Answer:
pH = 8.34
Explanation:
The equilbriums of the amphoteric HCO₃⁻ (Ion of NaHCO₃) are:
H₂CO₃ ⇄ <em>HCO₃⁻</em> + H⁺ Ka1 <em>-Here, HCO₃⁻ is acting as a base-</em>
<em>HCO₃⁻</em>⇄ CO₃²⁻ + H⁺ Ka2 <em>-Here, is acting as an acid-</em>
Where Ka1 = 4.3x10⁻⁷ and Ka2 = 4.8x10⁻¹¹. As pKa = -log Ka:
pKa1 = 6.37; pKa2 = 10.32
As the pH of amphoteric salts is:
pH = (pKa1 + pKa2) / 2
<h2>pH = 8.34</h2>
Answer:
Fossils could be anything dug up from the ground, including crystals or human artifacts, but some of these objects aren't organic. Among the ones that were organic, they turned into a recognizable resemblance to living organisms.
Explanation:
there you go
The molality of the toluene is 1.46 mol/kg.
<h3>
What is molality?</h3>
The molality of a solution is its molal concentration. Molal concentration is denoted by m. It is the mol of solute dissolves in 1 Kg solvent.
The depression at freezing point is directly proportional to the molality of the solution. The equation we use for this type of problem is:
ΔT=iKm 
Where, ΔT is depression at freezing point, i is Van't hoff factor, m is molality and 
is the freezing point depression constant.
Toluene is a non-electrolyte and so the value of i for this is 1.
Depression at a freezing point is given as -13.
and the is given as 5.12. So, we could calculate the molality of the solution using the equation written above.
Let's plug in the values in the equation:
ΔT=iKm
-7.51 =1 x5. 12 xm
m = 
m = 1.46 m
It means the molality of the solution is 1.46 mol/kg.
Hence, the molality of the solution is 1.46 mol/kg.
Learn more about the molality of the solution here:
brainly.com/question/12123356
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Answer:
228.1 m
Explanation:
Area of the magnesium strip = 0.104m * 2.52 * 10^-3 = 2.62 * 10^-4 m^2
Density of Magnesium strip = 1.74g/cm3
Mass of magnesium strip = 0.104 g
But
density = mass/ area * thickness
density * area * thickness = mass
thickness = mass/density * area
thickness = 0.104 g/2.62 * 10^-4 * 1.74
thickness = 0.104 g/ 4.56 * 10^-4
thickness = 228.1 m
