I’m assuming the cordial is cocoa, two cups equals a pint. So he should add 1 pint or 2cups of water. Whichever measurement you need.
Acids are chemicals with a pH less than 7 that can donate a proton or H+ ion in a reaction. Bases have a pH greater than 7 and can accept a proton or produce an OH- ion in a reaction. If you mix equal amounts of a strong acid and a strong base, the two chemicals essentially cancel each other out and produce a salt and water. Mixing equal amounts of a strong acid with a strong base also produces a neutral pH (pH = 7) solution. This is called a neauturization and looks like
HA + BOH → BA + H2O + heat
A. gravity (of any planet/star/celestial body around )
D. Inertia
E. Centripetal force