What reactions belong to the oxidation-reduction?

2. ;

3. ;

4. Fe+S=FeS

A) 2, 4

B) 1, 3

C) 2, 3

D) 1, 4

E) 2, 1

299. What is the type of reaction: ?

A) Disproportion

B) Neutralization

C) Precipitate

D) Decomposition

E) Exchange

300. Oxidizer:

Accepts electrons;

Gives electrons;

Replaces protons;

Reduces enthalpy;

Absorbs warmth.

301. Reducer:

A) Gives electrons;

B) Accepts electrons;

C) Replaces protons;

D) Reduces enthalpy;

E) Absorbs warmth.

302. Oxidizer for the given reaction:

A) ,

B) ,

C) ,

D) ,

E)

 

303. Reducer for the given reaction: 4NH₃+3O₂=2N₂+6H₂O

A. N^-3

B. H⁺¹

C. O⁰

D. N⁰

E. O^-2

 

304. To specify the sum of coefficients for reaction:

A) 10

B) 8

C) 6

D) 2

E) 4

305. To specify the sum of coefficients for reaction:

А)20

Б)12

В)10

Г)14

Д)11

306. To specify the sum of coefficients for reaction: K₂S +K₂Cr₂ +H₂SО₄ S + K₂S0₄ + Cr₂ (SО₄ +

А) 26

Б) 20

В) 24

Г) 18

Д)22

 

307. To specify the sum of coefficients for reaction: +

A.7

B.8

C.6

D.5

E.3

308. To specify the sum of coefficients for reaction:

A) 13

B) 10

C) 9

D) 7

E) 14

309. To specify the sum of coefficients for reaction:

A) 19

B) 17

C) 14

D) 21

E) 13

310. To specify the sum of coefficients for reaction:

A) 7

B) 6

C) 4

D) 8

E) 5

311. To specify the sum of coefficients for reaction:

A) 22

B) 20

C) 18

D) 16

E) 14

312. To specify the sum of coefficients for reaction: →

A) 10

B) 8

C) 6

D) 4

E) 5

313. To specify the sum of coefficients for reaction: + + →Cr + + O

A) 14

B) 12

C) 10

D) 8

E) 6

314. pH of solution calculates according to the formula:

A) pH = 14 - pOH

B) pH = 14 + pOH

C) pH = K_gC + 10

D) pH = N/n

E) pH = n/N

315. The hydroxyl indicator of environment is equal:

^A) pH = [H⁺][OH^-]

^B) рОН = -lg[H⁺]

^C) [pОH = - lg[ОH^-]

^D) H₂O] = -lg[OH^-]

^E) pOH= -lg[H⁺][OH^-]

316. To specify an alkaline solution:

A) [H⁺] = 10^-12

B) [H⁺] = 10^-7

C) [ОH^-] = 10³¹

D) [ОH^-] = 10^-3

E) [H ₂О] = 10⁷

317. To specify a neutral solution:

A) H⁺] = [OH^-]

B) [H⁺] > [OH^-]

C) [H⁺] < [OH^-]

D) pH = 12

E) pH = 17

 

318. Electrolysis is:

A) oxidation-reduction process;

B) disintegration of a molecule of electrolit to ions;

C) process of association of ions;

D) movement of electrons around of nucleus;

E) process of molecule dissociation.

 

319. Cathode is an electrode at which there is a process:

A) Reduction of cations;

B) Oxidation of anions;

C) Disintegration of molecules;

D) Association of ions;

E) Changing of oxidation degree of an element.

320. Anode is an electrode at which there is a process:

A) Oxidation of anions;

B) Reduction of cations;

C) Disintegration of molecules;

D) Association of ions;

E) Changing of oxidation degree of an element.

321. E lectrolyte of the lead accumulator is the solution of:

A) H₂SO₄

B) H₂O

C) H₃PO₄

D) HF

E) HCI

 

322. Inhibitor is:

diminish of corrosion

corrosion accelerator

protector

accumulator

galvanic cell.

 

323. Faraday number is equal:

A) 96500

B) 73500

C) 760

D) 101

E) 83100

324. Potential of a standard hydrogen electrode is equal:

A) 0

B) 1

C) 2

D) 5

E) 9

325. To inert anodes belong:

A) graphite, platinum

B) zinc, copper

C) chrome, manganese

D) zinc, chrome

E) iron, zinc

326. To active anodes belong:

A) copper

B) platinum

C) neon

D) graphite

E) plastic

327. At electrolysis of NaCl solution at the anode it is allocated:

A) chlorine

B) sodium

C) oxygen

D) hydrogen

E) water