Question

Am nevoi URGENT de rezolvarea exercitiilor de la 4 pana la 6. Dau 100 de puncte!!​

Answer 1

4.

a.

A = 2B

A-C = 4

C: K2e- L6e- => Z.C= 8 => O (oxigen)

=> A = 4+C = 4+8 = 12 Mg (magneziu)

=> B = A/2 = 12/2 = 6 C (carbon)

b.

O = +8

Mg = +12

C = +6

c.

O = K2e- L6e-

Mg = K2e- L8e- M2e-

C = K2e- L4e-

d.

O = 1 strat

Mg = 2 straturi

C = 1 strat

5.

a. K2e- L4e- => Z= 6

b. K2e- L8e- => Z= 10

c. K2e- L8e- M5e- => Z= 15

d. observam ca x=2 si y = 8

=> in M vom avea 8-2*2 = 4

=> K2e- L8e- M4e- => Z= 14

6.

stim ca:

1 mol ...... 22,4 L .......... miu ........ n6,022x10la23 particule

a.

M.Ca = 40 g

1 mol Ca ............... 40g .......... 6,022x10la23 atomi

                            500g .......... x = 7,53x10la24 atomi Ca

b.

M.Fe = 56 g

1 mol Fe ................... 56 g

10000 moli ............. m = 560000 g sau 560 kg

c.

K are Z=19 => 19e-

1 mol K ........................... 19x6,022x10la23 e-

2 moli ................................. n = 2,288x10la25 e-

d.

M.Cu = 64 g  ,  M.Zn = 65 g

1 mol Cu ......................64 g ............. 6,022x10la23 atomi Cu

                                  m g .............. 12,044x10la23 atomi Cu

                             = 128 g Cu

1 mol Zn .......................... 65 g

2 moli Zn ........................ n = 130 g Zn

=> m.Cu + m.Zn = 128+130 = 258 g amestec

%Cu = 128x100/258 = 49,61%

%Zn = 100-49,61 = 50,39%