A compound is known to be Na2CO3, Na2SO4, NaOH, NaCL, NaC2H3O2 or NaNO3-. When barium nitrate solution is added to a solution containing the unknown a white precipitation forms. No precipitate is onserved when a magnesium nitrate solution is added to a solution containing the unknown. What is the identity of the unknown compound? Explain reasoning

Kindly Please write the solution /calculation. Thank you.

a solution prepared by dissolving 0.2541g sample of electrolytic iron wire in acid was passed through a jones reductor. The iron (II) in the resulting solution required 36.76mL of the titrant Cr2O7 2-. What is the molar concentration of the Cr2O7- titrant?

- A 0.6842-g sample of potassium hydrogen phthalate was dissolved in 50 mL of deionized water and titrated to a phenolphthalein end- point with 17.28 mL of Ca(OH), solution. What is the molarity of the Ca(OH),?

A titration process is done by using 0.2M of 20 ml of third analytical group main reagent solution with 0.1 M nitric acid solution if nitric acid is replaced by sulphuric acid of same concentration, then the volume of sulphuric acid equals.... a. Half the volume of nitric acid b. Double the volume of nitric acid c. The volume of nitric acid d. Quarter the volume of nitric acid

Explain in four ways what happens when 25 mL of unknown AgNO3 in an Erlenmeyer flask is added with NaCl solution until no further AgCl precipitate is formed. Describe the reaction.

A 1.2516 gram sample of a mixture of CaCO3 and Na2SO4 was analyzed by dissolving the sample and completely precipitating the Ca2+ as CaC2O4. The CaC2O4 was dissolved in sulfuric acid and the resulting H2C2O4 was titrated with a standard KMnO4 solution. (a)        Write the balanced equation for the titration reaction, shown unbalanced below:                                     MnO4- + H2C2O4 + H+ ® Mn2+ + CO2 + H2O                         (i) Indicate which substance is the oxidizing agent and which substance is the reducing agent. (b)       The titration of the H2C2O4 obtained required 35.62 milliliters of 0.1092 molar MnO4- solution. Calculate the number of moles of H2C2O4 that reacted with the MnO4- (c)        Calculate the number of moles of CaCO3 in the original sample. (d)       Calculate the percentage by weight of CaCO3 in the original sample.

2. Solid lead(II) cyanide is slowly added to 125 mL of a 0.497 M ammonium phosphate solution until the concentration of lead ion is 0.0438 M. The percent of phosphate ion remaining in solution is %.

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A solution is known to contain 0.0150 M Ce(SO4)32-. When 25 ml of this solution is titrated, 23.44 mL of 0.032 M FeSO4 solution is required to reach the equivalence point. The reaction of the two substances produces Fe3+ as one of the products. Determine the oxidation number of Ce after the reaction.