Answer:
ΔpH = 0.20
Explanation:
The buffer of HCO₃⁻ + CO₃²⁻ has a pka of 10.2
HCO₃⁻ ⇄ H⁺ + CO₃²⁻
There are 0.479moles of NaHCO₃ and 0.342moles of Na₂CO₃.
Using Henderson-Hasselbalch formula:
pH = pka + log [Base] / [Acid]
pH = 10.2 + log 0.342mol / 0.479mol
<em>pH = 10.05</em>
NaOH reacts with HCO₃⁻ producing CO₃²⁻, thus:
NaOH + HCO₃⁻ → CO₃²⁻ + H₂O + Na⁺
0.091 moles of NaOH produce the same moles of CO₃²⁻ and consume HCO₃⁻. Moles of these species are:
CO₃²⁻: 0.342mol + 0.091mol: 0.433mol
HCO₃⁻: 0.479mol - 0.091 mol: 0.388mol
Using Henderson-Hasselbalch formula:
pH = pka + log [Base] / [Acid]
pH = 10.2 + log 0.433mol / 0.388mol
pH = 10.25
That means change of pH, ΔpH is:
ΔpH = 10.25 - 10.05 = <em>0.20</em>
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I hope it helps!
<h3>
Answer:</h3>
H+ contains 1 proton, 0 neutrons, 0 electrons.
<h3>
Explanation:</h3>
- An atom is the smallest particle of an element that can take part in a chemical reaction.
- Atoms are made of sub-atomic particles neutrons and protons found in the nucleus and electrons found in the energy levels.
- A hydrogen atom contains 1 proton and 0 neutrons in the nucleus and 1 electron in the energy levels.
- A hydrogen atom loses an electron to form an ion with 1 proton, 0 neutron and 0 electron.
Answer:
B
Mark as the Brainliest please
most events like the rising and setting of the Sun were used a natural measurement of time until recently.
Solar time, which is based on the motion of the Sun, is not the only way of measuring time, however. One might keep track of the regular appearance of the full Moon. That event occurs once about every 29.5 solar days. The time between appearances of new moons, then, could be used to define a month.
One also can use the position of the stars for measuring time. The system is the same as that used for the Sun, since the Sun itself is a star. All other stars also rise and set on a regular basis.
Although any one of these systems is a satisfactory method for measuring some unit of time, such as a day or a month, the systems may conflict with each other. It is not possible, for example, to fit 365 solar days into 12 or 13 lunar months exactly. This problem creates the need for leap years
Read more: http://www.scienceclarified.com/Ti-Vi/Time.html#ixzz5e1E705sr
I abbreviated most of it but there is a ton more at this link if you still need more.
Answer:
B. 0.55 M
Explanation:
Step 1: Given data
- Moles of calcium chloride (solute): 1.5 mol
- Volume of solution: 2.75 M
Step 2: Calculate the molarity of the aqueous solution
The molarity is a way to express the concentration of a solution. It is equal to the quotient between the moles of solute and the liters of solution.
M = moles of solute / liters of solution
M = 1.5 mol / 2.75 L = 0.55 mol/L = 0.55 M
