Question

Transfer buffer is made up as follows: 6.06 g Tris base 28.8 g Glycine Make up volume to 1800 ml with distilled water. Add 200 ml Methanol. Question 1 Answer saved Marked out of 1.00 Flag question What is the concentration of Methanol in the Transfer Buffer? Select one: a. 20 mM b. 200 mM c. 20% d. 10% e. 200 ml/L

Answer 1

Question 1)

As the total volume of buffer solution is

2000 mL in which 200 mL methanol is present. We can find out the concentration of methanol in percentage by considering.

2000 mL = 100 %

As only 200 mL of Methanol added

200 mL = (200 x 100) / 2000

= 10 %

Therefore concentration of methanol is 10 %.

​​​​​Question 2)

As 28.8 g of glycine is present in 2000 mL = 2L. We can consider

2L = 28.8 g of glycine

For 1 L = 28.8 / 2 = 14.4 g/ Lit

Therefore answer is, 14.4 g/ L

Question 3)

The molecular weight of Tris is 121.14 g/ mol. The number of moles of Tris in 2000 mL can calculated by using following formula.

Number of moles of Tris = weight of Tris in g / Molecular Weight of Tris in g/ mol

Number of moles of Tris = 6.06 g / 121.14 g/mol

= 0.734 mol

There are 0.734 moles of Tris present in 2000 mL. Number of moles if trying s present in 1000 mL will be,

2000 mL = 0.734 moles

1000 mL = (1000 x 0.734) / 2000 = 0.367 moles = 0.367 M

Therefore, the molar concentration will be 0.367 M.