An isopropyl solution contains 70 ml of isopropyl alcohol in 1.8 L of water. What is the percent by volume of the alcohol

3.74%

Explanation:

We express a solution's volume by volume percent concentration, % v/v,

Take the ratio of the isopropyl alcohol (IPA) volume to the total volume of the solution, which is 1800 mL of water + 70 mL of IPA,

and multiply by 100 to get the percentage: 70 / (1800+70) * 100 = 0.0374*100 = 3.74%