Year 10 Chemistry

• Strong acids are said to be corrosive as they can damage other materials by wearing them away. These are found in the lab or a car battery, are too dangerous to taste or touch.
• Alkalis are substances that are chemically opposite of acids. Weak alkalis are found in soap and other cleaning materials. They are also used in antacids to treat indigestion.

  Some alkalis used in labs or in cleaning materials are too dangerous to touch.These alkalis are said to be caustic because they can burn skin, and damage other materials.
• The pH scale measures how acidic or alkaline something is. It ranges from 0-14. The lower the number on the scale, the more acidic it is. The higher the number, the more alkaline it is. A pH of 7 means it's neither acidic nor alkaline - this is called neutral.
• A neutralisation reaction is when an acid reacts with an alkali to form salt and water
• A solution with a pH less than 7 is an acid. Solutions with a pH greater than 7 are bases (alkali).
• Acid + Alkali → Salt + Water
• Salt + Acid → Salt + Water
• Salt + Alkali → Salt + Water
• Water + Acid → Water + Hydrogen gas
• Salt + Alkali → Salt + Alkali
• Salt + Acid → Acid + Salt
• An ion is an atom or molecule that has gained or lostelectrons, giving it an overall electricalcharge.

  Whether a substance is an acid or a base depends on the type of ions it releases when it dissolves in a solution.

  • Acids release hydrogen ions (H+) in solution.
  • Bases release hydroxide ions (OH–).

  As shown in the diagram, a hydrogen ion is simply a hydrogen atom that has lost an electron, giving it a positive charge. A hydroxide ion is made up of an oxygen atom bonded to a hydrogen atom. It has an overall negative charge.
• the higher the concentration of H+, the more acidic it is, and the lower the concentration of H+ ions, the more basic it is.
• A colloid is a mixture in which very small particles of one substance are distributed evenly throughout another substance. The particles are generally larger than those in a solution, and smaller than those in a suspension. Paints, milk, and fog are colloids.
• a mixture is a substance made by mixing other substances together.
• a solution is a special type of homogeneous mixture composed of two or more substances. 
• Acid


  A substance with a pH less than 7
• Acids


  • Tasting sour
  • Dissolving some metals
• Acid–carbonate reaction


  1. Neutralization reaction

  2. Produces a salt

  3. Produces water

  4. Produces carbon dioxide gas
• Acidification


  A decrease in a substance's pH
• Acidification


  • Ocean acidification is the decrease in the pH of sea water due to carbon dioxide absorbed from the air
• Alkali


  A base that dissolves in water
• Base


  A substance with a pH greater than 7
• Bases


  • Tasting bitter
  • Having a soapy, slippery feel
• Caustic


  Able to burn or corrode, especially living materials such as skin
• Corrosive


  Able to damage or destroy another substance by a chemical reaction
• Hydrogen ion


  An ion that is released by acids in solution
• Hydroxide ion


  An ion that is released by bases in solution
• Indicator


  Any substance that changes colour when mixed with an acid or base
• Indicators


  • Litmus paper
  • Universal indicator
• Ion


  An atom or molecule with a net charge
• Litmus


  A dye that turns red in acidic solutions and blue in basic solutions
• Litmus does not indicate the strength of the acid or base
• Neutral substance


  A substance with a pH of 7
• Neutralization


  A reaction between an acid and a base to produce a salt and water
• pH scale


  The standard way of measuring the strengths of acids and bases
• pH is a number from 0 to 14 that relates to the concentration of hydrogen ions in a solution
• Reactive


  Tending to chemically interact with other substances
• Reactive


  • Acids are highly reactive with some metals
  • Hydrochloric acid reacts with magnesium
• Solution


  A type of mixture formed when one substance dissolves in another