Question

A. Care este masa de CO2 care contine aceeasi cantitate de oxigen ca si 4 moli de CaO?
b. Cate molecule de apa vor contine aceeasi cantitate de hidrogen ca si 3,4 de NH3?
c. Cati moli de H2SO4 contin aceeasi cantitate de oxigen ca si 1,89g de HNO3?
d. Calculati masa de SO3 care contine acelasi numar de molecule ca si cel continut in 640g de SO2?
e. Cate molecule de apa va contine solutia obtinuta prin dizolvarea a 25g de CuSO4× 5H2O in 75g de apa ?​.

Answer 1

Răspuns:

a.

MCaO= 40 + 16=56g/moli

n=m/M

m= 4moli x 56g/moli = 224g CaO

56 g CaO...............16gO

224g......................xgO

x= 224 x 16 / 56= 64g O

M CO2= 12 + 2x16= 44g/moli

44g  CO2.....................32g O

yg CO2..........................64gO

y= 44x64/ 32=  88 g CO2

b.

MNH3= 14 + 3= 17g/moli

17g NH3................3 g H

3,4g Nh3..............xgH

x= 3,4x 3 /17= 0,6 g H

MH2O= 2 + 16=18g/moli

18 g H2 O.................2g H

yg H2O.....................0,6g H

y= 18 x 0,6 /2= 5,4 gH2 O

n= 5,4g/ 18= 0,3 moli H2O

1mol H2O.........................6,022.x10²³ molecule H2O

0,3moli H2O.....................moleculez

z= 0,3 x 6,022x10²³/1= 1 , 8066 x 10²³molecule H2O

c.

M HNO3= 1 + 14 + 3.16= 63g/moli

63g HNO3.......................48g O

1,89g HNO3...................xg O

x= 1,89x48 /63= 1,44 g O

M H2SO4= 2 + 32 + 4.16=98g/moli

98g H2 SO4......................64g O

ygH2SO4.......................1,44gO

y= 98 x 1,44 / 64= 2,205 g H2SO4

n= 2,205g /98=0,0225moli H2SO4

d.

MSO2= 32 + 2x16=64g/moli

n= m /M

n= 640g / 64g/moli= 10 moli SO2

1mol SO2............................6,022x10²³molecule SO2

10 moli SO2.............................x molecule

x= 10x6,022x10²³/1= 60, 22x10²³ moleculeSO2

MSO3= 32 + 3.16= 80g/moli

1mol SO3..........................6,022x.10²³molecule SO3

zmoli SO3.......................60,22x10²³ molecule SO3

z= 60,22.10²³x1/6,022x10²³ = 10 moli SO3

m= nxM

m= 10moli x 80g/moli= 800g SO3

e.

M=64 + 32 + 4x16 + 5x18= 160 + 90=250g/mol

mapa = 90 g

250g CuSO4 .5H2O..................90g H2O

25gCuSO4 .5H2O.........................xg H2O

x= 25 x90 / 250= 9g H2O

mapa total= 75 + 9= 84g

n = 84g / 18g/moli=4,66moli H2O

1mol H2O...................-6,022x10 ²³ molecule H2O

4,66moli H2O........................x molecule

x= 4,66 x6,022x10²³/1= 28,06x10²³molecule H2O

Explicație: