Question 19 A chemist dissolves of pure hydroiodic acid in enough water to make up of solution. Calculate the pH of the solution. Round your answer to significant decimal places.

The question is incomplete , complete question is:

A chemist dissolves 640.0 mg of pure hydroiodic acid in enough water to make up 280.0 mL of solution . Calculate the pH of the solution. Round your answer to significant decimal places.

1.8 is the pH of the solution.

Explanation:

Mass of hydroiodic acid = 640.0 mg = 0.640 g

1 mg = 0.001 g

Moles of hydroiodic acid =

1 mole of hydroiodic acid gives 1 mole of hydrogen ions and 1 mole of iodide ions.

Then 0.005 moles of hydroiodic acid will give :

1 × 0.005 mol = 0.005 mol

Moles of hydrogen ions = 0.005 mol

Volume of the hydroiodic solution = 280.0 mL - 0.280 L ( 1 mL = 0.001 L)

The pH of the solution is given by :

1.8 is the pH of the solution.

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b