chemical changes

• What do acids react with to produce a salt and hydrogen?

  Some metals
• What is produced when an acid reacts with a metal?

  A salt and hydrogen gas
• What type of reactions are acid-metal reactions?

  Redox reactions
• How can you identify which substances are oxidized or reduced in a reaction?

  By looking at electrons gained and lost
• What does OIL RIG stand for?

  Oxidation Is Loss, Reduction Is Gain
• What is the ionic equation for magnesium reacting with hydrochloric acid?

  Mg -> Mg$^{2+}$ + 2e$^{-}$
• In the reaction of magnesium with hydrochloric acid, what happens to magnesium?

  It loses electrons and is oxidized
• What is the ionic equation for hydrogen in the reaction with hydrochloric acid?

  2H$^{+}$ + 2e$^{-}$ -> H$_{2}$
• What is produced when acids are neutralized by alkalis?

  Salts and water
• What is the general equation for acid and alkali reactions?

  Acid + Alkali -> Salt + Water
• What do acids produce when neutralized by metal carbonates?

  Salts, water, and carbon dioxide
• What is the general equation for acid and metal carbonate reactions?

  Acid + Metal Carbonate -> Salt + Water + Carbon Dioxide
• What does the type of salt produced in alkali and base reactions depend on?

  The acid used
• What salt does hydrochloric acid produce?

  Chlorides
• What salt does nitric acid produce?

  Nitrates
• What salt does sulfuric acid produce?

  Sulfates
• What must the charges on the positive and negative ions from the acid and base do?

  Add up to zero
• What is the resulting salt when sodium hydroxide reacts with sulfuric acid?

  Na$_{2}$SO$_{4}$
• What can soluble salts be made from?

  Acids and solid insoluble substances
• What is the first step in making soluble salts from acids?

  Add the chosen solid insoluble substance to the acid
• How do you know when the acid has been neutralized during salt production?

  Excess solid sinks to the bottom
• What is the process called after filtering out excess solid in salt production?

  Crystallisation
• What do acids produce in aqueous solutions?

  H$^{+}$ ions
• What do alkalis produce in aqueous solutions?

  OH$^{-}$ ions
• What does the pH scale measure?

  The acidity or alkalinity of a solution
• What is the pH of a neutral solution?

  7
• What does a pH less than 7 indicate?

  The solution is acidic
• What does a pH greater than 7 indicate?

  The solution is alkaline
• What is the ionic equation for any neutralization reaction?

  H$^{+}$(aq) + OH$^{-}$(aq) -> H$_{2}$O(l)
• What can be measured using titration?

  The volumes of acid and alkali solutions
• What is the first step in carrying out a titration?

  Wash burette with dilute hydrochloric acid
• How should the burette be filled for titration?

  To 100cm$^{3}$ with acid
• What is the purpose of using a pipette in titration?

  To add a specific volume of alkali
• What does phenolphthalein indicate in titration?

  It shows when the solution is neutral
• What is the titre in a titration?

  The volume of acid needed to neutralize
• Why should the titration experiment be repeated?

  To gain more precise results
• What do metals react with to form metal oxides?

  Oxygen
• What happens to ions when an ionic substance is melted or dissolved?

  The ions are free to move about
• What is the process of electrolysis?

  Breaking down substances using electric current
• Why are these reactions called oxidation reactions?

  Because metals gain oxygen