Write chemical equations for the reaction of potassium with the following substances, making sure that the numbers and kinds of atoms are the same on both sides of the equations. If no reaction occurs, write N.R.

(a) H2O

Video transcript

Hi, everyone. Welcome. Let's look at our next problem. It says write the chemical equations for the reaction of sodium with water. Write nr if it is predicted that no reaction will occur. And we have A B and C which are three different versions of our net ionic equations. And choice D is Nr Well, we can eliminate Nr right away. When we think about those group one, a metals like sodium, they react extremely violently with water. Uh There's a famous incident uh on the Charles River in Boston where Harvard students drop a block of sodium into the Charles River and cause quite an explosion to the entertainment of all the Spectators. And this is indeed a very exciting reaction. So choice D and no reaction cross that off. We see that all three of our answer. Choices A B and C do show one of the products being heat, this generates a lot of heat. So when we think about our one a metals, we have a generic formula for the reaction of them with water, they can react with protons in the water to produce this hydrogen gas since they give away their electrons. So easily. And that general reaction if M is our one, A metal is two M in a solid form plus 2 h2o in a liquid form becomes H two gas plus two M plus aqueous plus 2 0 minus aqueous plus heat. So we see that corresponds to choice C where we've replaced the M with N A sodium and we have that two N A solid plus two water liquid becomes H two gas plus two N A plus aqueous plus 2 0 minus aqueous plus heat. So choice C is going to be our answer. We can briefly take a look at A and B, neither of them has hydrogens balanced in this equation. In choice A, we see the two hydrogens in our water on the left side, but there are two hydrogens in the H two gas and another hydrogen in the oh minus. So the hydrogens don't balance. So we can cross that choice. A choice B as well. The hydrogens do not balance. We have two hydrogen in our water, two hydrogens in the hydrogen gas. And then this shows two hydrogens in the oh minus. So choice B also not a balanced equation. So that's why our answer is choice. C see you in the next video.