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
Answer:
The answer to your question is: density = 0.993 g/ml
Explanation:
Data
mass beaker empty = 29.3 g
volume of liquid = 15 ml
mass beaker + liquid = 44.2 g
Formula
density = mass / volume
Process
mass of liquid = 44.2 - 29.3
= 14.9 g
density = 14.9 / 15
= 0.993 g/ml
The kind of radioactive element is useful for dating an object is one with a half-life close to the age of the object.
<h3>What are radioactive elements?</h3>
Radioactive elements are elements that involved in radioactivity and this comprises of atoms or particles in their nuclei whose atomic nuclei are not stable and they emit radiations to maintain stability.
Therefore, The kind of radioactive element is useful for dating an object is one with a half-life close to the age of the object.
Learn more about radioactive elements below.
brainly.com/question/10257016
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Answer:
Oxide of M is 
and sulfate of 
Explanation:
0.303 L of molecular hydrogen gas measured at 17°C and 741 mmHg.
Let moles of hydrogen gas be n.
Temperature of the gas ,T= 17°C =290 K
Pressure of the gas ,P= 741 mmHg= 0.9633 atm
Volume occupied by gas , V = 0.303 L
Using an ideal gas equation:
Moles of hydrogen gas produced = 0.01225 mol
Moles of metal =
So, 8.3333 mol of metal M gives 0.01225 mol of hydrogen gas.
x = 2.9 ≈ 3
Formulas for the oxide and sulfate of M will be:
Oxide of M is and sulfate of .
