Hurry 60 how does the law of conservation of mass apply to this reaction:

c2h4+o2=2h2o+2co2?

1. the law of conservation of mass has already been applied. there is an equal number of each element on both sides of the equation.

2. the equation needs to be balanced. there are fewer oxygen atoms in the equation than hydrogen or carbon.

3. only the oxygen needs to be balanced. there are equal numbers of hydrogen and carbon.

4. each element needs to be balanced

2

Explanation: The equation needs to be balanced in order for the law of conservation of mass to be applied.

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.