Буклет 2015 року

Англійською мовою для іноземних студентів

Всього тестових завдань:
Вірних відповідей:

1. What method is used for quantitative determination of antituberculous drug isoniazid according to the regulations of the State Pharmacopoeia of Ukraine?

2. A patient came to a pharmacy and ordered cowberry leaves. Which of the available raw herbal materials can be offered as a substitute?

3. Injection solutions of weak acids and strong bases must be stabilized. What stabilizers are used for such solutions?

4. A 70-year-old patient with stenocardia claims that the pharmacy sold him a drug that relieved an attack of stenocardia but instead caused an acute bursting headache. What antihypertensive drug can be characterized by such a side effect?

5. Log books of stock-taking records are kept in a pharmacy for:

6. Specify the indicator which measures total contribution of various solutes to osmotic pressure of a solution:

7. What principle of goods and expenses accounting requires presenting results of business transactions within the same reporting period when the transaction occurs?

8. Companies producing injectable dosage forms apply different methods of ampoule sealing. Sealing against a jet of inert gases (nitrogen, argon, carbon dioxide) is suitable for the following injection solutions:

9. A dispensing chemist was addressed by a patient with the prescription of acetylsalicylic acid as antiaggregant. What daily dosage in grams should be recommended for him to take on a regular basis?

10. Simultaneous use of gentamicin and acyclovir tablets increases the risk of:

11. To make a liquid №2 by Demyanovych prescription hydrochloric acid should be taken in the following concentration:

12. An organisation has been founded to carry out several interconnected purposes. What type of organisation is it?

13. Select the reductant required for determination of arsenic impurity in drugs (method 2):

14. A pharmacy received a prescription for external use powder containing a substance difficult to pulverize. What liquid can be used by a pharmacist to disperse this substance?

15. A pharmaceutical company has made a decision to expand its activities. The process of the company’s activity expansion by penetration into new fields of the branch is called:

16. Preparations of common valerian are used in medical practice as sedative drugs. The main feature that allows to distinguish valerian from the admixtures is:

17. Business trip can be assigned to employees only with their consent, if these employees are:

18. Cash transactions at a pharmacy are recorded in the cashbook. Which of the following cash transactions IS NOT a receipt transaction?

19. Vitali-Morin’s reaction is used to identify tropane alkaloids in raw herbal material. Name the alkaloid that can be detected by this specific reaction.

20. A pharmacy makes infusion solutions. Specify the solution that restores water-salt metabolism.

21. A schedule of sanitation actions in pharmacies is regulated by the relevant normative documents. Cleaning day at a pharmacy must be scheduled for at least 1 time:

22. The following raw herbal material was delivered for analysis: capi-tulum inflorescence is semicircular or conic in shape; no pedicles or only their remains; floral disk is naked, conic, hollow. Semiflorets are white, disk florets are yellow, involucres are yellow-green. The smell is specific, aromatic. The taste is bitter-spicy. What raw herbal material is it?

23. Medications Passit and Novopassit are used as tranquilizing, sedative and mild soporific agents. These medications are produced from the following grass:

24. What final document is used for preparation of a report on the discrepancies revealed in the course of inventory taking at a pharmacy?

25. Phenobarbital drug has a sedative, soporific and anti-epileptic effect. What is its international nonpropri- etary name?

26. A patient suffering from bronchial asthma was diagnosed with essential hypertension. What antihypertensive drug is contraindicated for this patient?

27. What method is recommended by the State Pharmacopoeia of Ukraine for quantitative determination of potassium chloride substance that is used in treatment of hypokalemia?

28. Thyme grass is used for production of herbal medical products for treatment of respiratory tract infections. Under the State Pharmacopoeis of Ukraine, the raw herbal material is subject to chromatographic identification by means of thin-layer chromatography. What substances are detected on the chromatographic plate after its treatment with due reagent?

29. Specify the pricing strategy of international market, which foresees establishing relatively low prices to work up the developed countries market.

30. A new pharmaceutical enterprise is being founded. Which document of those given below is considered to be founding?

31. A pharmacy received a prescription for an alcohol solution of methylene blue with unspecified alcohol concentration. In this case a pharmacist must use ethyl alcohol of the following concentration:

32. What factors affect tablet disintegration?

33. What equipment is necessary to make trituration tablets?

34. When setting up a joint-stock company the founders discussed the issues of financial liability. What is the liability of the shareholders in a joint-stock company?

