When given a compound, adding up all of the of all of the individual atoms within one molecule of a compound will determine the molecular mass.

Answer is: atomic masses.

For example, calculate molecular mass of one mole of ethanol (C₂H₅OH). Molecule of ethanol has two carbon atoms, six hydrogen atoms and one oxygen atom:

M(C₂H₅OH) = 2Ar(C) + 6Ar(H) + Ar(O) · g/mol.

M(C₂H₅OH) = 2·12 + 6·1 + 16 · g/mol.

M(C₂H₅OH) = 46 g/mol; molar mass.

Atomic mass is approximately equivalent to the number of protons and neutrons in the atom.

answer: a tank of height h is filled with water and sits on the ground. water squirts from a hole at a height y above the ground and has a range r. for two y values, 0 and h, r is zero. determine the value of y for which the range will be a maximum.

explanation:

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"