Question

1. describe btb.
2. name three conditions where changes in proton concentration, and changes in carbon dioxide levels, cause btb to appear a different color.
3. fill in the table below with the following: green, yellow, blue, ph 0, ph 7, ph 14, and intermediate absorbance.

color	ph	absorbance
		high absorbance

Explanation:

Step1: Describe BTB

BTB (Bromothymol Blue) is a pH - indicator. It is yellow in acidic solutions (low pH, high proton concentration), blue in basic solutions (high pH, low proton concentration), and green in neutral solutions.

Step2: Name three conditions for color - change

1. Acidic condition (low pH, high proton concentration, high carbon dioxide levels as $CO_2$ dissolves in water to form carbonic acid, increasing proton concentration).
2. Neutral condition (pH = 7, moderate proton concentration, moderate carbon dioxide levels).
3. Basic condition (high pH, low proton concentration, low carbon dioxide levels).

Step3: Fill in the table

Color	pH	Absorbance
Green	pH 7	intermediate absorbance
Blue	pH 14	high absorbance

Answer:

BTB is a pH - indicator. Three conditions are acidic, neutral, and basic. Table filled as above.