As a "rule of thumb" there are 20 drops of a liquid in a mL. Using this estimate and a density of 1.685, how many moles are in 27 drops of 85 % by weight phosphoric acid? Use the molecular weights that you already calculated. Give two significant digits and no extraneous marks.

0.020 mol

Explanation:

Let's consider the following relations:

20 drops of a liquid have a volume of 1 mL.The density of the solution is 1.685 g/mL, that is, each milliliter of solution has a mass of 1.685 g of solution.There are 85 g of phosphoric acid per 100 grams of solution (85 % by weight).The molar mass of phosphoric acid is 97.99 g/mol

With these relations, we can calculate the moles of phosphoric acid in 27 drops of solution.

Option A kinetic energy

As the bow initially was at rest it had potential energy (an object at rest potential energy) and when it was at motion it will kinetic energy (object at rest will have kinetic energy)