Using avogadro's number (6.02*10^23): calculate the number of molecules in 3.00 moles h2s . express your answer numerically in molecules.. calculate the number of moles of cl atoms in 1.81×10^24 formula units of magnesium chloride, mgcl2 .

Explanation:

For this question we have to take into account that the ratio between moles and molecules:

Then, using this ratio we can do the conversion:

For the next question we have to keep in mind that the formula units are a synonym for molecules and we have to use two ratios:

Using these two ratios:

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-