35. Which of the liquids given below should be measured by volume in making liquid dosage forms?

36. Nitrofural should be identified by chromatography according to the regulations of the State Pharmacopoeia of Ukraine. What type of chromatography is used for such identification?

37. During qualitative chemical analysis of nicotinic acid substance the reaction was conducted, which resulted in blue colouring. What reagent was used?

38. Preparations of sorrel roots can have both laxative and astringent effect. Such an effect results from the presence of the following biologically active substances:

39. Name the stage of drug life cycle that is characterized by maximal sales and profit, and reminder advertising.

40. Specify the reaction to identify ester-type drugs, which is required by the regulations of the State Pharmacopoeia of Ukraine:

41. A pharmacy has a license for selling narcotic drugs. The warrant for the receipt of these drugs from the pharmacy warehouse is valid for:

42. A pharmacy received a prescription for an extemporaneous compounded drug. Specify the document that is used to set the price for such drug:

43. A pharmacy received prescriptions for compound powders containing colouring agent. Which of powder components given below is a colouring agent?

44. Which of the penicillins given below can be identified by reaction with ninhydrin?

45. Coumarins are natural compounds with their structure based on an benzo-alpha-pyrone skeleton. What reaction allows to detect this group of compounds?

46. Quantitative content of theophylline can be determined by alkalimetric titration of nitric acid that is quantitatively exudated as the result of the following theophylline salt production:

47. Losartan is contraindicated for treatment of arterial hypertension in case of:

48. What physical constant of a substance can be used to identify diphenhydramine hydrochloride according to the regulations of the State Pharmacopoeia of Ukraine?

49. When a pharmacist was serving a customer who ordered a nonprecription drug he realized that the patient did not apprehend verbal information. Name the communicative barriers that arise when words or symbols may have different meanings for information sender and recipient:

50. Specify the normal spoilage ratio for toxic drugs, which should be taken into account by an inventory committee during stock-taking.

51. A pharmacist prepares a solution for injections that must be stabilized with 0,1M of hydrochloric acid solution. What solution is to be prepared?

52. Simultaneous use of doxycycli-ne hydrochloride and oral contraceptive causes:

53. One of the quality indicators for finished ampoules is lack of residual stress in the glass. Which operation at the "Preparation of ampoules to be filled"stage eliminates this imperfection?

54. A patient with osteoarthritis (gonarthrosis) and peptic gastric ulcer in anamnesis must be prescribed a NSAID (nonsteroidal antiinflammatory drug). What drug would be the most safe for this patient?

55. Which drug of the given below is a first aid antidote for acute poisoning caused by arsenic, mercury, chromium, and bismuth compounds?

56. An analytical chemist working at a pharmacy identifies oxacillin sodium salt. As a reagent he uses hydroxylamine hydrochloride solution in presence of sodium hydroxide solution and copper nitrate solution. What structural fragment of the drug molecule can be detected by these reagents?

57. Grass of yellow hornpoppy (Glaucium flavum) contains alkaloid glaucine. What pharmacological effect does this plant have because of this alkaloid?

58. Simultaneous use of paracetamol and acetylcysteine causes:

59. An analyst of the State Inspectorate for Quality Control identifies "Sulfametoxazol"by adding solutions of hydrochloric acid, sodium nitrite and beta-naphthol to the preparation. As a result intense red colouring is observed. What functional group is identified by this reaction?

60. Concentrated solutions CANNOT be used in mixturemaking if:

61. Calcium cations present in drugs can be detected with the following solution:

62. A pharmaceutical enterprise that has achieved high sales rates and customers’ recognition will reach the highest profit at the following stage of the product life cycle:

63. A pharmacist prepared a drug according to the following prescription: Rp.: Streptocidi Dermatoli ana 1,0 Lanolini Vaselini ana 5,0 M.D.S.: Apply to the affected skin. Specify the type of disperse system:

64. An ampoule workshop produces injection solutions. What filters are used for sterile filtering of injection solutions?

65. In case of simultaneous use of metronidazole and oral anticoagulants derived from coumarin patients must be warned about:

66. The risk can arise from some forms of activity connected with production of goods and services, their selling, commodity-money and financial operations, commerce, implementation of socioeconomic and scientific-and-technical projects. This is the definition of the following concept:

67. Prior to making a sodium chloride isotonic solution a pharmacist baked the powder in a dry heat box. What substances are removed by this operation?

