Electrochemistry

1) What two metals are often used in electrochemical cells?

• Carbon and copper

• Zinc and sulfur

• Zinc and carbon

• Zinc and copper

An electrolytic cell uses electrical energy to drive

• chemical reaction

• physical reaction

• no reaction

• none of above

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-4

Galvanic cells convert

• mechanical energy in to electrical energy

• potential energy in to electrical energy

• electrical energy in to chemical energy

• chemical energy in to electrical energy

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-3

When water is electrolyzed, gas collected at cathode, is

• sulphur

• oxygen

• hydrogen

• sulphur dioxide

Tags

NGSS.HS-PS1-2

What reaction occurs at the anode?

Ag⁺/Ag = 0.80V

Ni²⁺/Ni = -0.25V

• Ag⁺ + e^- →Ag

• Ag → Ag⁺ + e^-

• Ni²⁺ + 2e^- → Ni

• Ni → Ni²⁺ + 2e^-

Tags

NGSS.HS-PS1-2

Which is correct to write cell notation

Anode: Zn

Cathode: Ni

• Zn²⁺ (aq,1M) / Zn (s) // Ni (s) / Ni²⁺ (aq,1M)

• Zn (s) /Zn²⁺ (aq,1M) // Ni²⁺ (aq,1M) / Ni (s)

• Zn²⁺ (s,1M) / Zn (aq) // Ni (aq) / Ni²⁺ (s,1M)

• Zn (aq) /Zn²⁺ (s,1M) // Ni²⁺ (s,1M) / Ni (aq)

Calculate standard cell potential for this equation:

Zn²⁺(aq) + 2e → Zn(s) Eº = – 0.76 V

Cd²⁺(aq) + 2e → Cd(s) Eº = – 0.40 V

• E^ocell = -0.36 V

• E^ocell = -1.16 V

• E^ocell = +1.16 V

• E^ocell = +0.36 V

State one functions of salt bridge

• to maintain the movement of electron

• to allowing electron to flow and complete the circuit

• to separate two electrolyte

• to maintain the electrical neutrality of the cell

Standard electrode potential of a half-cell is measured with reference to

• a) standard hydrogen electrode with 0.500M [HCl] solution

• b) standard oxygen electrode with 1.00M [HCl] solution

• c) standard chlorine electrode with 1.00M [HCl] solution

• d) standard hydrogen electrode with 1.00 M [HCl] solution

The cell potential of a spontaneous reaction is

• positive
• negative