It's b. calcium
because the outer electron structure in all of that element is similar, they have the same chemical and physical properties.<span />
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:
a substance made by mixing other substances together.
Explanation:
A mixture is a substance made by mixing two or more substances together.
Answer: 1:4.69
Explanation:
The ratio can be expressed as:
Ua/Ub= √(Mb/Ma)
Where Ua/Ub is the ratio of velocity of hydrogen to carbon dioxide and Ma is the molecular mass of hydrogen gas= 2
Mb is the molecular mass of CO2 = 44
Therefore
Ua/Ub= √(44/2)
Ua/Ub = 4.69
Therefore the ratio of velocity of hydrogen gas to carbon dioxide = 1:4.69
which implies hydogen is about 4.69 times faster than carbon dioxide.
