Аnalytical chemistry
Аnalytical chemistry
Питань: 25
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Питання 1 з 25
Питання 1
A heated nichrome wire was immersed in the solution that is being studied and then placed in the flame of a gas burner. The flame colored yellow-green as a result. What cations are present in the solution?
Питання 2
What reagent must be used for identification of sodium cations in a sodium thiosulfate substance according to the regulations of the State Pharmacopoeia of Ukraine, second edition?
Питання 3
An alkali was added into the solution being analyzed. When heated, the solution produced a gas. This gas changes the color of a moist litmus paper from presence of the following ions in the solution:
Питання 4
What titrimetric method of analysis can be used to determine the total content of CaCl2 and NaBr in a solution?
Питання 5
What anions are present in the solution, if it colors violet when iron (III) chloride reagent is added into it?
Питання 6
What method is used for quantification of bismuth in a preparation?
Питання 7
What type of chromatography does the gas-liquid chromatography method belong to?
Питання 8
Laboratories and factories use selective solvents to isolate and purify essential oils, alkaloids, antibiotics, and other medical substances. This method can also be used to isolate a pure substance from the reaction mixture or to continuously remove one of the reaction products from the reaction mixture in the process of synthesis. What is the name of the described method?
Питання 9
Sulfanilamides contain a primary aromatic amino group in their structure. What method is used for quantification of these compounds?
Питання 10
To determine the qualitative content of a drug, a sample of the analyte solution was processed with 2M solution of HCl. A white precipitate, soluble in aqueous ammonia solution, formed as a result. The presence of which cations does this analytical effect indicate?
Питання 11
What value determines the degree to which extraneous ions have an effect on the potential of the ion-selective electrode?
Питання 12
What method of titration is used, when a precisely measured excess of the auxiliary titrant is added to the solution of the analyte substance?
Питання 13
Thiocyanatometric titration method requires secondary standard solution of potassium thiocyanate that is standardized with standard solution of:
Питання 14
Pharmacopoeia reaction to determine benzoate ions requires interaction with the solution of:
Питання 15
Choose the indicator and titration method to determine hydrogen carbonate ions in a drug:
Питання 16
Hydrochloric acid was added into the solution under investigation. The resulting precipitate was filtered, then this filter cake was processed with hot water; after the filtrate cooled, KI solution was added into it. What cation was present in the solution if the precipitate was colored yellow?
Питання 17
Permanganametometry is a titrimetric method for the determination of substances based on oxidation reactions involving
permanganate ions. Which of the following are the standard solutions that are used according to this method for the quantitative determination of oxidants by reverse titration method?
Питання 18
The researcher while conducting the qualitative analysis that involves sulfates precipitation of the third analytical group
cations (Ca2+, Sr2+, Ba2+) has to reduce solubility of sulfates. What substance should he use for this purpose?
Питання 19
In the process of systematic analysis there is a need to separate PbSO4 from mixture of the 3rd analytical group cation sulphates. Which of the following suits most towards this end?
Питання 20
In order to carry out the silver cations identification, HCl was added to the solution. Later, the formed solution was
followed by adding the solution of ammonia. Specify which of the below-mentioned compounds are formed in such case?
Питання 21
Ammoniacal buffer and 8oxyquinoline solution were added into the solution containing cations of the V analytical group, which resulted in production of a green-yellow precipitate. What cations were in the solution?
Питання 22
A specialist of the analytical laboratory performs direct iodometric determination of ascorbic acid. What indicator is used in this case?
Питання 23
Quantitative content of hydrogen peroxide can be determined by means of the following self-indicator method:
Питання 24
Name the reactions and reagents that under certain conditions allow determination of certain ions in the presence of other ions:
Питання 25
How according to the Pharmacopoeia is pH determined?