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1 If NaCl is dissolved in distilled water in a beaker the following item is formed

2 Drinking water

3 Electrons

4 An elementary strucutal unit of the substance is

5 Nuclides 16,8 O & 17,8 O & 18,8 O

6 Protium, deuterium and tritium

7 The maximum number of electrons in the shell with the principal quantum number n=2 is

8 Neutron

9 Ionic compounds

10 Cations are ions which

11 If both electrons of th covalent bond ar provided only by one atom, the bond is

12 A single covalent bond

13 A hydrogen bind

14 Hydrogen bonds are formed

15 Van der Waals forces

16 A molecule

17 Slect the correct stataement about hydroxides witht he general formula M(OH)n

18 The ionization energy

19 Th electron shell with the principal quantum number n=3 can contain

20 In the moleculed of Ch2 = Ch2 the followinf bonds are represented

21 A single bond

22 A double bond

23 According to the Brönsted theory,a cids are

24 According to the Brönsted theory, bases are

25 Which of the following paris are conjugated of the following protolytic reaction NH3 + HCl <-> NH4+ + Cl-

26 The strength of acids and bases

27 The solution is acidic if

28 The solution is alkaline

29 The solution is alkaline if

30 The solution is acidic if

31 If the acidity constant of the nitrous acid is 4.5x10^-4, (log 4.5 = 0.65) then the following statement is true

32 The ionization cinstant of the base

33 Protolytic reaction

34 The strong and weak bases differ

35 The value of the product of ion concentrations of H3O+ and OH- (Kw)

36 True solutions are

37 Which of the following statements about osmosis is true

38 An aqueous solution of AgNO3 (Mr = 170) at the concentration of 0.5 mol.l^-1 contains

39 There are three aqueous solutions: A(NiCl2), c= 0.1 mol.l^-1; B (KCl), c = 0.15 mol.l^_1; C (sucrose), c =0.3 mol.l^-1. Select the correct statement

40 There is a physiological solution of NaCl (c = 0.15 mol.l^-1). Slect the solution which is isotonic wiht NaCl solution

41 There is a Ba(NO3)2 solution with a concentration of 0.2 mol. Select a solution which is hypertonic compared to the Ba(NO3)2 solution

42 Diffusion

43 The physiological solution is the water solution of NaCl (Mr = 58) with a concentration of 0.15mol. It may contain

44 In a saturated solution of a salt

45 Osmosis

46 Oxidation

47 Reductions

48 Oxidising agents are substances

49 The chromium atom has the oxidation number VI in the following compounds

50 The oxygen atom has the oxidation number -I in the following compounds

51 The manganese atom has the oxidation number VII in the following compounds

52 The phosphorus atom has the oxidation number III in the compounds

53 Which of the following statements is true for the chemical reaction Zn + CuSO4 <--> ZnSO4 + Cu

54 Which of the follwoing statements is true for the chemical reaction Fe + 2HCl (diluted) —> FeCl2 + H2:

55 If we immerse pieces of iron and zinc in a solution of ferrous and zinx salts, the reaction proceeds

56 For the oxidation-reduuction reaction schemes, select the appropriate partial reactions or verify tthat the stoichiometric coefficients are corect:

Cu+ HNO3 —> Cu(NO3)2 + NO2 + H2O

57 For the oxidation-reduuction reaction schemes, select the appropriate partial reactions or verify tthat the stoichiometric coefficients are corect:

SO2 + H2S —> S + H2O

58 For the oxidation-reduuction reaction schemes, select the appropriate partial reactions or verify tthat the stoichiometric coefficients are corect:

Na2Cr2O7 +HCl —> NaCl + CrCl3 + Cl2 + H2O

59 The rate of chemical reaction

60 Chemical equilibrium of the reaction 2 HBr <—> H2 + Br2 with the reaction heat Qm = #70 kJ.mol is shifted to the reactant side by

62 The activation energy of the reaction

63 For the reaction 2NO2 <—> N2O4: Qm = 57 kJ.mol the following statement applies

64 According to Hess’s law the value of reaction heat "Qm of a given reaction

65 For the exothermic reactions following statements apply