$13.$The journey of finding the right solvent$$adventure in chemistry and economics.

a$.$ What surprises might pop up when you're hunting for the perfect solvent?

b$.$ How do cost considerations sneak into this scientific quest?

c$.$ What's a tale of a solvent choice gone right...or hilariously wrong?

$14.$The story behind each packing material's shape and surface area.

a$.$ Why isn't just any old shape good enough for packing material?

b$.$ What wizardry does surface area perform in the mass transfer spectacle?

c$.$ Ever heard of a packing shape that completely flopped? What happened?

$15.$ A study on fertilizer application techniques reveals that split applications of nitrogen fertilizer can reduce leaching and volatilization losses. What does split application involve?

$-$ A$)$ Applying the entire fertilizer amount at once, before planting

$-$ B$)$ Dividing the fertilizer application into multiple smaller doses throughout the growing season

$-$ C$)$ Mixing all types of fertilizers together before application

$-$ D$)$ Applying fertilizers at double the recommended rate

$16.$ The environmental impact of synthetic fertilizers includes nitrate leaching into groundwater. Which of the following practices can help reduce this impact?

$-$ A$)$ Increasing the frequency of irrigation

$-$ B$)$ Applying larger amounts of fertilizer less frequently

$-$ C$)$ Incorporating cover crops into crop rotations

$-$ D$)$ Removing buffer zones around water bodies