How many molecules of water are there in 0.80 mol of water?

4.816 x 10^23, because the number of atoms in one mole of any compound, mixture, or pure substance is 6.02 x 10^23, and multiplying that by 0.8 moles you get that there are 4.816 x 10^23 atoms in 0.8 moles of water.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

може ли да зареждате повече информация, моля