When we can get Pka for K2HPO4 =6.86 so we can determine the Ka :
when Pka = - ㏒ Ka
6.86 = -㏒ Ka
∴Ka = 1.38 x 10^-7
by using ICE table:
H2PO4- → H+ + HPO4
initial 0.4 m 0 0
change -X +X +X
Equ (0.4-X) X X
when Ka = [H+][HPO4] / [H2PO4-]
by substitution:
1.38 X 10^-7 = X^2 / (0.4-X) by solving for X
∴X = 2.3x 10^-4
∴[H+] = X = 2.3 x 10^-4
∴PH = -㏒[H+]
= -㏒ (2.3 x 10^-4)
∴PH = 3.6
Answer:
Two
Explanation:
The law of conservation of mass states that in an isolated system the mass present is neither destroyed nor created by chemical changes or physical changes.
This tells us that the mass of reactants must be equal to the product mass.
If 1 atom of Zn react with one atoms of sulfur, the product will be 1 molecule of zinc sulfide according to the equation below
Zn(s) + S(s) ⇒ ZnS(s)
therefore two atoms each f zinc and sulfur will product two molecules of Zn sulfide
Answer:
4.5 kg/L
Explanation:
Density is 4.5g/mL and it means that in 1 mL of volume, the mass contained is 4.5 g.
Let's make a rule of three
1L = 1000 mL
1 mL has a mass of 4.5 g
1000 mL would have 4500 g
Our new density would be 4500 g/L, but we may convert the g to kg
1 kg / 1000 g . 4500 g = 4.5 kg
In conclusion 4.5 g/mL = 4.5 kg/L
