Choice c - eats away other materials
Answer:
A) secondary amide
Explanation:
When carboxylic acid reacts with a primary amine, a condensation reaction takes place with the elimination of a water molecule .
For example, ethanol reacts with methylamine which is a primary amine gives N-Methylacetamide and a water molecule as:

The bond formed which is
O
||
-- C ---NH ---
is known as secondary amide group as only one hydrogen is attached to nitrogen atom in the amide bond.
Reaction equation:
K₂CrO₄(aq) + PbCl₂(aq) → 2KCl(aq) + PbCrO₄(s)
Concentration = moles / Liter
moles(K₂CrO₄) = 3 x 0.025
= 0.075
By the equation, we see that the molar ratio of
K₂CrO₄ : PbCrO₄ is
1 : 1
moles(PbCrO₄) = 0.075
mass = moles x Mr
mass = 0.075 x (207 + 52 + 16 x 4)
mass = 24.2 grams