In: Chemistry
Make a buffer with this solution: 0.1M NaCl, 0.5M Tris, 0.02% NaN3, pH 7.5, 500ml buffer
please provide detailed steps and explanations, thx
1.Weigh 30.285 gm of Tris.
Calculation: molarity of Tris .5,total volume 500 ml or .5 litre i.e .5*.5 =.25 moles of Tris needed. Molar mass of Tris 121.14g/mol.so .25*121.4=30.285 gm Tris should be weighed.
2.Weigh 2.922 gm of Nacl.
Calculation: molarity of NaCl .1,total volume .5 litre so .1*.5=.05 moles of Nacl needed.Molar mass of Nacl 58.44g/mol so .05*58.44 =29.22 gm of NaCl needed.
3.take .1 ml of NaN3 solution.
Calculation: .02 %=.0002, so .0002*500=.1 ml of NaN3 is needed.
4.Dissolve the required mass of Tris and NaCl and required volume of NaN3 in approximately 160 ml of deionised water.(1/3 rd of total volume).
5.Using a pH meter titrate titrrate the solution with HCl until the correct pH reached.
6.Add this mixture to a volumetric flask of 500 ml and fill up the remaining volume with deionised water.