Answer:
1045
Answer: 1045 J of energy was released on cooling the down the water from 20 °C to 10 °C.
Bromine attracts electrons more strongly. Cesium is In fact the least electro negative element.
Sodium is more likely to lose an electron because is is less electro negative. Strong electronegativity make the element want more electrons. Sodium has loose electrons with a lower electronegativity so it gives it up easier.
The chemical properties of an atom are determined by the number of the electrons while bonding is determined by the arrangement and the valency of the electrons.
<h3>What is an Atom?</h3>
The smallest component of ordinary stuff that makes up a chemical element is an atom. Atoms that are neutral or ionized make up every solid, liquid, gas, and form of plasma. Atoms are incredibly tiny, measuring typically 100 picometers across. Due to quantum effects, they are so small that it is impossible to predict their behavior with sufficient accuracy using classical physics, as would be the case, for example, if they were tennis balls.
Each atom is made up of a nucleus and one or more electrons that are linked to it. One or more protons and a significant number of neutrons make up the nucleus. Only the most prevalent type of hydrogen is neutron-free. The nucleus of an atom contains more than 99.94% of its mass.
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A buffer solution contains an equivalent amount of acid and base. The pH of the solution with an acid dissociation constant (pKa) value of 3.75 is 3.82.
<h3>What is pH?</h3>
The amount of hydrogen or the proton ion in the solution is expressed by the pH. It is given by the sum of pKa and the log of the concentration of acid and bases.
Given,
Concentration of salt [HCOO⁻] = 0.24 M
Concentration of acid [HCOOH] = 0.20 M
The acid dissociation constant (pKa) = 3.75
pH is calculated from the Hendersons equation as,
pH = pKa + log [salt] ÷ [acid]
pH = 3.75 + log [0.24] ÷ [0.20]
= 3.75 + log (1.2)
= 3.75 + 0.079
= 3.82
Therefore, 3.82 is the pH of the buffer.
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The pH of the solution in which one normal adult dose aspirin is dissolved is : 2.7
Given data :
mass of aspirin = 640 mg = 0.640 g
volume of water = 10 ounces = 0.295735 L
molar mass of aspirin = 180.16 g/mol
moles of aspirin = mass / molar mass = 0.00355 mol
<h3>Determine the pH of the solution </h3>
First step : <u>calculate the concentration of aspirin</u>
= moles of Aspirin / volume of water
= 0.00355 / 0.295735
= 0.012 M
Given that pKa of Aspirin = 3.5
pKa = -logKa
therefore ; Ka = 
= 
From the Ice table
= ![\frac{x + H^+}{[aspirin]}](https://tex.z-dn.net/?f=%5Cfrac%7Bx%20%2B%20H%5E%2B%7D%7B%5Baspirin%5D%7D)
= 
given that the value of Ka is small we will ignore -x
x² = 
x = 
Therefore
[ H⁺ ] =
given that
pH = - Log [ H⁺ ]
= - ( -3 + log 1.948 )
= 2.71 ≈ 2.7
Hence we can conclude that The pH of the solution in which one normal adult dose aspirin is dissolved is : 2.7
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