Question

Test/tema la chimie pe nota am timp 5 zile sa trimite rezolvarea va rog.​

Answer 1

Răspuns:

1.

md=240g

C=10%

ms=?

C=md×100/ms

ms=md×100/C=240×100/10 = 2400gNaOH

2.

1mol......1mol.......1mol

S     +     O₂  →  SO₂

3mol.........x.............y

x=3×1/1=3moli O₂

y=3×1/1=3moliSO₂

MSO₂=32+2×16=64g/mol

n=m/M

mSO₂=3×64=192g SO₂

3.

a) NaOH

MNaOH = 40 g/mol

40 g NaOH................23 g Na..................16 g O.................1 g H

100g NaOH......................x%Na....................y%O...................z%H

x = 23×100/40 = 57,5% Na

y = 16×100/40 = 40% O

z = 1×100/40 = 2,5% H

b) NaCl

MNaCl = 58,5 g/mol

58,5 g NaCl.....................23 g Na .....................35,5 g Cl

100g NaCl........................x% Na..............................y% Cl  

x = 100×23/58,5 = 39,3% Na

y = 100×35,5/58,5 = 60,7% Cl

c) Na2S

MNa₂S = 78 g/mol

78 g Na2S.........................46 g Na.......................32 g S

100g Na₂S...........................x% Na.........................y% S  

x = 46×100/78 = 59% Na

y = 32×100/78 = 41% S

4.

a)

H₂O

raport atomic H : O = 2 : 1

b)

ZnCO₃

raport atomic Zn : C : O = 1 : 1 : 3

c)

Cu(OH)₂

raport atomic Cu : O : H = 1 : 2 : 2

5.

a) MgCO₃

raport de masa Mg:C:O=24:12:48=2:1:4

b) CaCO₃  

raport de masa Ca:C:O=40:12:48=10:3:12

c) Na₂O

raport de masa Na:O=46:16=23:8

6.

a)

2HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + 2H₂O

b)

2KOH + CaO → Ca(OH)₂ + K₂O

c)

3Ca + 2H₃PO₄ → Ca₃(PO₄)₂ + 3H₂↑

d)

3H₂SO₄ + 2Fe(OH)₃ → Fe₂(SO₄)₃ + 6H₂O

Explicație: