Химийн шалгалт

Тайлагдсан уусмал үүсгэх хослолыг тодорхойлно уу.

• A. CH3COOH/ CH3COO-, HCl/H+, HF/F-

• B. HNO3/H+, CH3COOH/CH3COO-, NH4OH/NH4+

• C. HCl/H+, HF/F-, HNO3/H+

• D. HF/F-, NH4OH/NH4+, CH3COOH/ CH3COO-

Which statement about the reaction involving the hydrated aluminum ion is true?

• A. H2O and [Al(H2O)5OH]2+ are a conjugate acid-base pair.

• B. H2O acts as an acid by donating H+.

• C. If OH- is added to the system, equilibrium will shift to the right.

• D. The pH will change depending on the conditions.

Using the given information, calculate the change in standard Gibbs energy for the reaction and predict whether it will occur spontaneously under standard conditions.

• A. 70.54 kJ/mol, will occur spontaneously

• B. -70.54 kJ/mol, will not occur spontaneously

• C. -70.54 kJ/mol, will occur spontaneously

• D. 70.54 kJ/mol, will not occur spontaneously

Arrange the following compounds in order of decreasing reactivity in a thermal reaction.

• A. b,a,d,c,e

• B. a,b,d,c,e

• C. e,d,c,b,a

• D. d,c,a,e,b

• E. d,e,a,c,b

For the galvanic cell using the half-cells Fe/Fe2+ (1M) and Pb/Pb2+ (1M): Fe2+ + 2e- = Fe 0.44V, Pb2+ + 2e- = Pb -0.13V, which of the following statements is correct?

• A. The mass of the iron electrode will increase as the cell operates.

• B. Electrons released from the lead electrode will flow through the external circuit.

• C. The concentration of Pb2+ ions will increase as the cell operates.

• D. The iron electrode will act as the anode.

• E. The concentration of Pb2+ ions will become zero when the cell is fully discharged.

What reaction is used to produce a rubber with high durability?

• A. polymerization

• B. polycondensation

• C. ring-opening polymerization

• D. addition

The blue color of cobalt chloride paper is associated with the ion [CoCl4]2-. What oxidation state does cobalt exhibit in this complex ion?

What oxidation state does cobalt exhibit in the complex ion [CoCl4]2-?

• Oxidation state +2

• Oxidation state +3

• Oxidation state -2

• Oxidation state +2

What explains that primary amines exhibit stronger basicity than ammonia?

• The nitrogen atom has lone pairs of electrons not involved in chemical bonding.

• Radicals of saturated hydrocarbons exert a push of electron pairs towards the nitrogen atom.

• The bond strength of N-H decreases.

• The polarity of the C-N bond decreases.

Calculate the number of atoms in 12.25L of hydrogen sulfide (H2S) at standard temperature and pressure.

• 4.5*10^23

• 6*10^23

• 9*10^23

• 12*10^23