68. Paracetamol substance has been sent for analysis. Reaction with the solution of iron (III) chloride resulted in blue-purple colouring. This indicates the presence of:

69. A pharmacist has prepared solution of ethacrydine lactate. Name the peculiarity of this substance dissolution.

70. Pharmaceutical market subjects that purchase drugs and medical products for further resale to make a profit, are called:

71. A pharmaceutical factory produces suspensions and emulsions. Specify the equipment that is used for dispersion and mixing in liquid medium:

72. A 59-year-old patient has been using furosemide for a long time to treat his cardiac insufficiency. What drug for hypokalemia prevention should be used in the given case?

73. According to the State Pharmacopoeia of Ukraine, in order to test a substance for the highest level of magnesium impurities an analytical chemist must use the following solution:

74. Stinging nettle (Urtica dioi-ca) leaves are mostly used as a hemostatic in tinctures and liquid extract to treat lung, intestinal, and uterine hemorrhages. What bioactive substance provides hemostatic effect?

75. Collective labour agreement is concluded by a trade union committee with an enterprise owner on behalf of the workforce. Any collective agreement is worked out in written form. Which article of the Labor Code regulates the duration of the collective agreement?

76. Products differentiation (advantages) pursued by a pharmaceutical company with the aim to surpass its competitors in satisfying customers’s demands is called:

77. A patient suffering from trombophlebitis of his lower extremities has developed symptoms of heparin overdosage. What drug can be used as an antidote?

78. To perform transactions with customers it is necessary for a pharmacy to have a cash register. What cash operation is registered by a cash register as a service payment?

79. When doing calculations to determine the limit of the cash balance, an accountant must specify the actual amount of cash receipts. What time period should be taken into account?

80. Drug A is in the stage of market saturation. In order to push up intensive sales, management of the manufacturing company decided to use the following type of advertising:

81. Name the way of injectabulettae application.

82. A patient with arterial hypertension and chronic bronchitis suddenly developed dry cough and dyspnea; his body temperature remained without changes. It is known that the patient takes captopril. This phenomenon can be explained by increased synthesis of:

83. A doctor wrote a prescription for the tincture of digitalis with hydrochloric acid. What is the reason for their incompatibility?

84. Who is responsible for reception of goods and medical products with simultaneous incoming quality control?

85. A 53-year-old woman suffers from ischemic heart disease and angina pectoris. What drug can be used to stop angina pectoris attacks?

86. The following fruit was received for analysis: succulent drupes circular or elongated-ellipsoid in shape, 4-12 mm in length. The colour of fruit varies from yellow to dark orange. The smell is faint. The taste is sour-sweet. What plant is it?

87. A pharmacy received a prescription for tincture. What raw herbal material can be used to make this dosage form?

88. A dispensing chemist can recommend a drug made from seeds of Aesculus hippocastanum to be taken as a veintonic and antithrombotic agent to treat venous congestion and veins dilatation of lower extremities. This drug is:

89. A patient suffering from moderately severe pneumonia was prescribed ceftriaxonum once a day. Prescription of ceftriaxonum once a day is due to the fact that the drug:

90. A pharmacist has made an althaea root tincture. What proportion of raw herbal material to extractant was chosen by the pharmacist to make this tincture?

91. What stage of drug life cycle is characterized by quick increase of its sales amount and customers’ recognition?

92. To stimulate sales a pharmaceutical wholesale company grants its customers a discount according to the social contract and on condition of their loyalty. Specify the type of discount:

93. A patient has chronic pancreatitis with apparent presentations of pancreatic exocrine hypofunction. Which of the following drugs would be the most advisable in this case?

94. Yellow gentian contains bitter glycosides. Raw material of this plant is recommended for production of drugs with the following effect:

95. Which of the pharmacy departments is responsible for checking the quantity and quality of received goods, their storage and dispensing to other departments?

