Question

Determinati numarul total de atomi dintr-un amestec care cntine 4,8 g magneziu si 0,4moli de calciu.

Answer 1

se afla nr. moli Mg

n=m:M

n=4,8 g: 24 g/moli=0,2 moli Mg

1mol Mg ----------6,023.10²³ atomi Mg

2moli----------------x

x=2. 6,023 .10²³atomi Mg=12,046.10²³atomi Mg

se afla nr. de atomi din 0,4 moli Ca

1mol Ca---------6,023.10²³atomi Ca

0,4 moli Ca----------y

y=0,4 . 6,023 .10²³ atomi Ca=2,4092 .10²³atomi Ca

12,046 .10²³+ 2,4092 .10²³=14,4552 .10²³ atomi in total