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.
c) nervous and endocrine system
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Answer:
Sulfur would gain electrons
Explanation:
Atoms want to have a complete out valence shell and because sulfur only needs 2 more electrons to complete the outer shell it would take 2 more.
Answer: 90 grams
0.5 molar of glucose means 0.5mole glucose for 1 liter of water. Since we want to made 1L of solution, then the amount of glucose needed is: 0.5mole/l x 1l= = 0.5mole
Glucose molecular weight is 180, then 0,5 mol of glucose is= 0.5mole x 180 grams/mole= 90 grams.
Answer:
True
Explanation:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
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