One of the best buffer choice for pH = 8.0 is Tris with Ka value of 6.3 x 10^-9.
To support this answer, we first calculate for the pKa value as the negative logarithm of the Ka value:
pKa = -log Ka
For Tris, which is an abbreviation for 2-Amino-2-hydroxymethyl-propane-1,3 -diol and has a Ka value of 6.3 x 10^-9, the pKa is
pKa = -log Ka
= -log (6.3x10^-9)
= 8.2
We know that buffers work best when pH is equal to pKa:
pKa = 8.2 = pH
Therefore Tris would be a best buffer at pH = 8.0.
Answer: 0.0250
Explanation: 10 X 0.0750 = .75
.75 / 30 = 0.0250 M
Option D
A precipitate is the term for a solid that forms when two solutions are mixed
<u>Explanation:</u>
A solid set from a couple of solutions is termed a precipitate. A precipitate is an unsolved solid that makes when a pair of solutions are fused and react chemically. Unsolvable means that the solid will not melt. When the effect transpires in a liquid solution, the solid developed is denominated the 'precipitate'.
The substance that generates the solid to make is termed the 'precipitant'. Seldom the development of a precipitate symbolizes the existence of a chemical reaction. Precipitation may additionally transpire immediately from a supersaturated solution.
<h3>
Answer:</h3>
15 moles
<h3>
Explanation:</h3>
The decomposition of boron carbonate is given by the equation;
B₂(CO₃)₃(s) → B₂O₃(s) + 3CO₂(g)
Moles of boron carbonate decomposed is 5.0 mol
To find the moles of CO₂ produced we are going to use the mole ratio.
Mole ratio of B₂(CO₃)₃ to CO₂ is 1 : 3
Therefore;
Moles of CO₂ = Moles of B₂(CO₃)₃ × 3
= 15 mol
Therefore, 15 moles of CO₂ will be produced
<u>Answer:</u> The theoretical yield of the lithium chlorate is 1054.67 grams
<u>Explanation:</u>
To calculate the mass for given number of moles, we use the equation:
Actual moles of lithium chlorate = 9.45 moles
Molar mass of lithium chlorate = 90.4 g/mol
Putting values in above equation, we get:
To calculate the theoretical yield of lithium chlorate, we use the equation:
Actual yield of lithium chlorate = 854.28 g
Percentage yield of lithium chlorate = 81.0 %
Putting values in above equation, we get:
Hence, the theoretical yield of the lithium chlorate is 1054.67 grams
