Question

an aqueous BeCl2 solution has a mass percentage of 8% and a density of 1.10g/mL. A person takes 10mL of the solution and adds water till the total volume is 500mL, what is the molarity of BeCl2?

Answer 1

@maheshmeghwal9 something we can work on together? :)

Answer 2

Wt did u do upto this?

Answer 3

An aqueous solution of BeCL2 = water + BeCL2.

Answer 4

so now the question is more easy to think upon:)

Answer 5

yes, so i know that:
\[\rho=1.10g/mL and that \rho=m/v\]
\[molarity= mass solute/L solution (M)\]
mass % = 8% =(mass solute/mass solution) x100
V1=10mL and V2=500mL

Answer 6

I think u should let BeCl2's mass be 'x'.
do u agree?

Answer 7

so i got the mass of BeCl2 by solving the density equation for mass: m=vp = 1.10 x 500?

Answer 8

You can solve the problem in that way:
Each value you obtain goes in the next line.

- 10 mL of solution have a mass of.........................................g
- ....... g of solution have a mass of BeCl2 of............................g
- ........g of BeCl2 represent an amount of BeCl2 of...................mol.
- ....... mol of BeCl2 in 500mL make a concentration of.............mol/L

Answer 9

@Vincent-Lyon.Fr , this is how far I got with the explanation:
10mL of BeCl2 solution has a mass of 11g.
I don't understand what you mean by the 2nd part.

Answer 10

Next step is :

11 g of solution contain how many g of BeCl2 ?
Remember mass percentage is 8%

Answer 11

oo okay, then it contains 0.88gBeCl2!
thank you!!^^