how many grams of tris and tris Hcl are needed to make up 500ml of 1m tris buffer with a pH of 0.8?
Question makes no sense. pH of 0.8 or 8.0????
I assume you mean 1 M and not 1 m. M is molar; m is molal.
You need two equations.
equation 1 is
pH = pKa + log (base)/(acid)
equation 2 is
(base) + (acid) = 0.8 M
Use equation 1 and solve for (base)/(acid) then (base) = k(acid). Then plug that into equation 1 to find (base) and (acid). Convert molarities into grams per liter , then grams/500 mL.
Post your work if you get stuck.
pH is 8.0
Here's a reference that's useful for tris systems...(remove the space between the h t, copy and paste => search)
h ttp://www.sigmaaldrich.com/Graphics/Supelco/objects/4800/4709.pdf
To determine how many grams of tris and tris HCl are required to make up 500ml of a 1M tris buffer with a pH of 0.8, we need to follow several steps:
Step 1: Calculate the molar concentration of tris in the desired buffer. The molarity (M) is given as 1M, which means there is 1 mole of tris in every liter of solution. Since we want to prepare 500ml (0.5L) of buffer, the number of moles of tris needed can be calculated as follows:
Moles of tris = Molarity (M) × Volume (L)
Moles of tris = 1M × 0.5L = 0.5 moles
Step 2: Determine the molar mass of tris. Tris, or tris(hydroxymethyl)aminomethane, has a molecular formula of C4H11NO3. To find its molar mass, we sum up the atomic masses of its constituent elements, which can be obtained from the periodic table:
The atomic mass of carbon (C) = 12.01 g/mol
The atomic mass of hydrogen (H) = 1.01 g/mol
The atomic mass of nitrogen (N) = 14.01 g/mol
The atomic mass of oxygen (O) = 16.00 g/mol
Molar mass of tris = (4 × 12.01) + (11 × 1.01) + (1 × 14.01) + (3 × 16.00) = 121.14 g/mol
Step 3: Calculate the mass of tris needed using the calculated number of moles and the molar mass:
Mass of tris = Moles × Molar mass
Mass of tris = 0.5 moles × 121.14 g/mol = 60.57 grams
Step 4: Next, we need to calculate the molar concentration of tris HCl in the desired buffer. Similar to Step 1, we calculate the number of moles required:
Moles of tris HCl = Molarity (M) × Volume (L)
Moles of tris HCl = 1M × 0.5L = 0.5 moles
Step 5: The molar mass of tris HCl can be determined by summing up the atomic masses of its constituent elements. Tris HCl, or tris(hydroxymethyl)aminomethane hydrochloride, has a molecular formula of C4H12ClNO3. Using the atomic masses from the periodic table, we can calculate its molar mass:
Molar mass of tris HCl = (4 × 12.01) + (12 × 1.01) + 35.45 + (14.01) + (3 × 16.00) = 157.6 g/mol
Step 6: Calculate the mass of tris HCl using the calculated number of moles and the molar mass:
Mass of tris HCl = Moles of tris HCl × Molar mass
Mass of tris HCl = 0.5 moles × 157.6 g/mol = 78.8 grams
Therefore, to make 500ml of a 1M tris buffer with a pH of 0.8, you would need 60.57 grams of tris and 78.8 grams of tris HCl.