Question

A solution was made by combining 145 (±1) mL of 0.250 (±0.003) M NaCl with 275.0 (±0.5) mL of 6.00 (±0.01) wt% NaCl (assume this solution’s density is 1.0413 g/mL and the molar mass of NaCl is 58.443 g/mol, both with negligible error) in a 500.00 mL volumetric flask, and filling with water up to the line.

How many mmol of NaCl are in the final solution? Include absolute error in your number of millimoles and round your answer to an appropriate number of sig figs.

(HINT: First find the number of millimoles of NaCl, ignoring the error. Then go back and propagate error properly through each calculation step. )