Calculate the number of moles and the mass of the solute in each of the following solutions: (a) 2.00 l of 18.5 m h2so4, concentrated sulphuric acid
(b)100.0 ml of 3.8 x 10-5 mnacn, the minimum lethal concentration of sodium cyanide in blood serum
(c)5.50 l of 13.3 m h2co, the formaldehyde used to "fix" tissue samples.
(d)325 ml of 1.8 x 10-6 m feso4, the minimum concentration of iron sulphate detectable by taste in drinking water.

Explanation:

c = Concentration of the solution

n = Moles of compound in solution

V = Volume of the solution

a) 2.00 L of 18.5 M of concentrated sulfuric acid.

n= ? c = 18.5 M, V = 2.00 L

n = 37 moles of sulfuric acid

b) 100.0 mL of of  sodium cyanide

n= ? ,c = , V = 100.0 mL = 0.1 L

n = of sodium cyanide

c) 5.50 L of 13.3 M of concentrated formaldehyde.

n= ? c = 13.3 M, V = 5.50 L

n = 73.15 moles of formaldehyde.

d)325 mL of of  iron sulphate

n= ? ,c = , V = 325 mL = 0.325 L

n = of iron sulfate.

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l