--%>
Assignment Help - homework help

Help

1) Chromium(III) hydroxide is highly insoluble in distilled water but dissolves readily in either acidic or basic solution. Briefly explain why the compound can dissolve in acidic or in basic but not in neutral solution. Write appropriate equations to support your answer. 2) Explain how dissolving the Group IV carbonate precipitate with 6M CH3COOH, followed by the addition of extra acetic acid, establishes a buffer with a pH of approximately 5. 3) A solution contains either Cr3+ or Ni2+ ion. Describe the reaction with a single reagent that will identify which ion is present. 4) The addition of S2- ion to Fe(OH)2(s). Explain why the addition of S2- ion to Cr(OH)3(s) does not result in the formation of Cr2S3(s). 5) A black precipitate remaining from the separation of Cr3+ and Fe2+ ions from Ni2+ ion is dissolved in HCl HNO3. Some NH3 is added, followed by several drops of dimethylglyoxime. a) A colorless solution results. What do you think has happened? b) What might have gone wrong? 6) A student was analyzing an unknown containing only Group IV cations. When the unknown was treated with 3M (NH4)2CO3 solution, a white precipitate formed. Because the acetic acid bottle was empty, the student used 6M HCl to dissolve the precipitate. Following the procedure of this experiment, the student then added 0.10M K2CrO4 solution as directed and no precipitate formed. Oxalic acid was added to the solution, and no precipitate formed. a) What mistake did the student make? b) How did the mistake affect the tests for the cations in solution?

   Related Questions in Chemistry

  • Q : Problem on distribution law The

    The distribution law is exerted for the distribution of basic acid among: (i) Water and ethyl alcohol (ii) Water and amyl alcohol (iii) Water and sulphuric acid (iv) Water and liquor ammonia What is the right answer.

    		•
  • Q : Death cap musrooms the death cap

    the death cap mushroom based on your knowledge of the biochemistry of dna and rna

    		•
  • Q : Concentration of Sodium chloride

    Provide solution of this question. If 25 ml of 0.25 M NaCl solution is diluted with water to a volume of 500ml the new concentration of the solution is : (a) 0.167 M (b) 0.0125 M (c) 0.833 M (d) 0.0167 M

    		•
  • Q : Colligative property related question

    Select the right answer of the question. Which of the following is not a colligative property : (a) Osmotic pressure (b) Elevation in B.P (c) Vapour pressure (d) Depression in freezing point

    		•
  • Q : Analytical chemistry 37% weight of HCl

    37% weight of HCl and density is 1.1g/ml. find molarity of HCl

    		•
  • Q : Problem on colligative properties

    Choose the right answer from following. The magnitude of colligative properties in all colloidal dispersions is : (a) Lowerthan solution (b)Higher than solution(c) Both (d) None

    		•
  • Q : Explain the polymers and its types.

    Polymers are the chief products of modern chemical industry which form the backbone of present society. Daily life without the discovery and varied applications of polymers would not have been easier and colourful. The materials made of polymers find multifarious uses and applications in all walk

    		•
  • Q : What do you mean by the term medicine

    What do you mean by the term medicine dropper? Explain briefly?

    		•
  • Q : Explain methods for industrial

    The important methods for the preparation of alcohol on large-scale are given below:    

    		•
  • Q : Mass percent Help me to go through this

    Help me to go through this problem. 10 grams of a solute is dissolved in 90 grams of a solvent. Its mass percent in solution is : (a) 0.01 (b) 11.1 (c)10 (d) 9

    		•