We have to grade the following text and answer the questions below with a yes or

Question

We have to grade the following text and answer the questions below with a yes or no.

Here are the questions and below the questions will be the text that you have to read.

1. Does the essay contain a topic sentence that introduces the concept of titration?

2. Is the concept of titration described to be a technique where a solution of a known concentration is used to determine the concentration of another solution?

3. Does the essay indicate that the equivalence point is reached when the reaction is complete? (i.e. when the amount of the added titrant is stoichiometrically equal to the analyte?)

4. Does the essay indicate that in a titration the titrant must be a standard solution with an accurately known concentration?

5. Does the essay describe that the equivalence point is determined by recording the volume of titrant added when color change of the indicator persists (or by a rapid change in pH according to a pH meter)?

6. Is the indicator described as a substance able to change color depending on the pH of the solution?

7. Does the essay indicate that the NaOH solution should be standardized before being used as a titrant for HCL?

8. Do the instructions clearly state that an indicator is added to the HCl solution before the titration begins?

9. Does the essay provide a reason, such as a change in concentration over time, that would necessitate a standardization of the titrant solution?

10. Is the standardization of the NaOH solution described as a titration of an approximate concentration of NaOH solution with an accurately known concentration of KHP solution as the titrant?

11. Does the essay describe the method used to prepare a solution from a pure solid as first weighing the solid, dissolving the solid in an appropriate solvent (such as water), and then diluting the solution in a final volume using a volumetric flask?

12. Are all the necessary data (exact concentration/molarity of NaOH; molar ratio HCl/NaOH of 1:1; exact volume of NaOH/titrant added; and volume of analyte used) required to calculate the concentration of HCl clearly listed?

13. Does the essay describe that the concentration of HCl solution is calculated by: 1. determining the number of moles of NaOH added (concentration of NaOH multiplied by volume of NaOH); 2. then multiplying the moles of NaOH added by the stoichiometric ratio of HCl and NaOH (1:1) to determine number of moles of HCl present; 3. dividing the number of moles of HCl by the final total volume of the HCl solution?

14. Are there any spelling or grammatical errors in the essay? (none, some, many)

16. How would you rate this text? (1-10)

Titration is a method used in chemistry to find an unknown concentration, an analyte, using a known solution, a titrant. The HCl will be used as an analyte and NaOH as the titrant to perform the titration. For the titration prepare NaOH solution first, weigh the mass of NaOH used with an analytical balance and add distilled water to get the correct solution. Transfer the titrant solution to a buret and cover with an inverted test tube, place the buret standing over a beaker that contains small amounts of HCl. Preparation of a standardized solution is needed in order be able to know the exact concentration of NaOH, since NaOH reacts with the CO2 in the air it cannot give an exact concentration. To prepare the standardized solution KHP will be added to the NaOH because KHP can be used as a primary standard to calculate NaOH concentration; the moles of KHP equals its mass. This concentration will later be used to calculate the the concentration of HCl. Phenolphthalein will be placed before beginning to titrate, it will be used as indicator. If the pH is about 9 it will cause a color change in the solution, indicating an end point for the titration. The endpoint of the titration indicates the equivalence point, when moles of the titrant NaOH is equal to the moles of the analyte HCl. A method that can be use to solve the equivalence point is by using the formula Kw=KaKb, this formula can be rearranged to find the concentration needed of titrant to reach equilibrium. To calculate the concentration of HCl the overall volume of NaOH needed to activate KHP in the HCl solution is needed, the volume of HCl that was initially in the beaker, and the concentration of NaOH used. The molarity/concentration can be calculated by using the formula MNaOH VNaOH=MHClVHCl.

Titration is a method used in chemistry to find an unknown concentration, an analyte, using a known solution, a titrant. The HCl will be used as an analyte and NaOH as the titrant to perform the titration. For the titration prepare NaOH solution first, weigh the mass of NaOH used with an analytical balance and add distilled water to get the correct solution. Transfer the titrant solution to a buret and cover with an inverted test tube, place the buret standing over a beaker that contains small amounts of HCl. Preparation of a standardized solution is needed in order be able to know the exact concentration of NaOH, since NaOH reacts with the CO2 in the air it cannot give an exact concentration. To prepare the standardized solution KHP will be added to the NaOH because KHP can be used as a primary standard to calculate NaOH concentration; the moles of KHP equals its mass. This concentration will later be used to calculate the the concentration of HCl. Phenolphthalein will be placed before beginning to titrate, it will be used as indicator. If the pH is about 9 it will cause a color change in the solution, indicating an end point for the titration. The endpoint of the titration indicates the equivalence point, when moles of the titrant NaOH is equal to the moles of the analyte HCl. A method that can be use to solve the equivalence point is by using the formula Kw=KaKb, this formula can be rearranged to find the concentration needed of titrant to reach equilibrium. To calculate the concentration of HCl the overall volume of NaOH needed to activate KHP in the HCl solution is needed, the volume of HCl that was initially in the beaker, and the concentration of NaOH used. The molarity/concentration can be calculated by using the formula MNaOH VNaOH=MHClVHCl.

Explanation / Answer

ANSWER:

(1) Yes, the topic deals with the concept of titration. (2) Yes, unkown concentraion is called analyte and known concentration as titrant.(3) Yes (4) Yes, titrant must be sdandardised solution otherwise calculations will be incorrect. (5) Yes. (6) Yes. (7) Yes, because it reacts with atmospheric CO2. (8) No, It is not clearly mentioned to which solution (NaOH or HCl) indicator is to be added. (9) Yes, it mentions that titrant (NaOH) reacts with atmospheric CO2 hence its concentration will decrease. (10) No, standardization of naOH is not describd as titration. (11) No. (12) Yes. (13) Yes. (14) Some e.g. burette is written as buret. (15) 7/10.

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