Question

How to calculate the error propagation for the molarity of a NaCl solution

Answer 1

The general method to calculate error propagation for any solution is attached in the below image

here m = mass (grams)

M = molar mass (gm/mol)

V = volume ( litre)

u(m) is uncertainity or relative error of mass

u(M) is uncertainity in molar mass

u(V) is uncertainity in volume

concentration = c = n/V mol/litre

here n- number of moles

molar mass = m/n

c =m/MV

then let u(c) be the uncertainity or relative error of concentration

then we have a relation

u(c)/c = ((u(m)/m) + (u(M)/M) + (u(V)/V))^0.5

then we get absolute error of concentration

u(c) =  ((u(m)/m) + (u(M)/M) + (u(V)/V))^0.5 * c

we get u(c) that is relative error of concentration

then concentration c = ( c + or - u(c)) mol/litre

this is the final concentration and used to calculate molarity

This is how we calculate error propagation for molarity.