Solution of the variant 15 KR №1 - chemisty Shimanovich

Solution of test work No. 1 of version 15 of the collection of chemistry Shimanovich I.E.
(designed in Microsoft Word)

Tasks:

15. An excess of hydrochloric (hydrochloric) acid affected the solutions:
a) calcium bicarbonate;
b) hydroxoaluminum dichloride.
Write the equations for the reactions of these substances with HCl and determine their equivalents and equivalent masses.

35. What values ​​can the quantum numbers n, l, ml and ms, characterizing the state of electrons in an atom take? What values ​​do they take for the outer electrons of the magnesium atom?

55. What are the lowest and highest oxidation states shown by silicon, arsenic, selenium and chlorine? Why? Draw up the formulas of the compounds of these elements corresponding to these oxidation states.

75. What forces of molecular interaction are called orientational, inductive and dispersive? When do these vultures appear and what is their nature?

95. The reaction of benzene combustion is expressed by the thermochemical equation:
C6H6 (l) + 7 1/2 O2 (g) = 6CO2 (g) + 3H2O (g); H =?
Calculate the heat effect of this reaction if it is known that the molar heat of vaporization of benzene is +33.9 kJ. Answer: -3135.58 kJ.

115. Based on the standard heats of formation and the absolute standard entropy of the corresponding substances, calculate the Gо298 of the reaction proceeding according to the equation:
CO (g) + 3H2 (g) = CH4 (g) + H2O (g)
Is this reaction possible under standard conditions? Answer: -142.16 kJ.

135. Calculate the equilibrium constant for the homogeneous system CO (g) + H2O (g) CO2 (g) + H2 (g) if the equilibrium concentrations of reactants are: [CO] p = 0.004 mol / l; [H2O] p = 0.064 mol / l;
[CO2] p = 0.016 mol / l; [H2] p = 0.016 mol / l. What are the initial concentrations of water and CO?
Answer: K = 1; [H2O] ref = 0.08 mol / l; [C0] ref = 0.02 mol / l.

155. What mass of HNO3 was contained in the solution if it took 35 cm3 of 0.4 N to neutralize it? NaOH solution? What is the titer of a NaOH solution? Answer: 0.882 g, 0.016 g / cm3

175. Calculate the percentage concentration of an aqueous solution of glucose C6H12O6, knowing that this solution boils at 100.26 ° C. Ebullioscopic water constant 0.52 °. Answer: 8.25%

195. Make up the molecular and ion-molecular equations of interaction reactions in solutions between:
a) CdS and HCl;
b) Cr (OH) 3 and NaOH;
c) Ba (OH) 2 and CoCl2.

215. Which salts of NaBr, Na2S, K2CO3, CoCl2 undergo hydrolysis? Draw up the ionic-molecular and molecular equations for the hydrolysis of the corresponding salts. What is the pH value (> 7 <) have solutions of these salts?