Sulphuric Acid Production by Dcda Process

* In the process of mining coal, the useful energy output is in the form of chemical energy.

In this task the concentration of an unknown sample of copper sulphate using colorimetry was used to find the concentration. In this investigation copper sulphate was used which is CuSO4.5H20 as a formula. To make a standard solution which was 1M, the same clean equipment was used to make up the standard solution as used to make sodium carbonate. However there was one difference and that was that the hot distilled water was used to dissolve the copper sulphate crystals. There had to be enough hot water in order to dissolve the crystals into the beaker and then add cold distilled water to cool the solution.

sodium thiosulphate + hydrochloric acid = sodium chloride (salt) + sulphur + water + sulphur dioxide

This reaction is exothermic, meaning it releases heat when reactants are converted into products. The negative change in enthalpy (∆H° = -36,757 J) for this reaction indicates that the reaction is losing heat to its surroundings.

Then 8.0g of copper sulfate crystals were placed inside the beaker and the mass was recorded for the actual crystals. 50 mL of water was added to the beaker with the crystals. The ring stand was set up with the wire mesh on it and one partner should place the mixture in the beaker on it should be heated without letting the mixture boil. Stir the mixture and heat until the crystals are dissolved. While one partner does this, the other should obtain 1.5g of iron filings in a measuring cup and records the mass. Then the iron filings should be added small amounts at a time to the heated solution. Stir continuously until all the mixture is added to the beaker. Then it sat for 10 minutes and observations were recorded. Record the mass of a filter paper and set up a filtration apparatus with the filter paper in a funnel over an Erlenmeyer flask. Decant the liquid through the paper slowly trying not to allow any solid to get on the filter paper. Then with de-ionized water, rinse your solid in the beaker and let the solid settle then decant the liquid. Repeat the washing twice more and in the last time guide all the solid into the filter paper. Then place the filter paper on a watch glass and then into a warm oven to dry. After it is cool, record the mass of the watch glass, filter paper and solid. If there is not enough time to cool, you may have to do it the next

Sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and Egypt. In the Bible, burning sulfur was referred to as “brimstone” and Hell was considered to “smell of sulfur”. Ancient Egyptians used sulfur in an ointment that treated granular eyelids. In ancient Greece it was used as a form of fumigation, that is mentioned in the Odyssey. A natural form of sulfur known as “shiliuhuang” was known in China since the 6th century BC and by the 3rd century BC it was used as a form of medicine. In 1044 AD, the Chinese military used sulfur in black powder. It was a mixture of potassium nitrate (KNO3), charcoal, and sulfur. Today it still remains an ingredient of black powder. Indian alchemists wrote about the use of sulfur in alchemical operations with mercury from the 8th century AD

Seven test tubes were labeled numerically with 2 mL of VO3- and H2SO42- added to each tube. A small pea size portion of solid Na2SO3 was added to the first test tube. Then, 20 drops of distilled water were added to the second test tube. In the third test tube, 20 drops of (.2 M) NaBr were added. Then, to drops of (.2 M) NaNO2 were added into the fourth test tube. A small portion of Fe(NH4)2(SO4)2 * 6H2O was added into the fifth test tube. The sixth test tube had 20 drops of (.2 M) H2Cr2O4 added, where the seventh test tube was the control tube with no additional chemicals added. All the test tubes were left to react for 3 minutes and then heated in a heated bath for approximately 20 minutes.

In part I, the ΔH of each individual reaction was obtained by performing each reaction inside a calorimeter. Temperature probes were inserted in the calorimeter and ΔT was measured. By using the equation q = Msol’n x Cp x ΔT + Ccal x ΔT, the heat absorbed by the surroundings, q, was obtained for each reaction. The negatives of these values, or heat released by the

If the solid phase temperature is high enough (above 900 °C), the in-situ reforming will occur. In this condition, the natural gas reacts with CO2 and H2O to produce H2 and CO. The following reactions are

In the process roasting there is a change in some of the CuFeS2 to copper oxide remove some of the sulphur as sulphur dioxide. This is done by heating the concentrated chalcopyrite ore from froth floatation. It is heated to between 500 °C and 700 °C in air. From the roaster a product is formed called a calcine, which is a solid mixture containing oxides, sulphides and sulphates. SO2(g) is released from the copper minerals. This is a important and valuable by product of the process and helps to offset the costs of copper

The lab performed required the use of quantitative and analytical analysis along with limiting reagent analysis. The reaction of Copper (II) Sulfate, CuSO4, mass of 7.0015g with 2.0095g Fe or iron powder produced a solid precipitate of copper while the solution remained the blue color. Through this the appropriate reaction had to be determined out of the two possibilities. Through the use of a vacuum filtration system the mass of Cu was found to be 2.1726g which meant that through limiting reagent analysis Fe was determined to be the limiting reagent and the chemical reaction was determined to be as following:-

* This system was designed to help stop the reaction if too much heat was generated.

When the zinc was added to the copper (II) sulfate solution, the solution started to bubble. As the solution was stirred, it turned a cloudy blue. Small flecks of a brown solid were visible. As the solution became colorless, the brown solid settled to the bottom of the beaker. The solid formed was copper in its elemental state. The color faded from the solution as the copper ions slowly formed into solid copper. The copper was poured into a funnel with filter paper and washed three times with 25 mL

Two catalyst reactants are used in the experiment, thiosulfate and starch, to dictate the time of reactions.

For the displacement reaction, an excess amount of zinc powder is added to the measured amount of aqueous copper (II) sulphate. The temperature change over a period of time has to be measured and thus, the enthalpy change for the reaction can be measured.