Materials:
goggles aprons paper for data table graduated cylinder unknown I substance beakers/test tubes stirring rod litmus paper pH indicator paper pH color chart phenolphthalein scoopula eye-dropper digital pH meter magnesium ribbon calculator unknown II substance forceps sodium bicarbonate
Procedures:
Test the pH of the Unknown substances with litmus paper and pH indicator paper and match to color chart
Test the Unknowns with phenolphthalein solution
Add magnesium ribbon to Unknowns to see if any reactions occur
Data: (See Other Pages)
Conclusion:
In the Acid and Base Lab, we had to test the pH value of two unknown substances to determine if they were acids or bases. First, we had to test the Unknowns with litmus paper. Litmus is a dye made from a lichen-algae/fungus mixture. For the Unknown I, the litmus paper turned red which meant that it was an acid. For the Unknown II, the litmus paper turned blue which meant that it was a base. Next, we had to test the Unknowns with pH indicator paper. We then had to match the pH paper to the pH color chart. The pH value was 1 for the Unknown I. The pH value was 11 for the Unknown II. Then, we had to add phenolphthalein solution to the Unknowns. When we added it to the Unknown I, it turned cloudy and looked kind of milky. It didn't turn pink because it was an acid. When we added it to the Unknown II, it turned bright pink. This indicated that it was a base. Next, we had to add a piece of magnesium ribbon to the Unknowns. When we added it to the Unknown I, a hydrogen gas and salt was produced. It was an exothermic reaction because heat was given off. When we added it to the Unknown II, nothing happened. Then, we had to add baking soda to the Unknowns. Unknown I fizzed up to the top of the test tube and then went back down. Salt and water were produced. Unknown II turned light pink. There was no reaction because it was a base.