Complete and balance the equation for each of the following reactions.

b. Ca(s) + H₂O(l) →

Video transcript

All right. Hi, everyone. So this question is asking us to provide the complete balanced reaction equation for the following in which solid barium metal combines with liquid water. Here, we've got four different inter choices, proposing four different reaction products and different stoichiometry ratios. So the first thing I want to point out here is that the metal in question happens to be barium which is found in group two a of the periodic table. And the reason why I wanted to bring this up is because recall the fact that medals in groups one A and two A tend to react very violently with water, right? And when they do so, they form a few different products, primarily hydrogen gas or H two as well as the corresponding metal ion and the hydroxide ion. So to illustrate our products here, I'm actually going to go ahead and rewrite my reaction on the bottom. So on the right side of the arrow, I'm going to write hydrogen gas as one of my products as well as the corresponding metal ion. Now, because barium is in group two A of the periodic table, the ion that's going to form is going to be B A two plus aqueous. And then in addition to this, I'm also going to form hydroxide also aqueous. However, recall that it's not simply enough to write down the products of the reaction, you must make sure that they're balanced, right? You must make sure that there is the same quantity of every type of atom present on either side of your equation. So when I consider barium, barium happens to be balanced, but hydrogen actually is not right because if I scroll down here notice how I have two atoms of hydrogen on the left side and three hydrogen atoms on the right side. So I can balance this by adding some stoichiometry coefficients starting off with adding a stoichiometry coefficient of two in front of water on the left side. Now because this is also going to change the amount of oxygen atoms I have on the left side of the equation, I'm going to add another coefficient of two in front of hydroxide on the right side of the ar. So that when all is said and done, I end up with my balanced reaction. So one equivalent of solid barrier metal combines with two equivalents of liquid water to produce one equivalent of hydrogen gas, one equivalent of barium ion and two equivalents of hydroxide ion. So the answer choice here that matches the balance reaction that I just obtained is going to be option d in the multiple choice. So that is the correct answer. And with that being said, thank you so very much for watching and I hope you found this helpful.