Răspuns:
M,HCl= (1gH +35,5gCl)/mol= 36,5g/mol....masa molara
36,5g HCl........contine ....1gH
71g.........................................x... x=m=71/36,5=1,95gH
M,ZnO=( 65gZn + 16gO)/mol=81g/mol...masa molara
81g ZnO......contine ..........65gZn
20g................................... ..........x x=m= 20x65/81=16gZn
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Explicație: