Vitamin A has a molecular formula C20 H30 O. The number of vitamin A molecules in 500mg of its capsule will be:

Actually that is 500 mg so we first have to convert it into grams
And then find the molar mass of Vitamin A formula which is 286 g.

Now 286g contain 6.023*1023

So 0.5 g contain how much ?

So we simply multiply the NA with the 0.5 and divided by 286

Which gives us about 1.05*10^21

The molarity of bromide ions is 0.348 M.

Explanation:

To calculate the moles of cadmium nitrate, we use the equation:

      .....(1)

Molarity of silver nitrate = 0.7170 M

Volume of silver nitrate = 24.52 mL = 0.02452 L   (Conversion factor: 1 L = 1000 mL)

Putting values in equation 1, we get:

The chemical equation for the reaction of silver nitrate and bromide ions follows:

By Stoichiometry of the reaction:

1 mole of silver nitrate reacts with 1 mole of bromide ions.

So, 0.0174 moles of silver nitrate will react with = of bromide ions.

Now, calculating the molarity of bromide ions by using equation 1, we get:

Moles of bromide ions = 0.0174 moles

Volume of solution = 50 mL = 0.05 L

Putting values in equation 1, we get:

Hence, the molarity of bromide ions is 0.348 M.