Question

The molarity of a solution containing $ 5\,\,g $ of $ NaOH $ in $ 450\,\,mL $ solution will be

• A. $ 0.189\,\,mol\,\,d{{m}^{-3}} $
• B. $ 0.278\,\,mol\,\,d{{m}^{-3}} $
• C. $ 0.556\,\,mol\,\,d{{m}^{-3}} $
• D. $ 0.027\,\,mol\,\,d{{m}^{-3}} $

Answer 1

Answer: (B)

Molarity of the solution, if $ w $ gram of the solute is present in V mL of the solution $ M=\frac{w}{Molar\,\,mass\,\,of\,\,solute}\times \frac{1000}{V} $ $ =\frac{5}{40}\times \frac{1000}{450} $ $ =0.278\,\,mol\,\,{{L}^{-1}} $ $ =0.278\,\,mol\,\,d{{m}^{-3}} $