Calculate the number of millimoles contained in 500mg of FeSO4•C2H4(NH3)2SO4.4H20 Calculate the number of grams of BaCrO4 that would have to be dissolved and diluted to 100ml to prepare a 0.200M solution.

Respuesta :

Answer:

[tex]Millimoles\ of\ FeSO_4.C_2H_4(NH_3)_2SO_4.4H_2O= 1.3084\ millimoles[/tex]

The mass of [tex]BaCrO_4[/tex] required = 5.0674 g

Explanation:

The formula for the calculation of moles is shown below:

[tex]moles = \frac{Mass\ taken}{Molar\ mass}[/tex]

Given :

Mass = 500 mg

Molar mass of [tex]FeSO_4.C_2H_4(NH_3)_2SO_4.4H_2O[/tex] = 382.1455 g/mol

Thus,

[tex]Millimoles= \frac{500\ mg}{382.1455\ g/mol}[/tex]

[tex]Millimoles= 1.3084\ millimoles[/tex]

Also,

Molar mass of [tex]BaCrO_4[/tex]= 253.37 g/mol

Let the mass of the salt to prepare 100 mL 0.200 M solution = x g

The formula for the calculation of moles is shown below:

[tex]moles = \frac{Mass\ taken}{Molar\ mass}[/tex]

Thus,

[tex]Moles= \frac{x\ g}{253.37\ g/mol}[/tex]

[tex]Moles= \frac{x}{253.37}\ mol[/tex]

Given that volume = 100 mL

Also,  

[tex]1\ mL=10^{-3}\ L[/tex]

So, Volume = 100 / 1000 L = 0.1 L

Molarity = 0.200 M

Considering:

[tex]Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}[/tex]

[tex]0.200=\frac{x}{253.37\times {0.1}}[/tex]

x = 5.0674 g

The mass of [tex]BaCrO_4[/tex] required = 5.0674 g