96. Point out the type of group poll that foresees a single survey of several experts to discuss a certain problem.

97. A pharmacy makes bulk purchases of health and hygiene products. An agent works under a contract with a manufacturer and operates on his account. The agent may be given exclusive right to sell goods in certain regions. Specify this agent:

98. The common method for quantitative determination of drugs from the group of alkali metal halogenides is:

99. A patient, who has been taking acetylsalicylic acid, has developed hemorrhages of mucous membranes. This phenomenon is associated with:

100. A pharmacist makes powders with papaverine hydrochloride. What hand scales should be used for weighing out 0,05 g of substance?

101. Hexamethylenetetramine solution sterility is achieved by:

102. A patient is 20 years old. After she was stung by a bee the patient developed Quincke’s disease; rash in the form of blisters and papulae appeared on her torso. First aid in this case should start with administering the following drug:

103. A pharmacist worked on a holiday and his work hours were within the norm for the current month. The employee would be entitled to be paid:

104. Which of the following nonsteroid anti-inflammatory agents has the least harmful effect on mucosa of gastrointestinal tract?

105. Representatives of pharmaceutical companies have met to discuss urgent issues of their further work. This meeting belongs to the following type of organizational groups (teams):

106. A patient bought mint leaves at a pharmacy. What recommendations regarding infusion of this raw herbal material must be given by a pharmacist?

107. A manufacturing company initiates changes to the package insert of a drug aimed at limitation of its use. What type of marketing is used by the company in this case?

108. An analytical chemist determines the admixture of sulphates in boric acid. What is the main reagent to be added?

109. Specify which of the alkaloids given below will react positively to xanthines (murexide test):

110. Which of the drugs listed below is used for thrombolytic therapy of myocardial infarction?

111. The main method of quantitative determination of corticosteroids is:

112. When servicing customers it is necessary to maintain cash desk discipline. A cashier should make records in the cash book:

113. Ampoule workshop of a pharmaceutical factory produces procaine hydrochloride solution. This solution is stabilized by adding:

114. A pharmacy performs both cash and non-cash transactions. Financial intermediary in the latter is a:

115. An essential oil is a component of such compound drugs as: Inhalypt, Corvalol, Pinosol, Corvaldin, tooth drops. What raw herbal material is a source of this essential oil?

116. According to the law pharmacies have the right to paid leave. Total duration of main and additional leaves cannot exceed the following number of calendar days:

117. What technology should be chosen by a pharmacist to make a li- quid dosage form, if it contains calcium gluconate?

118. Point out the type of labour division structure of management personnel:

119. The basic structure of steroid hormones is hydrocarbon skeleton -cyclopentane perhydrophenanthrene. What natural compound is used for testosterone propionate production?

120. A pharmaceutical company conducted an age-specific segment analysis of the regional antihistamine market. It revealed the lack of antihistamines for children. The company will consider this segment as:

121. What department of a wholesale firm is tasked with search for and analysis of potential suppliers’ commercial offers, as well as concluding supply contracts and supervision of contract fulfillment?

122. Bellasthesin is a spasmolytic drug used in treatment of gastrointestinal diseases. What substance contained in Atropa Belladonna provides such an effect of the drug?

123. Plantaglucide is used to treat peptic ulcer disease of stomach and duodenum with normal acidity and hypoacidity. This drug is obtained from the following plant:

124. A pharmaceutical firm uses a set of marketing concepts to manage its interactions with consumers. Point out one of such concepts.

125. A pharmacist has prepared powders including extract of belladonna in the amount of 0,015 per dose. For ten doses he had to take the following amount of dry extract:

126. When developing the system of marketing communications, a company should consider the characteristics of each market promotion means applied for a drug. Which of the following characteristics is typical for advertising?

127. A patient has been administered a solution containing boric acid and camphor. What solvent should his doctor prescribe to prevent physical incompatibility?

128. A patient suffers from peptic ulcer disease. In the process of combined pharmacotherapy his feces became black. Name the drug that could be the cause of this.

129. A man with a long history of chronic hepatitis has been diagnosed with pneumonia. Which of the following antibacterial drugs can be applied in this clinical situation?

130. An analytical laboratory received "Adrenalini tartras"substance for analysis. According to the requirements of the Ukrainian State Pharmacopoeia, quantitative analysis of this substance can be carried out by the method of:

131. What preparation is the specific antidote in case of intoxication with iron preparations?

132. What ratio is used in making hawthorn tincture?

133. Standard raw herbal material of lily-of-the-valley is obtained by drying it at a temperature of 50-60°C in order to prevent the possibility of the following biochemical process:

134. A pharmacist has prepared a solution of menthol oil. Specify the dissolution temperature of the active substance:

135. Appropriate labor hours per week are being set for pharmacy staff. How many hours compose a working week for administrative staff?

