The molecular mass of sodium = 23g
One mole of sodium consists of 23 g of sodium
One mole consists of 1 Avagadro(6.022 x 10^23 molecules) number of molecules
Therefore 23 g consists of 6.022 x 10^23 molecules of Sodium.
Hence 7.45 x 10^3 g of Sodium will consist of x no of molecules of sodium.
x no of molecules =
(7.45 x 10^3 g/23 g) x (6.022 x 10^23)
=1950.6 x 10^ 23 molecules (atoms).
To calculate for the structure
of an element, you need to have a solid analyzer such as an x ray
diffractometer to determine the elements’ structure. It is hard to determine it
without any help of instrument because of its size.
Answer:
pH 8.89
Explanation:
English Translation
If the MgCl₂ solution of 0.2 M has its pH raised by adding NH₄OH, the precipitate will begin to form at a pH of approximately.
Given the solubility product (Ksp) of Mg(OH)₂ = 1.2 x 10⁻¹¹
Assuming all of the salts involved all ionize completely
MgCl₂ ionizes to give Mg²⁺ and Cl⁻
MgCl₂ ⇌ Mg²⁺ + 2Cl⁻
1 mole of MgCl₂ gives 1 moles of Mg²⁺
Since the concentration of Mg²⁺ is the same as that of MgCl₂ = 0.2 M
Mg(OH)₂ is formed from 1 stoichiometric mole of Mg²⁺ and 2 stoichiometric moles of OH⁻
Ksp Mg(OH)₂ = [Mg²⁺][OH⁻]²
(1.2 x 10⁻¹¹) = 0.2 × [OH⁻]²
[OH⁻]² = (6×10⁻¹¹)
[OH⁻] = √(6×10⁻¹¹)
[OH⁻] = 0.000007746 M
p(OH) = - log [OH⁻] = - log (0.000007746)
pOH = 5.11
pH + pOH = 14
pH = 14 - pOH = 14 - 5.11 = 8.89
Hope this Helps!!!
Answer:
Ea= -175.45J
A= 3.5×10^14
k=3.64 ×10^14 s^2.
Explanation:
From
ln k= -(Ea/R) (1/T) + ln A
This is similar to the equation of a straight line:
y= mx + c
Where m= -(Ea/R)
c= ln A
y= ln k
a)
Therefore
21.10 3 104= -(Ea/8.314)
Ea=-( 21.10 3 104×8.314)
Ea= -175.45J
b) ln A= 33.5
A= e^33.5
A= 3.5×10^14
c)
k= Ae^-Ea/RT
k= 3.5×10^14 × e^ -(-175.45/8.314×531)
k = 3.64 ×10^14 s^2.
