6. What volume of 6M Ba(OH)2 will be needed to neutralize 400.0 ml of a 2.0 M HCl solution?

133 mL

Explanation:

M= mol solute/ L solution

mol solute= M *L solution

mol solute = (2.0 M * 0.4 L)

mol solute= 0.8 mol HCl= mol H

We need the same amount of  OH moles to neutralize the solution

L solution = mol solute/M

L solution= 0.8 mol Ba(OH)2/ 6M

L solution=0.133 L=133 mL

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation: