Solutions, Dilutions and molarity calculations

why is a conic flask, rather than a beaker, used in the investigate? To allow easy change integrity of final results by swirling. 2. Why is the funnel bear off from the burette after adding the acid solution? so that the drops from the funnel bequeath not fall into the burette. 3. In using a burette, why is it crucial to (a) rinse it with a little of the solution it is going to contain? to remove any residual peeing and so avoid dilution of the acid solution when it is poured into the burette. (b) to clamp it vertically? to enable the liquid level to be get hold of correctly. ) to have the part below the tap full? to ensure that the essential volume of liquid delivered into the flask is read correctly. 4. Give genius causa for carrying out the pastime procedures during the titration. (i) The sides of the conical flask were washed down with deionised water? To ensure that all of the acid added from the burette can react with the base. (ii) The conical flask was freq uently swirled or shaken? To ensure complete mixing of the reactants. 5. Why is a rough titration carried out? To find the approximate finish up point.This nformation enables the subsequent titrations to be carried out more quickly. 6. Why is more than one sinless titration carried out? To minimise error by getting accurate readings within 0. 1-3 cm of each other. 7. Explain why hydrochloric acid is not used as a primary banner? The exact parsimony of any hydrochloric acid solution is not known, unless it is prepared from standard ampoules. laboratory grade hydrochloric acid is not sufficiently utter(a). 8. Can any of the following be used as primary standards NaOH, H2S04, HN03? Explain your answer.A primary standard should be available in a highly pure land and stable. None of these substances are available pure because (a) NaOH readily absorbs water and carbon dioxide from the air. (b) Concentrated H2S04 readily absorbs water from the air. (c)HN03 breaks down releasing N02 gas. 9. If you used altogether 10cm3 of sodium carbonate solution in the conical flask, calculate how oft acid would be required to thieve it. x 10-3 moles Na2C03 10cm3 Na 2CO 3 solution used at concentration of 0. 1 M 1 2 x 10-3 moles HCL required Concentration of HCL is 0. M 1000 x 2 x 10-3 / 0. 23crn3 required = 10. 5crn fi13. 10. Describe briefly how a pure dry sample of sodium chloride could be obtained having carried out the titration? Using the tuition provided by the titration results, add Just enough hydrochloric acid to exactly neutralise 25cm 3 of sodium carbonate. The indicator should not be added. Gently heat up the solution until all the water has evaporated to dryness. A sample of sodium chloride will remain in the beaker. Solutions, Dilutions and molarity calculations By AbigailHerbert