Apotassium bromide solution is 7.55% potassium bromide by mass and its density is 1.03 g/ml. part a what mass of potassium bromide is contained in 35.8 ml of the solution?

Answer : The mass of potassium bromide contained in 35.8 ml of solution is, 2.784 grams.

Explanation : Given,

Density of solution = 1.03 g/mole

7.55 % potassium bromide by mass means that 7.55 gram of potassium bromide present in 100 grams of solution. So,

Mass of potassium bromide = 7.55 g

Mass of solution = 100 g

First we  have to calculate the volume of solution.

Now we have to calculate the mass of potassium bromide in 35.8 ml of the solution.

As, 97.08 ml of solution present in 7.55 gram of potassium bromide

So, 35.8 ml of solution present in gram of potassium bromide

Therefore, the mass of potassium bromide contained in 35.8 ml of solution is, 2.784 grams.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.