Sr N(e⁻)=38
Sr²⁺ N(e⁻)=38-2=36
36e⁻
The number of molecules= 3.55 x 10²⁴
<h3>Further explanation</h3>
Given
5.9 moles of NaCl
Required
The number of molecules
Solution
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
So for 5.9 moles :
= 5.9 x 6.02 x 10²³
= 3.55 x 10²⁴
Given data:
Hydrogen (H) = 3.730 % by mass
Carbon (C) = 44.44%
Nitrogen (N) = 51.83 %
This means that if the sample weighs 100 g then:
Mass of H = 3.730 g
Mass of C = 44.44 g
Mass of N = 51.83 g
Now, calculate the # moles of each element:
# moles of H = 3.730 g/ 1 g.mole-1 = 3.730 moles
# moles of C = 44.44/12 = 3.703 moles
# moles of N = 51.83/14 = 3.702 moles
Divide by the lowest # moles:
H = 3.730/3.702 = 1
C = 3.703/3.702 = 1
N = 3.702/3.702 = 1
Empirical Formula = HCN
5 degrees because five - 5=0 which is where you need to get to
1) using your senses!
2)infering
3)predicting
4)making models
hope this helped XD
