Calculate the number of molecules in a sample of carbon dioxide with a mass of 168.2 grams

2.30x10²⁴ molecules CO2

Explanation: Solution:

Convert mass of CO2 to moles

Convert moles of CO2 to molecules using Avogadro's number.

168.2 g CO2 x 1 mole CO2 / 44 g CO2 x 6.022 x10²³ molecules CO2 / 1 mole CO2

= 2.30 x10²⁴ molecules CO2

answer: option (a) is the correct answer.

explanation:

the measurement of hydrogen ions in a solution is known as ph.

if ph of a solution is less than 7 then the solution is acidic. if ph of a solution is greater than 7 then the solution is basic.

when the ph of a solution equals 7, then the solution is considered as neutral.

the ph of pure water is 7, therefore, it means that concentration of hydronium ions equals that of hydroxide ions.