Zn + 2HCl → ZnCl2 + H2
What is the half reaction for the reduction of hydrogen in the reaction?

2H^+ +2e -> h2(g)

Explanation:

Since hydrogen is reduced, look for a decrease in oxidation number and the gain of electrons.

1.667L of a 0.30M BaCl₂ solution

Explanation:

Of a 0.30M barium chloride, contains 500.0mmol of barium chloride.

Molarity is an unit of concentration used in chemistry defined as the moles of solute present in 1 liter of solution.

In a 0.30M BaCl₂ solution there are 0.30 moles of BaCl₂ in 1 liter of solution.

Now, in your solution you have 500mmol of BaCl₂ = 0.500 moles of BaCl₂ (1000 mmol = 1 mol). Thus, 0.500 moles of BaCl₂ are present in:

0.500 moles * (1L / 0.30 moles) =