How many milliliters of 0.125 M Ba(OH)2(aq) must be used to produce 5.5 moles of water? Please balance the equation before solving the problem.

1 Answer
May 31, 2018

Answer:

You must use 22 L of the barium hydroxide solution.

Explanation:

There are three steps involved in this stoichiometry problem:

  1. Write the balanced chemical equation
  2. Use the molar ratio from the balanced equation to calculate the moles of #"Ba(OH)"_2#
  3. Calculate the volume of #"Ba(OH)"_2#

Step 1. Write the balanced chemical equation.

Let's assume you are using #"HCl"# as the acid.

#M_r:color(white)(mmmmmmmmmmmmmmmll) 18.02#
#color(white)(mmm)"Ba(OH)"_2 + "2HCl" →"BaCl"_2 + "2H"_2"O"#

Step 2. Calculate the moles of #"Ba(OH)"_2#

The molar ratio from the balanced equation is

#"Ba(OH)"_2:"H"_2"O"= 1:2#.

#"Moles of Ba(OH)"_2 = 5.5 color(red)(cancel(color(black)("mol H"_2"O"))) × ("1 mol Ba(OH)"_2)/(2 color(red)(cancel(color(black)("mol H"_2"O")))) = "2.75 mol Ba(OH)"_2#

Step 3. Calculate the volume of #"Ba(OH)"_2#

#"Volume of Ba(OH)"_2 = 2.75 color(red)(cancel(color(black)("mol Ba(OH)"_2))) × ("1 L Ba(OH)"_2)/(0.125color(red)(cancel(color(black)("mol Ba(OH)"_2)))) = "22 L Ba(OH)"_2#