Question

1. test: before you begin testing with the 4.5 - 7.5 paper, list the ph values of the substances below that you found using the 0 - 14 ph indicator paper. then find the ph of each substance with the 4.5 - 7.5 paper.

material in the tube	ph value (0 to 14 paper)	ph value (4.5 to 7.5 paper)
milk	7	6.5
oven cleaner	13	7.5
saliva (human)	7	6.5
shampoo	7	7
stomach acid	1	4.5
water (distilled)	7	7

1. analyze: compare the ph values in each column.

a. how do these values compare?

Explanation:

Step1: Observe the pH values

For substances with pH values outside 4.5 - 7.5 range using 0 - 14 paper, the 4.5 - 7.5 paper gives either 4.5 or 7.5. For substances within the 4.5 - 7.5 range using 0 - 14 paper, the 4.5 - 7.5 paper gives a more precise value within that narrower range.

Step2: Compare columns

Substances like coffee with pH 5 on 0 - 14 paper has the same value on 4.5 - 7.5 paper as it is within the 4.5 - 7.5 range. Milk has a more precise value (6.5) on 4.5 - 7.5 paper compared to 7 on 0 - 14 paper. Oven cleaner with pH 13 on 0 - 14 paper has a value of 7.5 on 4.5 - 7.5 paper as it is above the 4.5 - 7.5 range.

Answer:

The pH values from the 4.5 - 7.5 paper are more precise for substances with pH values originally within the 4.5 - 7.5 range when measured with the 0 - 14 paper. For substances with pH values outside the 4.5 - 7.5 range when measured with the 0 - 14 paper, the 4.5 - 7.5 paper gives the boundary value (4.5 or 7.5) of its range.