Answer:
Density is a value for mass, such as kg, divided by a value for volume, such as m3. Density is a physical property of a substance that represents the mass of that substance per unit volume. It is a property that can be used to describe a substance. We calculate as follows:
Volume = 60.0 g ( 1 mL / 0.70 g ) = 85.71 mL
Therefore, the correct answer is option B.
Explanation:
Answer: 9.98
Explanation:
1) The equation for the dissociation of pyridine is:
C₅H₅N₅(aq )+ H₂O(l) ⇄ C₅H₅NH⁺(aq) + OH⁻(aq)
2) Kb equation:
Kb = [C₅H₅NH⁺(aq)] [OH⁻(aq)] / [C₅H₅N₅(aq )]
Where:
[C₅H₅NH⁺(aq)] = [OH⁻(aq)] ← from the equilibrium reaction
[C₅H₅N₅(aq )] = 4.8 M ← from the statement
⇒ 1.9 × 10 ⁻⁹ = x² / 4.8 ⇒ x² = 9.12 × 10⁻⁹
⇒ x = 9.55 × 10⁻⁵ = [OH⁻(aq)]
3) pOH
pOH = - log [OH⁻(aq)] = 4.02
4) pOH + pH = 14
⇒ pH = 14 - 4.02 = 9.98
Calcula el Tanta por ciento en peso de soluto
