Question

A chemist adds 30.0 ml. of a 1.10 mol/L sodium nitrate (NaNO) solution to a reaction flask. Calculate the millimoles of sodium nitrate the chemist has added to the flask. Round your answer to 3 significant digits. 00 X 5 ?

Answer 1

Given:-

Volume of sodium nitrate = 30.0 mL

= (30.0/1000) L -----(1 mL = (1/1000) L)

= 0.03 L

Concentration of sodium nitrate = 1.10 mol/L

No. of moles can be found using the formula-

Concentration(mol/L) = No.of moles Volumeinlitre

i.e., No. of moles = (Concentration).(Volume in litre) -----(a)

putting the given values in equation(a), we get,

No. of moles of sodium nitrate = (1.10).(0.03)

= 0.033 moles

= (0.033).(1000) millimoles -----(1 mole = 1000 millimoles)

= 33 millimoles

Rounding off my answer to 3 significant digits:-

No. of moles of sodium nitrate = 33.0 millimoles

The millimoles of sodium nitrate that the chemist has added to the flask is 33.0 millimoles.