136. A pharmacy received a prescription for vaseline-lanoline based eye ointment. What proportion of vaseline to lanoline should be chosen by a pharmacist to make the ointment base?

137. A pharmacy prepared a solution of macromolecular substance with limited swelling capacity. What solution was labelled "warm up before use"?

138. Granulation is used to increase:

139. Cumulating drugs - Digitoxin and Cordigitum - are used to treat chronic cardiac insufficiency. What plant is used as a raw material to produce them?

140. Complexometric titration (chelatometry) allows to determine quantitative content of:

141. Specify the norms of normal spoilage for medicinal leeches, which should be taken into account by a stock-taking committee.

142. Prescriptions for controlled drugs dispensed under the reimbursement program (except for narcotic and psychotropic preparations in substance) are issued on the following prescription form:

143. To increase hydrophobic suspension stability a stabilizer is added. Name this stabilizer.

144. According to the requirements of the State Pharmacopoeia of Ukraine (Addendum 1) a pharmacy analyst has to apply the following method for quantitative analysis of potassium iodide:

145. A teenager with hyporexia has been recommended to drink medicinal herbal tea of the following composition: Herba Absi-nthii, Herba Millefolii. Specify the characteristic microscopic features of Artemisia absinthium, which indicate its presence in the herb mixture:

146. A pharmacy performs regular stock-taking. What is the minimal interval between inventory checks of monetary funds and documents?

147. A pharmacy opens a bank account to store funds and conduct ongoing business transactions. What kind of account should be opened?

148. Which of the following diuretics SHOULD NOT be administered to patients with impaired hearing?

149. A pharmaceutical enterprise produces neogalenic preparations. What preparation is produced by the Soxhlet circulation apparatus?

150. A factrory workshop producing suspensions and emulsions is developing manufacture of new drugs. What mechanisms can be used for ultrasound production of drugs?

151. Admixtures can be accidentally included in raw herbal material in the process of harvesting, drying and primary processing. Mineral admixtures include:

152. Thymol is the main component of Thymus serpyllum essential oil. What is the time of harvesting for this raw herbal material?

153. What inventory holdings of a pharmacy are included by a committee in a separate inventory during stock-taking?

154. Quality of dried extracts is assessed according to several criteria. Specify the highest acceptable amount of moisture in dried extracts according to the State Pharmacopoeia of Ukraine.

155. A pharmaceutic factory workshop producing ointments can use the following equipment at the packing stage:

156. A retail pharmacy has been purchasing goods within an accounting period. What changes to the balance will result from these business transactions?

157. Menthol has anesthetic and antiseptic effect. What plant is the source of menthol?

158. A drug was delivered to a private pharmacy. The chemical name of the drug active ingredient is 2-chloro-10-(3’-dimethylaminopropyl)-phenothiazine hydrochloride. Specify this drug:

159. A set of values, traditions, behavioral norms and views inherent to an organisation characterize its following feature:

160. In the course of clinical instrumental examination a 45-year-old patient was diagnosed with chronic helicobacter-associated type B gastritis. What group of drugs should be prescribed first of all?

161. To identify a drug an analytical chemist of the State Inspectorate for Quality Control performs a lignin test. Specify this drug:

162. The main active components of hawthorn berries are flavonoi-ds. What is their pharmacological effect?

163. A pharmacy produces some injection solutions that have to be apyrogenic. Solution of the following substance can be depyrogenized by the method of adsorption with activated carbon:

164. Tyndallization is used at a pharmaceutical factory as one of sterilization methods for thermolabile substances. What is the essence of this method?

165. Theory of management currently specifies the four most important approaches to the management. Select the approach that IS NOT applied in the management theory:

166. Commercial and financial activity of a pharmacy involves using returnable packaging. Which of the following containers are returned to a supplier?

167. Apart from goods sales, there are other business transactions that can be characterized as goods disposal. Which of the following business transactions reduces stock at pharmacies?

168. Streptocide, sulfacyl sodium, norsulfazole or sulfadimezinum can be identified by the reaction forming the following substance:

169. Specify the base for antibiotic ointments:

170. A pharmaceutical company plans to produce hexamethylenetetram ne tablets. What production method is optimal for such tablets?

