CHEMICAL TESTS 2 RIU TANTAL

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CHEMISTRY
Question 1. Every pure substance, regardless of the method of making it and being in nature, has a constant qualitative and quantitative composition.
1) The law of simple volume ratio.
2) The law of Avogadro.
3) The law of definite proportions.
4) The law of simple multiple proportions.
5) The law of equivalents.

Question 2.Edinitsa amount of substance -
1) molecule
2) Atom
3) Equivalent
4) Mole
5) Ion.

Question 3. The valence electrons of an atom layer of gallium - Ga:
1) 3s2p2
2) 3dl04s'
3) 4s2p '
4) 3d'4s2
5) 4s2p2

Question 4. The quantum numbers describing a) orbital shape, b) the direction of the electron clouds in space:
1) a) l, b) / m I
2) a) n, b) l
3) a) m I, b) t S
4) a) n, b) m I
5) a) m I, b) l

Question 5: In the molecule of a substance from the central atom holds sp2 - hybridization?
1) BC13
2) C2H2
3) VeSl2
4) H2SO4
5) SF6






Circle one s and two p orbitals involved in the formation of molecules BCl3.

Question 6. Links are located in the order of increasing strength:
1) H-Cl, HF, H-Br
2) HF, H-C1, H-Br
3) H-Br, HF, H-C1
4) H-Br, H-Cl, HF
5) H-Cl, H-Br, HF.

Question 7: At absolute zero, the entropy of all bodies is 0.
1) Hess
2) Periodic Law
3) The first law of thermodynamics law
4) The second law of thermodynamics
5) The third law of thermodynamics.

The value of an additive constant that arises in the determination of entropy set Nernst theorem, which is often called the third law of thermodynamics: entropy of any system at absolute zero can always be taken as zero

Question 8. The heat of reaction Cu2 ++ Mg ° = Mg2 ++ Cu ° is 534 kJ. What is the amount of heat released during the restoration of 12.8 g of copper?
1) 1068 kJ
2) 10.68 kJ
3) 106.8 kJ
4) 213.6 kJ
5) 53.4 kJ

The number of moles of copper is equal to 12.6 / 64 = 0.2 mole. (64 is the atomic mass of copper) then if the thermal effect of the conversion of one mole of copper equal to 534 kJ in the reaction of 0.2 mol of the thermal effect will be 534 * 0.2 = 106.8 kJ

Item 9. If the hydrogen concentration reduced to 3 times the rate of reaction 2H2 + O2 = 2H2O ...
1) a 2-fold increase
2) 9-fold increase
3) 3-fold decrease
4) decreased 9-fold
5) increased 3-fold.

The reaction rate expressed by the equation V = [H2] 2 [O2]. Then, if the hydrogen concentration is reduced to 3 times obtain V = [1/3] 2 [1] = 0.11, that is the rate of the initial amount of 0.11 or 1 / 0.11 = 9 times.

Question 10: In what direction will shift the balance in the system H2 + I2 = 2NI; -an At a) increasing the temperature, b) decreasing the concentration of HI?

Exothermic reaction as the proceeds with heat release (-an). Therefore, according to the principle of Le Chatelier increasing temperature shifts the reaction equilibrium towards the reaction runs with heat absorption, i.e. in the direction of the reverse reaction (to the left). Lowering the concentration HI will shift equilibrium to the right, since the removal of the reaction product always entails shifting the equilibrium toward products.


1) a) b)
2) a) b)
3) a) b)
4) a) b) ???????
5) a) b)

Question 11. Which of the following reactions in electrolyte solutions are going to end?
1) ZKON + A1 (OH) 3 = K3 [A1 (OH) 6]
2) HNO3 + NaOH = NaNO3 + H2O
3) MgS + 2HCl = H2S + MgCl2
4) All of the above
5) There is no right answer


Additional information

Q12 which medium and what pH in a solution containing 5.10- 4 mol / l of H +?
1) alkaline, pH = 3, 30
2) acidic, pH = 4.70
3) alkaline, pH = 4.70
4) a neutral, pH = 7
5) acid, pH = 3.30

pH is calculated by the equation pH = -log [H +] = -log 5.10- 4 = 3.30. pH less than 7 is acidic so

Question 13. What is the level of oxygen in the oxidation of H2O2? What may be a hydrogen peroxide redox reactions?
1) -2, the reducing agent
2) -1, oxidant and reductant
3) -2, the reducing agent and oxidizing agent
4) - 1, the reducing agent
5) 2, an oxidizing agent.

Question 14. Specify the products of electrolysis solution of Pb (NO3) 2: 1) H2 O2
2) Pb, N2, O2
3) H2, Pb (OH) 2
4) Pb, O2, HNO3
5) H 2, Pb (OH) 2, HNO3, O2.

Question 15. Specify the corrosion products contact Mg-Cu in a neutral environment: l) Mg2 +, H2
2) Cu2 + H2
3) Mg (OH) 2
4) Cu (OH) 2
5) Mg (OH) 2, H2.

Scheme galvanic couple Mg / O2, H2O / Cu,

an anode (Mg): Mg0  2 = Mg2 +,
a cathode (Cu): O2 + 2H2O + 4 = 4OH-,

The overall reaction and the product is: Mg2 + + 2OH- = Mg (OH) 2.


Question 16. To what point and under the bar) is metal, is dissolved in concentrated HNO3, under paragraph b) metal is dissolved in KOH? Write the equations reactions.
1) a) Au b) Cr
2) a) C, b) Au
3) a) C b) Cr
4) a) Cr, b) C
5) a) Au, b) C

Cu + 3HNO3 (conc) = Cu (NO3) 2 + NO2 + H2O
2Cr + 2KOH + 6H2O = 2K [Cr (OH) 4] + 3H2

Question 17. In the half-reaction equation MnO2 + 4ON -... MpO4- + 2H2O number cast (made) of electrons is equal ... MnO2 is ...
1) 3 e, a reducing agent
2) -Ze- reducing agent
3) + 2e, oxidant
4) -2e- reducing agent
5) + 3e- oxidizing agent.

Vopors18. The coordination number and charge of the ion-complexing agent in the compound [Pt (NH3) 4Cl2] respectively:
1) 2 + 2
2) 3, 4
3) 6, 3
4) 6 + 6
5) 6 2


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