Safety Contractbefekjb;kj;jbkvb PDF

Preview

Summary

mn vrkjbfavkjbvskjkdcb kjceb;kjekqj kjk;3jvb;jwev;kj...

Description

0Lab 02 Acids Bases and pH Buffers – Short Answer Questions EXPERIMENT 1: Fill in the table with the results found in your records. Solution

Color before addition of bromothymol blue

Color after addition pH before addition of bromothymol of bromothymol blue blue

water

clear

Green

7

acetone

Clear

Green

7

5 M citric acid

Clear

Yellow

1.22

1.22

5% vinegar

Clear

Yellow

2.41

2.41

4M Clear ammonia

Blue

11.93

11.93

diluted bleach

Blue

10.61

10.61

Clear

pH after addition of bromothymol blue

EXPERIMENT 1: Based on your results with bromothymol blue, what color would a solution that was pH 13.5 be? Blue

EXPERIMENT 2: Fill in the following table with results found in your records. Please indicate whether the change was positive (+) or negative (-). Results HCl

Test Tube Contents

Change in pH pH after HCl pH

water

7

2.01

4.99

NaH2PO4

4. 7 3.15

4.55

Na2HPO4

9. 8.16

1.56

NaOH

pH pH after NaOH Change in pH

72 7. NaH2PO4 and Na2HPO4 21 7.03

.18

EXPERIMENT 2: Which solution was the most sensitive to the addition of acid or base? Water EXPERIMENT 2: Which solution was the least sensitive to the addition of acid or base? NaH2PO4 and Na2HPO4

EXPERIMENT 2: Which of the four solutions tested is the best buffer against changes in pH caused by the addition of acid or base? NaH2PO4 and Na2HPO4...