$9.$ The overall gas phase mass transfer coefficient $($Kga$)$ is significant in:

$-$ A$)$ Determining the type of packing material.

$-$ B$)$ Calculating the rate of absorption$.$

$-$ C$)$ Estimating the minimum solvent flow rate.

$-$ D$)$ Designing the heat exchangers.

$10.$ When designing for the condition in the gas film, it's important to consider:

$-$ A$)$ The liquid phase mass transfer coefficient.

$-$ B$)$ The solvent capacity.

$-$ C$)$ The gas phase resistance.

$-$ D$)$ The type of packing material.

$11.$ The concept of minimum solvent flow rate is critical because it helps in:

$-$ A$)$ Maximizing the absorption efficiency.

$-$ B$)$ Reducing the operational costs.

$-$ C$)$ Simplifying the design calculations.

$-$ D$)$ Ensuring the structural integrity of the column.

$12.$ The absorption factor plays a crucial role in determining:

$-$ A$)$ The HETP.

$-$ B$)$ The NTU.

$-$ C$)$ The HTU.

$-$ D$)$ The rate of absorption$.$