Write the sign convention of work done during expansion of gas.
Answer
In thermodynamics, the sign convention for work done during the expansion of a gas is negative. This means that when a gas expands, it does work on its surroundings, and the system (gas) loses energy. Hence, the work done by the system is considered negative.
Calculate effective atomic number of $(Co (NH_3)_6)^{3+}$ ion.
Answer
The oxidation state of Co is $+3$ , and ligands donate $12$ electrons.
$Z=27, X=3, Y=12$
$EAN$ of $Co ^{3+}= Z - X + Y$
$=27-3+(2 x \times 6)$
$=27-3+(12)$
$=36$