You want to make a 2.5% by mass NaOH, solution, how many grams of NaOH are needed if you only have 2.00 *10^3 mL of water as a solution?

1 Answer
Apr 13, 2018

#"51.0 g"#

Explanation:

Volume of water #= 2.00 × 10^3\ "mL"#

Mass of water #"= Volume × Density" = "1 g"/cancel"mL" × 2.00 × 10^3 cancel"mL" = "2.00 kg"#

#%("m/m") = "Mass of solute"/"Mass of solution" × 100#

#2.5 = "m"/"2.00 kg + m" × 100#

#"2m + 5.00 kg = 100m"#

#"m" = "5.00 kg"/98 = "0.0510 kg = 51.0 g"#