Percentage purity

From the difference between the volume of 0.02M permanganate required to oxidise 50 mL of the iron(II) solution and that required to oxidise the iron(II) salt remaining after the addition of the persulphate, calculate the percentage purity of the sample. 

M.15 In addition to determining elemental composition of pure unknown compounds, combustion analysis can be used to determine the purity of known compounds. A sample of 2-naphthol, C)0H7OH, which is used to prepare antioxidants to incorporate into synthetic rubber, was found to be contaminated with a small amount of LiBr. The combustion analysis of this sample gave the following results 77.48% C and 5.20% H. Assuming that the only species present are 2-naphthol and I.iBr, calculate the percentage purity by mass of the sample. 

Suppose that 1.436 g of impure sodium hydroxide is dissolved in 300. mL of aqueous solution and that 25.00 ml. of this solution is titrated to the stoichiometric point with 34.20 mL of 0.0695 M HCl(aq). What is the percentage purity of the original sample ... 

A good number of pharmaceutical substances may be determined gravimetrically by obtaining their respective difficultly soluble salts as precipitates, weighing to a constant weight and finding the percentage purity of the substance in question. 

From above, the percentage purity of the given sample of NaCl may be found as shown below ... 

By incorporating the data given above, the amount of sodium chloride present in 100 g of the sample i. e., the percentage purity of NaCl in the given sample may be calculated as follows ... 

When the reaction occurs, the temperature of the hydrochloric acid rises from 14.5"C to 29.7"C. What is the percentage purity of the sample Assume that the specific heat capacity of the hydrochloric acid is 4.184 J/g°C. Also assume that all of the zinc in the impure sample reacts. 

The problem is centred around the comparison of two averages. That for the first percentage purity is 99%, while the average value for the four analyses reported is 98.73 with sn = 0.155. The pooled standard deviation of the two series of values is ... 

A 5.135 g sample of impure limestone (CaC03) yields 2.050 g of C02 (which was absorbed in a soda-lime tube) when treated with an excess of acid. Assuming that limestone is the only component that would yield C02, calculate the percentage purity of the limestone sample. 

The directions for the preparation differ from those for the preparation of sodium paraperiodate only in that 135 g. of potassium chlorate is used and 195 g. of pure potassium hydroxide. Since the latter always contains water, its percentage purity must be known. The yield is nearly 180 g. (98 to 99 per cent), and the purity is 99.5 per cent. 

To calculate the percentage purity from a dilution series, the lane in which the protein of interest is no longer visible is determined (Lm). Similarly, for each band of impurity, the lane in which it is no longer visible is determined (Li). 

The percentage purity of a sample describes what proportion, by mass, of the sample is composed of a specific compound or element. For example, suppose that a sample of gold has a percentage purity of 98%. This means that every 100 g of the sample contains 98 g of gold and 2 g of impurities. 

You can apply your knowledge of stoichiometry and percentage yield to solve problems related to percentage purity. 

You need to determine the percentage purity of the iron pyrite sample. 

Step 5 Determine percentage purity of the Fe2S using the following formula ... 

Determine the percentage purity of a reactant based on the actual yield of a reaction. 

After the reaction is complete, the solid barium sulfate, BaS04, is filtered and dried. Its mass is found to be 2.62 g. What is the percentage purity of the original barium chloride ... 

Ethylene gas obtained from 40 grams ethyl alcohol solution is saturated with 200 grams of Br2 solution, 5.6% by mass. What is the percentage purity of the ethyl alcohol solution ... 

When 5 grams of impure CaC2 is added to water, 1.12 L of acetylene is produced at STR What is the percentage purity of the CaC2 sample ... 

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