A student prepared a stock solution by dissolving 10.0 g of NaOH in enough water to make 150.0 mL of solution. She then took 15.0 mL of the stock solution and
diluted it with enough water to make 65.0 mL of a final solution. What is the
concentration of the final NaOH solution?

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According to arrhenius theory of acid and bases, an acid is a proton donor, while base donates hydroxyl ions. further, acid and base reacts to form salt and water.consider following example.hcl    +      h2o          →      cl-          +      h3o+here, hcl has donated a proton, hence it is an acid.now consider following reactionhcl      +      naoh            ↔      nacl      +        h2oin this reaction, hcl donates proton, hence it is acid. on other hand, naoh donates hydroxyl ion (i.e. hence it is a base.