The flask with phenolphthalein and NaOH changes color when the ___ gas formed during respiration was passed through the solution. The gas dissolves in the solution and forms. Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a) oxygenwater b) carbon dioxidewater c) carbon dioxidecarbonic acid d) nitrogenammonia

c

Explanation:

The flask with phenolphthalein and NaOH changes color when the carbon dioxide gas formed during respiration was passed through the solution. The gas dissolves in the solution and forms carbonic.

The dissolution of CO2 into an aqueous solution of NaOH is a two steps reaction.

1. CO2 first reacts with water to form carbonic acid

This makes the phenolphthalein to change color.

2. The product in step 1 reacts with NaOH to form NaHCO3 and water

Hence, the correct option is c.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

your answer is "the 1950's"