Answer:
pH = 11.05
Explanation:
It is possible to answer this question using Henderson-Hasselbalch formula:
pH = pka + log₁₀ [A] / [HA⁺]
Where A in this case is weak base (dimethylamine) and conjugate acid (HA⁺) is dimethylamine hydrochloride.
As Ka= Kw / Kb = 1x10⁻¹⁴ / 7.4x10⁻⁴ = 1.35x10⁻¹¹ And pKa is -log Ka = <em>10.87 </em> pH of the solution is:
pH = 10.87 + log₁₀ [0.600] / [0.400]
<em>pH = 11.05</em>
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I hope it helps!
Answer:
<h2>0.15 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities.
From the question we have
We have the final answer as
<h3>0.15 moles</h3>
Hope this helps you
Answer:
The new temperature will be 2546 K or 2273 °C
Explanation:
Step 1: Data given
The initial temperature = 1000 °C =1273 K
The volume = 20L
The volume increases to 40 L
Step 2: Calculate the new temperature
V1/T1 = V2/T2
⇒with V1 = the initial volume = 20L
⇒with T1 = the initial temperature = 1273 K
⇒with V2 = the increased volume = 40L
⇒with T2 = the new temperature = TO BE DETERMINED
20L/ 1273 K = 40L / T2
T2 = 40L / (20L/1273K)
T2 = 2546 K
The new temperature will be 2546 K
This is 2546-273 = 2273 °C
Since the volume is doubled, the temperature is doubled as well
In order to find the mass of tin with the given volume of 5.5 L and density of 7.265, we will use the formula
Density = Mass / Volume
We will just multiply both sides of the equation by the volume and we will get:
Mass = Volume x Density
We can now solve the problem by substituting the given.
Mass = 5.5 L x 7.265 g/L
Mass = 39.96 g
Answer: there are 39.96 grams of tin
