Acids

• 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
• What type of reactions occur when acids react with metals?


  Redox reactions
• How can you identify which substances are oxidised and reduced in a redox reaction?


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


  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 oxidised
• What is the ionic equation for hydrogen in the reaction with hydrochloric acid?


  2H$^{+}$ + 2e$^{-}$ -> H$_{2}$
• What is the significance of magnesium being oxidised and hydrogen being reduced in the same reaction?


  It indicates that the reaction is a redox reaction
• What do acids neutralise with to produce salts and water?


  Alkalis and bases
• What is the general equation for the neutralisation of an acid by an alkali?


  Acid + Alkali -> Salt + Water
• What do acids produce when they react with metal carbonates?


  Salts, water, and carbon dioxide
• What is the equation for the reaction of an acid with a metal carbonate?


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


  The acid used
• What type of salt does hydrochloric acid produce?


  Chlorides
• What type of salt does nitric acid produce?


  Nitrates
• What type of salt does sulfuric acid produce?


  Sulfates
• What does the salt produced in acid-base reactions depend on besides the acid used?


  The positive ions in the base, alkali, or carbonate
• What must the charges on the positive and negative ions from the acid and base add up to?


  Zero
• If sodium hydroxide reacts with sulfuric acid, what is the resulting salt?


  Na$_{2}$SO$_{4}$
• What ions do acids produce in aqueous solutions?


  H$^{+}$ ions
• What ions 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 purpose of titration in chemistry?


  To measure the volumes of acid and alkali solutions that react with each other
• What is the first step in carrying out a titration?


  Wash the burette using dilute hydrochloric acid and then water
• How should the burette be filled for a titration?


  To 100cm$^{3}$ with the meniscus’ base on the 100cm$^{3}$ line
• What volume of alkali should be added to the conical flask during a titration?


  25cm$^{3}$
• What should be added to the conical flask after the alkali?


  A few drops of a suitable indicator
• What color does phenolphthalein turn when alkaline?


  Pink
• What does the end-point of a titration indicate?


  That the acid has been neutralised
• How is the titre calculated in a titration?


  By finding the difference between the first and second readings on the burette
• Why should the titration experiment be repeated?


  To gain more precise results
• How many cm$^{3}$ are in 1 dm$^{3}$?


  1000 cm$^{3}$
• What is the relationship between moles and relative atomic mass?


  One mole of a substance in grams is the same as its relative atomic mass in grams
• How do you calculate the moles of NaOH in a titration?


  By using the formula moles = volume x concentration
• What defines a strong acid in aqueous solution?


  It is completely ionised
• Which acids are considered strong acids?


  Hydrochloric, nitric, and sulfuric acids