinegar -Carbonic Acid is used in soft drinks -Citric Acid is in all citrus fruit

  10. Open book to page 287 • Read the paragraph ‘Acids React with Metals’ • On your paper answer: • How does hydrogen gas form in figure 3? • Why will this reaction take place with Zinc but not Silver? • Would the reaction take place with Sodium? Explain • How many Hydrogens are on the reactants side of the equation? How many on the products?

  11. Bases • A base is any compound that increases the number of hydroxide ions, OH-, when dissolved in water. • Hydroxide ions give bases their properties.

  12. Properties of Bases • Bases have a bitter flavor and a slippery feel. • Like acids, many bases are corrosive • Bases conduct an electric current when in solution.

  13. Bases Uses: • Baking Soda used in toothpaste and baking • Soaps – cleaning • Bleach- cleaning • Ammonia – cleaning glass • Milk – for drinking, can neutralize acids

  14. Quick Lab: Ionic or Covalent • On the back of the quick lab from yesterday: • Copy the Chart on page 284, titled ‘Melting Points of Compounds’ • Add a new column to the chart ‘Compound Type’. Then classify each compound in the chart as ionic or covalent based on the info. • Answer questions 3-5

  15. Strength of Acids and Bases • Acids and bases can be strong or weak. • The strength of an acid or a base is not the same as the concentration of an acid or base. • The concentration of an acid or a base is the amount of acid or base dissolved in water.

  16. The strength of an acid or base depends on the number of molecules that break apart when the acid or base is dissolved in water. • When all the molecules of an acid break apart in water to form ions, the acid is a strong acid.When only a few molecules of an acid break apart, the acid is a weak acid. • When all the molecules of an base break apart in water to form ions, the base is a strong base. When only a few molecules of a base break apart in water to form ions, the base is a weak base.

  17. Read the paragraph under the heading “Strong Versus Weak Acids” on page 292 Then, copy each of the following descriptions, write either strong acid or weak acid as appropriate. • Molecules do not break apart easily. • It produces many hydronium ions in solution. • Nitric acid is an example. • It produces few hydronium ions in solution. • Molecules break apart easily.

  18. If you ever had an upset stomach, you may have taken an antacid. An antacid is a weak base that neutralizes a strong acid in your stomach.

  19. Acids, Bases and Neutralization • A neutralization reaction is the reaction of an acid and a base to form a neutral solution of water and a salt. • Water (H2O) is formed when Hydrogen ions (H+) from the acid react with the Hydroxide ions (OH-) from the base • Because water is neutral, the acid and base NEUTRALIZE each other.

  20. The pH Scale • The scale goes from 1-14 • A solution that has a pH of 7 is neutral. • Basic solutions have a pH greater than 7 (up to 14) • Acidic solutions have a pH less than 7 (down to 1).

  21. Indicators • Indicators are substances that are used to identify whether something is an acid or a base. • Indicators work by changing color in the presence of an acid or a base. Examples: Phenolphthalein turns pink in the presence of a base. Bromophenol Blue turns yellow in the presence of an acid but purple in the presence of a base

  22. Salts • When an acid neutralizes a base, a salt and a water are produced. A salt is an ionic compound formed from the positive ion of a base and the negative ion of an acid. • Sodium chloride, or table salt, is only one example of a large group of compounds called salts. Salts have many uses in industry and in homes.

  23. Finish Idea Wheel On the back of the wheel answer questions on page 300 #’s 5-16. • Only letter for multiple choice • Complete sentences for the rest. • When you finish begin studying for Benchmark

More Related