If I have the following number of molecules of sulfur dioxide, how many grams is that?
4.57 x 1025 molecules

Mass = 4871.6 g

Explanation:

Given data:

Number of molecules of sulfur dioxide = 4.57 × 10²⁵ molecules

Mass in gram = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ molecules

4.57 × 10²⁵ molecules × 1 mol / 6.022 × 10²³ molecules

0.76× 10² mol

76 mol

Mass of sulfur dioxide:

Mass = number of moles × molar mass

Mass = 76 mol × 64.1 g/mol

Mass = 4871.6 g

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.