“na2so3” represents sodium sulfite. what does the 4 mean in the formula 4na2so3?

The mass of substance which consists the equal number of particles as 12 grams of Carbon-12 is said to be mole.

For example:

The balanced chemical equation for production of water from hydrogen and oxygen is:

That means 2 moles of reacts with 1 mole of to give 2 moles of  .

The given formula is .

Hence, 4 represents the number of moles in formula that is 4 moles of .

The number of atoms of sodium, in is:

The number of atoms of sulfur, in is:

The number of atoms of oxygen in, in is:

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.