Answer:
Because the cohesive forces inside the droplets are stronger than the adhesive forces between both the drops and the wax, water does not penetrate waxed surfaces. Because the adhesive forces between the liquid and the glass are stronger than the cohesive forces inside the water, water wets glass and spreads out across it.
Explanation:
EDMENTUM
Balanced equation: 2Fe + 3H2O → Fe2O3 +3H2
Convert g to mols:
285/55.845 = 5.1034 mols
Mole ratio of Iron and Iron (III) Oxide: 2:1
5.1034/2 = 2.5517 mols
Answer:
Conociendo el volumen de solución, masa de soluto y su masa molar, es posible determinar: B) Concentración molar
La molaridad es la relación entre el número de moles de soluto y los litros de solución. Más:
M = No moles de solución de soluto / volumen (L)
Y a su vez los moles de soluto se encuentran por:
No moles de soluto = masa soluto / masa molar soluto
Answer:
0.42%
Explanation:
<em>∵ pH = - log[H⁺].</em>
2.72 = - log[H⁺]
∴ [H⁺] = 1.905 x 10⁻³.
<em>∵ [H⁺] = √Ka.C</em>
∴ [H⁺]² = Ka.C
∴ ka = [H⁺]²/C = (1.905 x 10⁻³)²/(0.45) = 8.068 x 10⁻⁶.
<em>∵ Ka = α²C.</em>
Where, α is the degree of dissociation.
<em>∴ α = √(Ka/C) </em>= √(8.065 x 10⁻⁶/0.45) = <em>4.234 x 10⁻³.</em>
<em>∴ percentage ionization of the acid = α x 100</em> = (4.233 x 10⁻³)(100) = <em>0.4233% ≅ 0.42%.</em>
