<u>Given:</u>
Calculated density values-
Aluminum = 2.7 g/cm3
Copper = 9.0 g/cm3
Iron = 7.9 g/cm3
Titanium = 4.8 g/cm3
Unknown sample mass = 9.5 g
Sample volume = 2.1 cm3
<u>To determine:</u>
The identity of the unknown sample
<u>Explanation:</u>
'Density' is a physical parameter which can be used to identify the nature of the unknown substance.
Density = Mass/Volume
For the unknown sample
Density = 9.5 g/2.1 cm3 = 4.52 g/cm3
This matches closely with the calculated density of titanium
Ans: The unknown substance is made of titanium
Answer:
pH = 6.999
The solution is acidic.
Explanation:
HBr is a strong acid, a very strong one.
In water, this acid is totally dissociated.
HBr + H₂O → H₃O⁺ + Br⁻
We can think pH, as - log 7.75×10⁻¹² but this is 11.1
acid pH can't never be higher than 7.
We apply the charge balance:
[H⁺] = [Br⁻] + [OH⁻]
All the protons come from the bromide and the OH⁻ that come from water.
We can also think [OH⁻] = Kw / [H⁺] so:
[H⁺] = [Br⁻] + Kw / [H⁺]
Now, our unknown is [H⁺]
[H⁺] = 7.75×10⁻¹² + 1×10⁻¹⁴ / [H⁺]
[H⁺] = (7.75×10⁻¹² [H⁺] + 1×10⁻¹⁴) / [H⁺]
This is quadratic equation: [H⁺]² - 7.75×10⁻¹² [H⁺] - 1×10⁻¹⁴
a = 1 ; b = - 7.75×10⁻¹² ; c = -1×10⁻¹⁴
(-b +- √(b² - 4ac) / (2a)
[H⁺] = 1.000038751×10⁻⁷
- log [H⁺] = pH → 6.999
A very strong acid as HBr, in this case, it is so diluted that its pH is almost neutral.
The molality is calculated using the following rule:
molality = number of moles of solute / kg of solvent
From the periodic table:
molar mass of lithium = 6.941 gm
molar mass of chlorine = 35.453 gm
molar mass of LiCl = 6.941 + 35.453 = 42.394 gm
number of moles found in 42 gm = mass / molar mass = 42 / 42.394 = 0.99
molality = 0.99 / 3.6 = 0.275 m
In order to deprotonate an acid, we must remove protons in order to achieve a more stable conjugate base. For this example, we can use the relationship between carboxylic acid and hydroxide.
Deprotonation is the removal of a proton from a specific type of acid in reaction to its coming into contact with a strong base. The compound formed from this reaction is known as the conjugate base of that acid. The opposite process is also possible and is when a proton is added to a special kind of base. This is a process referred to as protonation, which forms the conjugate acid of that base.
For the example we have chosen to give, the conjugate base is the carboxylate salt. This would be the compound formed by the deprotonated carboxylic acid. The base in question was strong enough to deprotonate the acid due to the greater stability offered as a conjugated base.
To learn more visit:
brainly.com/question/5613072?referrer=searchResults
Answer:
Well according to the Law of Evolution, depending on where the Finch lives and what it eats depends on it's beak size. For example, if a Finch lives on the coast and eats small fruits it will have a short and stubby beak to peck at the fruits, but if the Finch ate crabs it's beak would be long to swoop down and pluck up crabs.
Hope this helps!
