Question

Anyone help me with this please?: Making the simplistic assumption that the dissolved NaCl(s) does not affect the volume of the solvent water, determine the constants m and b in the equation Molarity = m*density + b that relates the NaCl molarity to the NaCl(aq) density. Take the density of water to be 1.00 g/ml and the molar mass of NaCl to be 58.5 g/mol.

Answer 1

@aaronq Please can you Help here ?

Answer 2

Hm, i'm sute you have: \(M_{NaCl_(aq)}=x*\rho_{NaCl(aq)}+y\)

you can substitute: \(\dfrac{n_{solute}}{L_{solution}}=x*\dfrac{m_{solute}}{V_{solution}}+y\)

substitute further: \(\dfrac{\dfrac{m_{NaCl}}{M_{NaCl}}}{L_{solution}}=x*\dfrac{m_{NaCl}}{V_{solution}}+y\)


You could assume that \(L_{solution}=V_{solution}=1\;L\) then i would graph it

Answer 3

and so you have:***

Answer 4

or you can solve for x and y algebraically, if you notice, it's the equation of a line y=mx+b

m=\(\dfrac{y_2-y_1}{x_2-x_1} =\dfrac{\dfrac{m_2}{M_{NaCl}}-\dfrac{m_1}{M_{NaCl}}}{m_2-m_1}\)


then solve for b like you would for any old line equation

Answer 5

Sorry, was away for a bit...Thank you goformit100 and thank you aaronq!

Answer 6

no problem dude!