Question

400g de naoh são adicionados a 504g de hno3. calcule? heeelllpppp :)

Answer 1

as massas molares de cada substancia sao :

MM(HNO3)
= 1 + 14 +(3x16)
= 15 + (3x16)
= 15 + 48
= 63g/mol

MM(NaOH(
= 23 + 16 + 1
= 39 + 1
= 40g/mol

MM(NaOH3)
= 23 + 14 + (3X16)
= 37 + 48
= 85g/mol

MM(H2O)
= 2,1 + 16
= 18,10 g/mol

A reacao juntos com as propircies massicas fica :

NaOH + HNO3 ---> NaNO3 + H2O

40g + 63g ---> 85g + 18g

fazeremos uma regra de trws simples :

40g NaOH===========63g HNO3
400g NaOH==========X HNO3

X = 400 . 63
......._______
..............40

X = 25.200
......______
............40

X = 630g



63g HNO3============85g NaNO3
504g HNO3=========== X g NaNO3

X = 504 x 85
......._______
..............63

X = 42.840
.......______
............63

X = 680g NaNO3


63g HNO3=============40g NaOH
504g HNO3============X g NaOH

X = 504 . 40
...... _______
..............63

X = 20.160
......______
........ 63

X = 320g NaOH

vamis sunstraie as massas em excessi sera :

m(NaOH exc) = 400 - 320
m(NaOH exc) = 80g NaOH