1 / 17

Acids and Alkalis

Acids and Alkalis. What are acids and alkalis?. What are bases?. All alkalis are bases . Bases are substances that react with acids by absorbing hydrogen ions ( H + ). The oxides, hydroxides and carbonates of metals, such as sodium hydroxide, are bases.

selene
Download Presentation

Acids and Alkalis

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. Acids and Alkalis

  2. What are acids and alkalis?

  3. What are bases? All alkalis are bases. Bases are substances that react with acids by absorbing hydrogen ions (H+). The oxides, hydroxides and carbonates of metals, such as sodium hydroxide, are bases. Some bases are soluble in water. These are called alkalis. All alkalis contain hydroxide ions (OH–). The more OH– ions in the solution, the stronger the alkali.

  4. What are indicators? Indicators are chemicals that change colour in the presence of an acid or an alkali. There are many different indicators. Lots of them come from plants, like red cabbage. Different indicators turn different colours. Geranium plants grown in acidic soil have red flowers, while geraniums grown in alkali soil have blue flowers. Universal indicator is a mixture of indicators. It is useful because it shows a range of colours from pH 1–14.

  5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 What does the pH scale show? The pH scale runs from 1 to 14. The numbers 1 to 6 represent acidic conditions and 8 to 14 represent alkali conditions. A pH value 7 is neutral. What are the pH values of some everyday items?

  6. What does the pH scale show?

  7. What is the order of pH?

  8. Acids and bases – true or false?

  9. Making salts

  10. pH change during neutralization

  11. + + acid base  salt water How are salts made and named? When an acid reacts with a base, a neutralization reaction occurs and produces a chemical called a salt. The name of the salt depends on the names of the reactants. • The first part of the salt’s name comes from the metal in the base: e.g. sodium hydroxide sodium…  • The second part of the salt’s name comes from the acid: e.g. sulfuric acid …sulfate  For example, if sodium hydroxide neutralizes sulfuric acid, the product is a salt called sodium sulfate.

  12. Naming salts

  13. Making salts with an acid and an alkali When an acid reacts with an alkali, H+ ions from the acid and OH- ions from the alkali combine to produce a salt and water. Water is formed because the oxygen and hydrogen from the alkali react with the hydrogen from the acid to produce molecules of water (H2O). For example: hydrochloricacid sodiumhydroxide sodiumchloride + +  water + +  HCl (aq) NaOH(aq) NaCl (aq) H2O (l)

  14. Glossary

  15. Multiple-choice quiz

More Related