The decision of the test No. 1 of option 36 of the collection on chemistry Shimanovich I.E.
(formatted in Microsoft Word)
Tasks:
16. On oxidation of 16.74 g of a divalent metal, 21.54 g of oxide was formed. Calculate the equivalent masses of the metal and its oxide. What are the molar and atomic masses of a metal?
37. Write down the electronic formulas of atoms of elements with serial numbers 24 and 33, taking into account that the first has a "dip" of one 4s-electron to the 3d-sublevel. What is the maximum spin of d-electrons for atoms of the first and p-electrons for atoms of the second elements?
58. What is the modern formulation of the periodic law? Explain why in the periodic table of elements argon, cobalt, tellurium and thorium are placed respectively before potassium, nickel, iodine and protactinium, although they have a large atomic mass?
79. Draw an energy diagram of the formation of F2 molecules by the method of molecular orbitals (MO). How many electrons are in the bonding and antibonding orbitals? What is the bond order in this molecule?
100. Upon receipt of the equivalent mass of calcium hydroxide from CaO (k) and H2O (g), 32.53 kJ of heat is released. Write the thermochemical equation for this reaction and calculate the heat of formation of calcium oxide. Answer: -635.6 kJ
101. Calculate Go298 for the following reactions:
a) 2NaF (c) + Cl2 (d) = 2NaCl (c) + F2 (d)
b) PbO2 (c) + 2Zn (c) = Pb (c) + 2ZnO (c)
Is it possible to obtain fluorine by reaction (a) and reduce PbO2 with zinc by reaction (b)?
Answer: +313.94 kJ; -417.4 kJ
122. Write an expression for the equilibrium constant of the homogeneous system N2 + 3H2 2NH3. How will the rate of the direct reaction - the formation of ammonia - change if the hydrogen concentration is tripled?
143. To 3 liters of a 10% solution of HNO3 with a density of 1.054 g / cm3 was added 5 liters of a 2% solution of the same acid with a density of 1.009 g / cm3. Calculate the percentage and molar concentration of the resulting solution, the volume of which is 8 liters. Answer: 5.0%; 0.82 M
164. A solution containing 3.04 g of C10H16O camphor in 100 g of benzene boils at 80.714 ° C. The boiling point of benzene is 80.2 ° C. Calculate the ebullioscopic constant for benzene. Answer: 2.57 °
185. Make molecular and ion-molecular equations of the reaction of interaction in solutions between:
a) KHCO3 and H2SO4;
b) Zn (OH) 2 and NaOH;
c) CaCl2 and AgNO3.
206. What is the value of pH (> 7 <) have solutions of salts Na2S, A1Cl3, NiSO4? Make up the ionic-molecular and molecular equations for the hydrolysis of these salts.
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