Answer:
Explanation:
Here, we want to calculate the number of formula units in the given molecule
We start by getting the number of moles
To get the number of moles, we have to divide the mass given by the molar mass
The molar mass is the mass per mole
The molar mass of calcium bromide is 200 g/mol
Thus, we have the number of moles as follows:
The number of formula units in a mole is:
The number of formula units in 0.2075 mole will be:
Phosphorus is in group 15 meaning it have 5 valence electrons. This means that it needs 3 more electrons to create a full outer shell. As these three electrons are negatively charged it means that P is a 3- ion (it’s an anion [negatively charged ion])
question 1
moles = mass/molar mass of Al(OH)3
convert Kg to g
that is 1.09 x 1000=1090g
moles is therefore=1090g/78(molar mass of Al(OH)3)= 13.974 moles
question 2
moles=2.55g/327.2(molar mass of Pb(CO3)2= 7.79 x 10^-3 moles
from avogadro constant
1moles=6.02 x10^23 formula units
what about 7.79 x 10 ^-3
={(7.79 x 10^-3)moles x ( 6.02 x10^23)} /1 mole=4.69 x10^21 formula units
