Potassium cyanide is a toxic substance, and the median lethal dose depends on the mass of the person or animal that ingests it. The median lethal dose of KCN for a person weighing 215 lb (97.5 kg ) is 8.84×10−3 mol . What volume of a 0.0250 M KCN solution contains 8.84×10−3 mol of KCN?

Express the volume to three significant figures and include the appropriate units.

0.354L

Explanation:

Given parameters:

Molarity of KCN  = 0.025M

Number of moles  = 8.84 x 10⁻³mol

Unknown:

Volume of KCN  = ?

Solution:

The molarity of a substance is expressed as;

       Molarity  =  

 Volume of KCN   =

Now insert the parameters and solve;

  Volume of KCN  =   = 0.354L

petroleum? coal maybe?

  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-