Solution of the variant 48 KR №1 - chemisty Shimanovich

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Solution of test work No. 1 of option 48 of the collection of chemistry Shimanovich I.E

(formatted in Microsoft Word)

Tasks:

• 2.48 g of monovalent metal oxide contains 1.84 g of metal. Calculate the equivalent masses of the metal and its oxide. What is the molar and atomic mass of this metal?

• The isotope carbon-11 is formed when protons bombard the nuclei of nitrogen-14 atoms. Make the equation for this nuclear reaction and write it in abbreviated form.

• Based on the oxidation state of the atoms of the corresponding elements, give a motivated answer to the question: which of the two hydroxides is the stronger base: CuOH or Cu (OH) 2; Fe (OH) 2 or Fe (OH) 3; Sn (OH) 2 or Sn (OH) 4? Write the reaction equations proving the amphotericity of tin (II) hydroxide.

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

• Calculate the thermal effect and write the thermochemical equation of the combustion reaction of 1 mol of ethane C2H6 (g), which results in the formation of water vapor and carbon dioxide. How much heat will be released during the combustion of 1 m3 of ethane in terms of normal conditions? Answer: 63742.86 kJ.

• Based on the standard heats of formation and the absolute standard entropies of the corresponding "substances, calculate the Gо298 of the reaction proceeding according to the equation:

С2Н4 (g) 3О2 (g) = 2СО2 (g) 2Н2О (l)

Is this reaction possible under standard conditions?

Answer: -1331.21 kJ

• At a certain temperature, the equilibrium of the homogeneous system 2NO О2 2NO2 was established at the following concentrations of reactants: [NO] p = 0.2 mol / l; [O2] p = 0.1 mol / L; [NO2] p = 0.1 mol / L. Calculate the equilibrium constant and the initial concentration of NO and O2.

Answer: K = 2.5; [NO] ref = 0.3 mol / l; [O2] ref = 0.15 mol / l.

• 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

• How many grams of urea (NH2) 2CO should be dissolved in 250 g of water to raise the boiling point by 0.26 °? Ebullioscopic water constant 0.52 °. Answer: 7.5 g

• Make up the molecular and ion-molecular equations of interaction reactions in solutions between:

a) H2SO4 and Ba (OH) 2;

b) FeCl3 and NH4OH;

c) CH3COONa and HCl.

• Make up the ionic-molecular and molecular equations of hydrolysis of salts of NSOOK, ZnSO4,

A1 (NO3) 3. What is the pH value (> 7 <) have solutions of these salts?