Answer is: both reactions
are exothermic.
<span>
In exothermic reactions, heat is released and enthalpy of reaction is less than
zero (as it show second chemical reaction).
According to Le Chatelier's principle when the reaction
is exothermic heat is included as a product (as it show first
chemical reaction).</span>
It is a physical change when cream mixes with
coffee, it changes the color of the coffee. When you add more or less cream there
is a color change depending on the consistency of cream. The
properties are not changes and a no new compound is formed as in chemical
change with a reaction of two compounds, a new compound is formed with
different properties. So it is a physical change.
The answer is volume that is volume limits the precision of data obtained in an experiment .
As while pouring of the liquids, we control the volume, but it can have been off. And this could results in the wrong mole to mole ratio.Thus it limits the precision, So the answer is that volume limits the precision of data obtained in an experiment .
