Partial and total concentration in solutions The total pressure of gas mixture equals the sum of partial pressures of its components.


Can this rule be true for liquid concentration?
I.e. can we say: the total concentration of mixture is equal to the sum of partial concentrations of its components?
It's true and false.

For example: 
1 Solution with 1mol/L of NaCl and 1mol/L of KBr.
The total concentration of salts is 2mol/L.

But the ions concentration are:

Na+ 1mol/L
K+ 1mol/L
Cl- 1mol/L
Br- 1mol/L

Is it clear?