The answer is: [D]: a reactant.
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The building block that makes up all matter in the universe is atoms.
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<u>Answer:</u> The solubility of carbon dioxide at 5.50 atm is 
<u>Explanation:</u>
To calculate the molar solubility, we use the equation given by Henry's law, which is:

Or,

where,
are the initial concentration and partial pressure of carbon dioxide
are the final concentration and partial pressure of carbon dioxide
We are given:

Putting values in above equation, we get:

Hence, the solubility of carbon dioxide at 5.50 atm is 