A biologist has two brine solutions, one containing 4% salt and another containing 16% salt. How many milliliters of each solution should she mix to obtain 1 L of a solution that contains 11.2% salt?

400 mL of 4% salt solution and 600 mL of 16% salt solution need to be mixed

Explanation:

Let's assume concentration of brine salt solutions are in %(w/v) unit.

Final mixture has a concentration of 11.2% salt and volume of 1 L or 1000 mL

Hence, amount of salt in final mixture =

Suppose x mL of 4% salt solution and (1000-x) mL of 16% salt solution need to be mixed to get final mixture

So, amount of salt in x mL of 4% salt solution =

      amount of salt in x mL of 16% salt solution =

Hence,

or,

So, 400 mL of 4% salt solution and 600 mL of 16% salt solution need to be mixed

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-