Science question

Sodium Hydrogencarbonate Idicator
(碳酸氫鹽指示劑)

It is a solution which used to test for the Carbon dioxide (CO2). The amount of Carbon dioxide will change the colour of the solution.
這是一種測試二氧化碳的溶液, 二氧化碳的數量將改變溶液的色。

0.03% Carbon dioxide: red in colour.
剛好0.03% 的二氧化碳: 紅色。
More than 0.03% Carbon dioxide: yellow in colour.
超過0.03% 的二氧化碳: 黃色。
Less than 0.03% Carbon dioxide: purple in colour.
少於0.03% 的二氧化碳: 紫色。

Usually for the breathed air it has more than 0.03% of Carbon dioxide.
通常人體呼出的空氣有超過0.03% 的二氧化碳。

Normal air has exactly 0.03% of Carbon dioxide
正常的空氣則剛剛好有0.03% 的二氧化碳

Hydrogen carbonate indicator = 碳酸氫鹽指示劑,

It's used for testing the carbon dioxide (CO2),
If the content of the test solution contains less than 0.03% of Carbon dioxide, the colour of the Hydrogen carbonate indicator will change into purple in color. If it contains more than 0.03% CO2, the color will change to yellow. If it contains exactly 0.03% of CO2, the color will change to red.

hydrogen carbonate indicator is a indicator...
it's use to test the CO2.
it gives birth to a reaction with CO2.
if there is less than 0.03% Carbon dioxide,
the hydrogen carbonate indicator will change into purple.
if there is 0.03% Carbon dioxide,
the hydrogen carbonate indicator will change into red.
if there is more than 0.03% Carbon dioxide,
the hydrogen carbonate indicator will change into yellow.