Question

cuantos gramos de zn reaccionan con 43g de hidroxido sodico para producir hidrogeno gaseoso

Answer 1

Zn° + 2 NaOH-----> Na2ZnO2 + H2 (g) 

PM NaOH= 40 (23+16+1) 

40 grs----- 1 mol NaOH 
43 grs------ x= 1.075 moles NaOH 

2 moles de NaOH---- 1 mol de Zn 
1.075 moles NaOH---- x= 0.5375 mol de Zn 

PM Zn= 65.40 

1 mol Zn---- 65.40 gr 
0.5375 mol Zn---- X=35.1525 gr 

Answer 2

Zn + 2NaOH → Na2ZnO2 + H2

Mm NaOH = 40 g/mol
             Zn = 65.39 g/mol

g Zn= 43 g NaOH x 1 mol NaOH x 1 mol Zn     x  65.39 g Zn
                                 ````````````````    ````````````        ````````````````
                                   40 g NaOH   2 mol NaOH    1mol Zn

g = 35,147 de zinc