NH4+ and NH3 are an acid-conjugate base pair, since NH4+ is an acid, while NH3 is its conjugate base (since it is without the H+).
H2O and H3O+ can also be considered an acid-conjugate base pair, since H3O+ is an acid, while H2O would be its conjugate base. (But if only 1 answer is to be selected, it should be the NH4+ and NH3)
NH4+ and H3O+ are both acids, and both H2O and NH3 can be considered bases.
I believe the correct answer would be that it feels slippery. Being slippery or soapy is one characteristic of a base. This due to the fact that it dissolves the oils and fatty acids from the skin. Other characteristics would be that it turns litmus paper blue and has a bitter taste.
Answer: products; reactants
Explanation: as the endothermic reactions are tye one which absorbs energy
Answer : 7.87 X

.
Explanation : To find the fraction of schottky defects in the given lattice of CsCl,
we use the formula,

on solving with the given values ,

and T as 645 + 273 K and rest are the constants.

we get the answer as 7.87 X

.