Physical Chemistry Otázky

An endothermic process that perform work. |work| > |heat|

Heat is going to move from an object with a higher Temp (KE) to

A gas absorbs 55 kJ of heat and does 23 kJ of work. Calculate 🔺E.

Work is done on gas and the process is Exothermic |work| > |heat|

Work is done on a gas and the process is exothermic |work| < |heat|

Heat is the way in which thermal energy is transferred from a

Water boils in a kettle being heated on a stove.

Internal energy can be changes by two type of energy flow:

QUESTION:A voltaic cell is a system whose chemical reactions are _____ and results in generating an electric current.ANSWER OPTIONS:[A] : Exothermic[B] : Endothermic[C] : NON-spontaneous[D] : Spontaneous

QUESTION:Iron metal, Fe (s), undergoes a chemical reaction with oxygen, producing Fe2O3. In Fe2O3, the oxidation state of iron is +3. According to this information, iron was _____.ANSWER OPTIONS:[A] : Reduced[B] : Reduced and then oxidized[C] : Oxidized and then reduced[D] : Oxidized

QUESTION:Combine these half-reactions into a balanced overall redox reaction:Zn (s) → Zn2+ (aq) + 2 e−Ag+ (aq) + e− → Ag (s)ANSWER OPTIONS:[A] : 2 Zn (s) + 2 Ag+ (aq) → 2 Zn2+ (aq) + 2 Ag (s)[B] : Zn (s) + 2 Ag+ (aq) → Zn2+ (aq) + 2 Ag (s)[C] : Zn2+ (aq) + 2 Ag (s) → Zn (s) + 2 Ag+ (aq)[D] : Zn (s) + Ag+ (aq) → Zn2+ (aq) + Ag (s)

QUESTION:A voltaic cell is constructed using an aluminum electrode (submerged in Al(NO3)3) and an iron electrode (submerged in Fe(NO3)2). Aluminum is a stronger reducing agent than iron. Which choice correctly shows the half-reaction occurring at the cathode?ANSWER OPTIONS:[A] : Al3+ (aq) + 3e− → Al (s)[B] : Fe (s) → Fe2+ (aq) + 2e−[C] : Al (s) → Al3+ (aq) + 3e−[D] : Fe2+ (aq) + 2e− → Fe (s)

QUESTION:The surface of silver metal, Ag (s), became tarnished when it was exposed to oxygen, producing Ag2O. In Ag2O, the oxidation state of silver is +1. According to this information, silver metal was _____.ANSWER OPTIONS:[A] : Reduced[B] : Reduced and then oxidized[C] : Oxidized and then reduced[D] : Oxidized

QUESTION:When zinc metal is placed into a solution of Fe3+ ion, a redox reaction occurs producing Zn2+ ion and Fe2+ ion. Which is the correct half-reaction for illustrating the reduction portion of this redox reaction?ANSWER OPTIONS:[A] : Fe3+ (aq) + e− → Fe2+ (s)[B] : Fe2+ (s) → Fe3+ (aq) + e−[C] : Zn2+ (aq) + e− → Zn (s)[D] : Zn (s) → Zn2+ (aq) + 2e−

QUESTION:A voltaic cell was constructed using a zinc electrode (submerged in zinc sulfate), a copper electrode (submerged in copper(II) sulfate), and a salt bridge containing sodium sulfate. Given that zinc more easily forms cations than copper, which statement is false concerning this voltaic cell?ANSWER OPTIONS:[A] : Sodium ions from the salt bridge will migrate into the copper sulfate solution.[B] : Sulfate ions from the salt bridge will migrate into the zinc sulfate solution.[C] : Electrons flow from the zinc anode to the copper cathode.[D] : The mass of the anode increases over time.

QUESTION:A voltaic cell consisting of zinc and iron electrodes has this cell notation.Zn (s) | Zn2+ (aq) || Fe2+ (aq) | Fe (s)Identify the choice that correctly shows the reaction occurring at the anode as well as the overall reaction.ANSWER OPTIONS:[A] : The reaction occurring at the anode is Zn2+ (aq) + 2e− → Zn (s). The overall reaction is Zn (s) + Fe2+(aq) → Fe (s) + Zn2+ (aq).[B] : The reaction occurring at the anode is Fe2+ (aq) + 2e− → Fe (s). The overall reaction is Zn (s) + Fe2+(aq) → Fe (s) + Zn2+ (aq).[C] : The reaction occurring at the anode is Zn (s) → Zn2+ (aq) + 2e−. The overall reaction is Zn (s) + Fe2+(aq) → Fe (s) + Zn2+ (aq).[D] : The reaction occurring at the anode is Fe (s) → Fe2+ (aq) + 2e−. The overall reaction is Fe (s) + Zn2+(aq) → Zn (s) + Fe2+ (aq).

QUESTION:As shown here, some half-reactions have positive reduction potentials, some have negative reduction potentials, but only one has a potential of 0.00 V. What does a reduction potential of zero indicate about the hydrogen half-reaction?2 H+ (aq) + 2e− → H2 (s): [E° = 0.00 V]Ni2+ (aq) + 2e− → Ni (s): [E° = −0.23 V]Zn2+ (aq) + 2e− → Zn (s): [E° = −0.76 V]Hg2+ (aq) + 2e− → Hg (l): [E° = 0.85 V]ANSWER OPTIONS:[A] : It is always at equilibrium.[B] : Pairing it with another half-reaction prevents all electron transfer.[C] : It was arbitrarily chosen as the reference electrode.[D] : It can never be spontaneous.

QUESTION:When zinc metal is placed into a solution of Fe3+ ion a redox reaction occurs producing zinc ion and Fe2+ ion. Which is the correct half-reaction for illustrating the oxidation portion of this redox reaction?ANSWER OPTIONS:[A] : Zn2+ (aq) + e− → Zn (s)[B] : Fe3+ (aq) + e− → Fe2+ (s)[C] : Fe2+ (s) → Fe3+ (aq) + e−[D] : Zn (s) → Zn2+ (aq) + 2e−

color, shape, size, density, melting point, boiling point

Ability to react with oxygen (rusting) and flammability, change in pH are examples of?