Question

1.Calculati numarul de molecule din o zecime de mol de apa
2.Cat cantaresc 1000 de molecule de apa in grame?

Answer 1

ex.2
 1 mol= masa moleculara a substantei,
1mol apa ..............................18g  apa
1000 molecule.........................x
x= 1000*18/1 = 18000 g apa
ex.1
 1 mol de apa .........................6,23*10²³ molecule de apa

1/10 mol de apa .................... x

x= .6,23*10²³ ÷(1/10)= 62,3 *10²³ molecule de apa