1.2 Acids & Bases

A. pH Scale pH is a measurement of how many hydrogen ions (H+(aq)) are in a solution most solutions have a pH ranging from 0 to 14 acids form solutions with a pH below 7 and turn litmus red bases form solutions with a pH above 7 and turn litmus blue slide 1 of 9

a pH of 0 to 0.5 is a strong acid neutral solutions have a pH of exactly 7 and do nothing to litmus paper a pH of 0 to 0.5 is a strong acid eg) battery acid (H2SO4(aq)) a pH of 14 is a strong base eg) drain cleaner (KOH(aq)) a pH of 7 is neutral eg) distilled (pure) water slide 2 of 9

Acids Bases Neutral pH Scale lemon juice drain cleaner stomach acid milk distilled water toothpaste 1 2 6 7 10 14 strong acid strong base slide 3 of 9

B. Measuring pH exact pH can be measured with a pH meter can also use acid-base indicators which are substances that change colour when they are placed in solutions slide 4 of 9

C. Neutralization when an acid neutralizes a base (or vice versa) this is called an acid-base neutralization reaction  Acid + Base Salt (ionic compound) + Water eg)  HCl(aq) + Mg(OH)2(aq) MgCl2(aq) + H2O(l) slide 5 of 9

the products of a neutralization reaction have a pH of 7 antacids like Tums or Rolaids can be used to neutralize excess stomach acid bases can be used to neutralize acid spills and vice versa slide 6 of 9

D. Acid Rain rain water is naturally acidic (pH of about 5.6) because of CO2 dissolving in it to produce carbonic acid industries release chemicals into the atmosphere which add to the acidity of our precipitation eg) CO2(g), NOx(g) and SOx(g) slide 7 of 9

this can cause the pH of precipitation to drop to as low as 3.0!!! acid rain (precipitation) can kill aquatic and terrestrial organisms and ruin manmade structures slide 8 of 9

acid lakes can be treated with calcium hydroxide (a base)… acid-base neutralization slide 9 of 9