Acids and Bases

pH- power of the hydrogen ion

Difference between them…

• Basically, acids are defined as compounds which give off H+ ions when you put them in water

• Bases are compounds that give off OH- ions in water

Properties of acids

• React with most metals for form hydrogen gas• Taste sour• Frequently feels sticky• Usually in the form of gases or liquids

Properties of bases

• Feels slippery• Taste bitter• Reacts with oil and greases• Frequently solids

The pH scale

• Measurement of H+ concentration in a liquid• High concentration= acid• 0-6 acid• 0= strongly acidic• 7 neutral. 6.99 is still “acidic” and 7.01 is

“basic”• 8-14 base• 14= strong base

Our Mini Lab on Acids and Bases

• In this lab, you will predict and discover the relative pH of items easily found around the house

• Materials: tums, soap, washing detergent, coke, vinegar, baking soda, windex, lemonade, apple juice, milk, milk of magnesia, shampoo, distilled water

Your lab report

• You will turn in a chart YOU CREATE. ONLY turn in the chart

• Chart the following items:– Material name– Predicted pH– Color of red litmus paper– Color of blue litmus paper– Numeric result of pHydrion paper– Acid or base

Chart should look something like this

procedure

• Create chart. Make sure your name is on it• Predict “acid or base” for each item• Test each compound with red AND blue litmus paper• Wait on everyone to finish• Teacher will test each compound with pHydrion

paper. Record numeric result• Fill in “acid or base” column• Discard litmus papers• Turn in your chart

Indicator reference Chart

• Blue litmus will turn RED in the presence of an acid

• Blue litmus will remain BLUE in the presence of a base

• Red litmus will turn BLUE in the presence of a base

• Red litmus will remain RED in the presence of an acid