Calculate in witch material - sodium or zinc sulphide is the highest percentage by mass of sulfur

sodium sulphide.

Explanation:

First, let us obtain the percentage of sulphur in both compounds. This is illustrated below:

For sodium sulphide(Na₂S):

Molar Mass of Na₂S = (23x2) + 32 = 46 + 32 = 78g/mol

Percentage of sulphur in Na₂S is given by:

32/78 x 100 = 41%

For zinc sulphide(ZnS):

Molar Mass of ZnS = 65.4 + 32 = 97.4g/mol

Percentage of sulphur in ZnS is given by:

32/97.4 x 100 = 33%

From the results obtained sulphur has the highest percentage by mass in sodium sulphide.

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.