171. According to the regulations of the State Pharmacopoeia of Ukraine diphenylamine solution with sulfuric acid present can be used to detect the following admixtures in purified water:

172. What stage of drug life cycle is characterized by a period of slow increase of sales amount, significant expenses for demand making, and absence of profit?

173. A pharmacist has a labour dispute with the pharmacy administration about rescheduling his annual vacation leave. The employee can appeal against the decision of the pharmacy administration to the following body:

174. Chloride of lime is identified by calcium cations after boiling with acetic acid in order to eliminate acti- ve chlorine. What reagent is used?

175. What stage is the last in making injection solutions?

176. Specify the amount of raw herbal material necessary to make a dosage form according to the following prescription: Take 200 ml of motherwort herb solution. Dispense. Prescribed dosage is 1 tablespoon 3 times a day.

177. A 57-year-old patient is diagnosed with rheumatoid arthritis. Anamnesis states peptic ulcer disease. What nonsteroidal anti-inflammatory drug can be recommended for this patient?

178. A pharmaceutical factory produces herbal juice out of fresh raw herbal material. What operation should be performed at the stage of juice purification?

179. Which of the listed antibacterial drugs should NOT be admini- stered to a patient with diabetes mellitus type II being treated with glibenclamid?

180. Production of tablets requires stage-to-stage quality control. What devices are used to determine the particle size distribution (fraction) of granules?

181. A 46-year-old patient is diagnosed with cardiac infarction. What drug should be prescribed for thrombolytic therapy?

182. A laboratory received some raw herbal material for analysis. The plant had flowerheads up to 4 cm in diameter, marginal flowers were agamic, blue, funnel-shaped; the inner flowers were bisexual, purple, tubular. What plant has these features?

183. A pharmacist should make 200 ml of 3% sodium bicarbonate solution for injections. What are the specifics of making this solution?

184. Nitroxoline substance is being analysed for quantitative content of reactant by alkalimetry in non-water medium. What titrant and indicator are used in the given method?

185. Raw herbal material with the following features was delivered to a laboratory for analysis: fine flat glossy egg-shaped seeds (one end is sharp, other - rounded). Seed surface is smooth, vary in colour from pale yellow to brown, has pale yellow raphe. No smell is detected. The taste is slimy and oily. Name this raw herbal material.

186. Efficiency of aerosol therapy is to considerable extent determined by the size of disperse particles. What factor determines the size of aerosol particles during dispersion of an aerosol?

187. A 32-year-old woman that had been undergoing antibiotic therapy for her pneumonia has developed intestine disbacteriosis. What drugs should she be prescribed?

188. Activated carbon is used in production of injection solutions for:

189. During the analysis of diethyl ether (Aether medicinales) you can determine presence of aldehydes as a specific admixture. Which of the following reagents can be used for determining presence of aldehyde admixtures?

190. Intoxication cases were observed during harvesting raw herbal material containing potent and toxic substances. What raw herbal material SHOULD NOT be harvested by underage and pregnant?

191. A 20-year-old man suffers from chronic hyperacid type B gastritis. Choose the antisecretory agent.

192. What reagent is used to detect calcium admixture in medicinal substances?

193. According to the regulations of the State Pharmacopoeia of Ukraine the following solution is used to detect potassium admixture in medicinal substances:

194. A pharmacy performs stocktaking to check its inventory holdings. What is the minimal interval between inventory checks of fixed assets?

195. Preparations containing cardi-osteroids are produced out of the following raw herbal material:

196. A pharmaceutical firm is unable to satisfy the demand for a drug. Specify the type of marketing tasked with decrease of excessive demand for a product by raising prices, and stopping advertising and promotion.

197. What is the function of anhydrous lanolin in the suppository mass used for suppositories made by hand rolling?

198. A patient with heart failure induced by long-term coronary vessel disorder can be administered a drug produced out of the following raw herbal material:

199. Choose the substance that is a tropane-derived alkaloid:

200. Pharmaceutical analyst working at the laboratory of the State Inspectorate for Quality Control of Medicines identifies the drug substance "Glucose anhydrous"with copper-tartrate solution (Fehling’s reagent). What is the colour of produced precipitate?