Assignment on Chemistry - Number of atoms

Running head: CHEMISTRY
CHEMISTRY ASSIGNMENT
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Author Note

CHEMISTRY1
1.
a. Al2(SO4)3= (27 x 2)+ (32+64) x 3= 342 g/mole
b. mass= n x M (molecular mass)
or, 22.5= n x 65
or number of moles (n) of Zn= (22.5/65)= 0.34
c. Using the formula,
mass= n x M
m (mass)= 12.5 x 35= 437.5 grams (Cl2)
d. Number of atoms in CH4= 1+4= 5
Molar mass= 16
Number of moles in 0.25 g sample= (0.25/16)= 0.01
Therefore, the number of atoms= 6.023 x 1023 x 0.01 x 5= 0.3 x 1023 atoms.
e. Mass of one molecule of N2O5= 108/ (6.022 x 1023)
Mass of four molecule = 4 x 1.8 x 10-22= 7.17 x 10-22 g
f. Molar mass of C2H4= 26
or, 1 mole= 26 grams
Therefore, 9.6 grams will have= 9.6/26= 0.17 mole
g. According to Avogadros’s constant,
1 mol of an atom= 6.022 x 1023 atoms
Thus, for 22 atoms, we have= (22/6.022 x 1023)= 3.65 x 10-23 mol