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A 250 mL sample of a 0,125 M solution of NaOH contains 1,25 g of NaOH
To calculate that, we use the definition of molar concentration (M=moles/L) and the solution volume in L to get the moles of NaOH in the solution. After that, we get the mass of NaOH from the molar mass. All these calculations are shown in the following conversion factor:
[tex]MassNaOH=250mLsol* \frac{1L}{1000mL}* \frac{0,125 mol NaOH}{1 Lsol}* \frac{39,997 g NaOH}{1 mol NaOH} \\ =1,25gNaOH [/tex]