The decision of the test No. 1 of option 54 of the collection of chemistry Shimanovich I.E.
(formatted 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.

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?

59. What are the lowest and highest oxidation states of carbon, phosphorus, sulfur and iodine? Why? Draw up the formulas of the compounds of these elements corresponding to these oxidation states

61. What chemical bond is called covalent? How can you explain the directionality of the covalent bond? How does the method of valence bonds (VS) explain the structure of a water molecule?

84. When gaseous hydrogen sulfide and carbon dioxide interact, water vapor and carbon disulfide CS2 (g) are formed. Write the thermochemical equation for this reaction by calculating its thermal effect. Answer: +65.43 kJ

105. The entropy decreases or increases during the transitions: a) water into steam; b) graphite to diamond? Why? calculate Sо298 for each transformation. Make a conclusion about the quantitative change in entropy during phase and allotropic transformations. Answer: a) 118.78 J / (mol • K); b) -3.25 J / (mol * K).

124. The reaction proceeds according to the equation N2 + 3H2 = 2NH3. The concentrations of the substances involved in it were: [N2] = 0.80 mol / l; [H2] = 1.5 mol / L; [NN3] = 0.10 mol / L. Calculate the concentration of hydrogen and ammonia when [N2] = 0.5 mol / L. Answer: [NH3] = 0.70 mol / l; [H] = 0.60 mol / l.

141. Calculate the molar and equivalent concentration of a 20% solution of calcium chloride with a density of 1.178 g / cm3, Answer: 2.1 M; 4.2 n

162. Calculate the percentage concentration of an aqueous solution of sugar С12Н22О11, knowing that the crystallization temperature of the solution is -0.93 ° C. The cryoscopic constant of water is 1.86 °. Answer: 14.6%.

184. Which of the substances: Al (OH) 3; H2SO4; Ba (OH) 2 - will interact with potassium hydroxide? Express these reactions with molecular and ionic-molecular equations.

214. When mixing solutions A12 (SO4) 3 and Na2CO3, each of the salts taken is irreversibly hydrolyzed to the end with the formation of the corresponding base and acid. Draw up the ionic-molecular and molecular equations of the ongoing joint hydrolysis.