Thermochemical equations can be written two ways: with the heat written on the reactant side (endothermic) or product side (exothermic); or written to the right of the
reaction as AH with the appropriate sign to indicate positive (endothermic) or negative
(exothermic) reactions. For the following thermochemical reactions, rewrite the equation the
second way

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.