Production of Zinc Sulphate

Stability And Reactivity:

Uses of zinc sulphate:

1. It is used to preserve fish skin.
2. It is used as a catalyst.
3. It is used as antalkali in printing and dyeing.
4. It is used as raw material for production of inorganic pigments (such as lithopone).
5. Other zinc salts such as zinc stearate and zinc carbonate are used as preservatives for wood and leather.
6. It is used as raw material for production of lithopone and in synthetic fibre industry.
7. It is used in zinc plating.
8. It is used as a raw material in making pesticides and as a weed killer in agriculture.
9. It is used in making trace element fertilizer and feed addictive.

Hazards Identifications:

POTENTIAL HEALTH EFFECTS

Effects of Short-Term (Acute) Exposure

 Inhalation: 

Dusts or mists (solutions) are probably non-irritating or mildly irritating. No human information is available, but inhaled zinc sulphate caused no observable toxic effects in animal tests. Reversible loss of the sense of smell may occur, based on data from animal tests.(2)

Skin Contact: 

Zinc sulphate is not likely to cause irritation to the skin.

Eye Contact: 

Zinc sulphate is moderately irritating to the eyes (3), but damage is normally reversible.(9) Dilute solutions of zinc sulphate have been used as astringent eye drops.(4)

Ingestion: 

Low doses of zinc salts are probably not toxic by ingestion. An excess of zinc salts can cause vomiting, burning sensation in the throat and stomach, followed by abdominal pain, bloody diarrhoea, convulsions, changes in blood pressure and coma. Death may ensue after ingestion of a few grams, although the emetic effect of zinc sulphate (typically 0.6 to 2 g) makes severe poisoning unlikely.(3,13)

First aid Measures:

Inhalation: 

If symptoms are experienced, remove source of contamination or move victim to fresh air. Obtain medical advice immediately.

Skin Contact: 

If irritation occurs, as quickly as possible, flush contaminated area with lukewarm, gently running water for at least 10 minutes, by the clock. Remove contaminated clothing, shoes, and leather goods (e.g., watchbands, belts). If irritation persists, obtain medical advice immediately. Completely decontaminate clothing, shoes and leather goods before re-use or discard.

Eye Contact: 

Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for 20 minutes, by the clock, holding the eyelid(s) open. If irritation persists, repeat flushing. Obtain medical advice immediately.

Ingestion: 

Never give anything by mouth if victim is rapidly losing consciousness, or is unconscious or convulsing. Have victim rinse mouth thoroughly with water. DO NOT INDUCE VOMITING. Have victim drink 240 to 300 mL (8 to 10 oz.) of water. If vomiting occurs naturally, rinse mouth and repeat administration of water. Obtain medical advice immediately. NOTE: Zinc sulfate is an emetic (can induce vomiting).

First Aid Comments: 

           Consult a physician and/or the nearest Poison Control Centre for all              exposures except minor instances of inhalation or skin contact.
All first aid procedures should be periodically reviewed by a physician familiar with the material and its conditions of use in the workplace.

Equipments:

1. Bunsen burner
2. Evaporating dish
3. Gauze
4. Tripod stand
5. Zinc oxide (28 crystals)
6. Zinc hydroxide (28 crystals
7. Zinc carbonate (28 crystals
8. Sulphuric acid  (1 mole)

Safety:

1. I will wear protective goggles to prevent my eyes.
2. I will open all windows for good ventilation.
3. I will not inhale Zinc Sulphate.
4. I will be careful when boiling the sulphuric acid because it can boil and bubble down.
5. Sulphuric acid is corrosive and irritant so I will be careful with my skin.

Planning:

1. I will keep the amount of sulphuric acid the same 1 mole for all the experiments.
2. I will work with the same amount of all types of Zincs.
3. I will remove the Sulphuric acid immediately when it boils.

Method with Zinc oxide (Zno):

  Firstly I put 1 mole of sulphuric acid on an evaporating dish and heated it and waited for it to boil. When it boiled, I stopped heating and waited for it to cool. When it cooled, I added Zinc oxide. I stopped adding Zinc oxide when reaction stopped. I waited for the solution to cool and I dried it with a paper. After drying the solution was Zinc sulphate.

 

Diagram:

Equation:

    Zinc oxide + Sulphuric acid ➔ Zinc Sulphate + Water

       Zno        +     H2so4         ➔        Znso4     +    H2o

Observation:

       I saw fumes being produced.

Method with Zinc Carbonate (Znco3):

    Zinc carbonate is highly reactive so, I did not boil sulphuric acid. I put 1mole of sulphuric acid to an evaporating dish. Then I added Zinc carbonate till it stopped reacting. I waited for the solution to cool and I dried it with a paper. This is Zinc sulphate.

Diagram:

Equation:

Zinc carbonate + Sulphuric acid ➔ Zinc Sulphate + Water + Carbon dioxide

       Znco3      +     H2so4         ➔        Znso4     +    H2o + Co2

Observation:

I saw fumes being produced.

Method with Zinc hydroxide (ZnoH):

  I did not have Zinc Hydroxide so I made my own by adding water to Zinc Oxide which gave Zinc Hydroxide solution. Then I boiled 1 mole of Sulphuric acid and then I added ZnoH solution. I waited for the solution to cool. I poured the cooled solution to a paper to dry. This is Zinc sulphate.

Diagram:

Equation:

Zinc Hydroxide + Sulphuric acid ➔ Zinc Sulphate + Water + Hydrogen

       ZnoH      +     H2so4         ➔        Znso4     +    H2o + H

Observation:

 I saw fumes being produced.

Calculating the yield:

Calculating the percentage yield

Formula: 100% yield == mass of crystals made x 100

                                                          14

Mass of crystals= 28

== 28 ÷ 14 x 100 == 200%

Calculating the actual yield

                    Formula:  Actual yield x 100 

                                     Theoretical yield

          28 ÷ 14= 2

          2 ÷ 14= 0.14…

          0.14x 100= 14g

Conclusion:

     My prediction was correct because in this experiment I have found out that Zinc Oxide is the best chemical to use while producing 14g zinc sulphate. This is because I boiled the sulphuric acid and reacted quickly. I did not boil the sulphuric acid while combining it with Zinc Carbonate because it is highly reactive. This can cause the product I will get to be under 14g because I don’t know how much water evaporated.

Evaluation:

   Although my experiment was successful, I believe that there are a few changes which can be made to make it truer. I did not dry the solution I got because I did not have enough time. If I was to do this experiment again, I will wait for the solution to dry and see the amount of zinc sulphate produced. I would also time the reaction to see the reaction rates of the chemicals I use.