GCSE chemistry homework help

1) What is the concentration of a solution made by adding 65ml of water to 95 ml of 22mM CaCL2 ?

2) DNA loading buffer is made up of the following constituents dissolved in sterile deionised water:

• 2.5 % v/v Glycerol, 0.4% w/v Bromophenol blue (MW 670.02)
• 6.2 % w/v SDS (MW 288.38)

To make 200ml of buffer work out the amounts of Glycerol ml, Bromophenol Blue g and the SDS g.

3) What is the concentration of sodium chloride (NaCl MW 58.5) in a 400mM solution. Answer in g/L

4) To make 10L of Tris buffer saline which contains 50mM Tris and 150mM NaCl

How much Tris and NaCl are required to make up 10L of TBS (tris MW:121.14, NaCl, MW 58.5)