Question

Vreau raspunsurile la cerintele din poza. Dau coroana si 80p !
Multumesc ​

Answer 1

Răspuns:

1.

a)

numarul de electroni = numarul de protoni → 11 electroni (1 atom)

ne=0,48184·10²⁴ ·11= 5,30024 ·10²⁴

b)

n=0,48184·10²⁴/ 6,023·10²³=0,8moli

MNa=23g/mol

m=0,8·23=18,4g

c)

2moli......1 mol

2Na   +    H2SO4 → Na2SO4 + H2 ↑

0,8moli.......Xmoli

X=0,8·1/2=0,4moli H2SO4

MH2SO4=2·1 + 32 + 4 ·16=98g/mol

m=0,4 · 98=39,2g

2.

n=m/M=2,3/23=0,1moli

2moli..................2moli......1 mol

2Na + 2H2O → 2NaOH + H2↑

0,1moli...................X moli.....Y moli

X=0,1 ·2/2=0,1 moli

Y=0,1 ·1/2=0,05moli

MNaOH=23+16+1=40g/mol → mNaOH=4g

MH2=2·1=2g/mol → mH2=0,1g

md=40g

ms=md + ma apă= 2,3+100-0,1=102,2

C=md ·100/ms= 4 ·100/102,2=3,913%

Explicație: