SSS IITM Quiz

In an electrochemical cell, consisting of C anode and Pt cathode. The following reaction occurs at the electrodes
At cathode: 2H⁺+ 2e^- → H₂

At anode: C + 2OH^-→ CO + H₂O + 2e^-

The 1:1 mixture of CO and H₂ is called syngas. A current of 26.8 mA is applied for 1h. Assuming 100% efficiency what is the volume of syngas produced

• 22.4 mL

• 11.2 mL

• 44.8 mL

• 5.6 mL

A Li-ion battery used in an EV is charged within 10 minutes. The battery lasts for 6 hours under operation. What is the C rate at which the battery is charged and discharged

• 0.1C and 6C

• 6C and C/6

• C/6 and 6C

• 10C and C/6

A battery charges at a voltage of 4.5 V and discharges at a constant voltage of 3.9 V. The discharge capacity is 9 coulombs. If the battery has a coulombic efficiency of 90%, calculate the amount of energy lost as heat (in J).

• 5.4 J

• 5.7 J

• 40.5 J

• 9.9 J

Which of the following combinations of the reductant and oxidant would have the highest theoretical energy density for an energy storage device?

• F₂ and Li

• O₂ and Li

• F₂ and Be

• N₂ and Li

If a current of 20 A is continuously passed in the Zn-Br flow battery, what is the minimum flow rate (in mL/min) of 2 M ZnBr₂ solution that can support the current.

The reactions involved in a Zn-Br battery are

At the anode: Zn²⁺ + 2 e^-→ Zn

At the cathode: 2 Br^- → Br₂ + 2 e^-

• 3

• 6

• 9

• 12

Calculate the cell potential for a galvanic cell with a zinc electrode (Zn²⁺/Zn) at -0.76 V and an iron electrode (Fe³⁺/Fe²⁺) at +0.77 V. All potentials are given

• 0 V

• -0.765 V

• -1.53 V

• 1.53 V

A battery has a capacity of 2000 mAh. It is charged at C/4 rate. What is the current used for charging?

• 0.5 A

• 8 A

• 2 A

• 0.2 A

When TiS₂ was intercalated with Li⁺, the fraction of total octahedral voids occupied by cations in the system at SoC of 0.5 is

• 0.25

• 0.5

• 0.75

• 1

During the first charge-discharge cycle of a pristine Li-ion battery, the battery was charged at a current of 26.8 mA for 10 h. If the faradaic efficiency of the first cycle is 50%, and the area of the electrode is 100 cm². Calculate the thickness of the SEI when the average Li⁺ concentration in the SEI is 1 M assuming the irreversible capacity loss is entirely due to SEI formation and uniform SEI thickness with good homogeneity.

• 0.5 mm

• 50 μm

• 0.2 mm

• 20 μm

In Li₄Ti₅O₁₂ and Li₇Ti₅O₁₂, the fraction of octahedral sides that are occupied is respectively

• 0.5, 1

• 1, 1

• 0.5, 0.5

• 1, 0.5