The K_b for methylamine (CH₃NH₂) at 25 °C is given in Appendix D. (a) Write the chemical equation for the equilibrium that corresponds to K_b.

Video transcript

Welcome back everyone in this example. We have at 25 degrees Celsius triathlon mean has a KB of 5.6 times 10 to the negative fourth power. What is the chemical equation that corresponds to KB? So recall that KB is going to be our equilibrium constant for the ionization of a base in this case. Were given in the prompt triathlon, which we should recall is a weak base. And it makes sense as to why they give us our KB or this equilibrium constant. So we need to write out its reaction. So we're going to write out our formula so C two H five Sub three and then N this is Aquarius because it's going to dissolve in water. So we're going to react with water as our second reactant. And this is going to be an equilibrium reaction because we should recall that week basis or weak acids even always go through partial dissociation and equilibrium reactions. And so we're going to form our ion products as well as in this case hydro ni um due to water losing a proton. And so our first product is going to be our conjugate acid where we have C two H five three and then an H with a plus caddy on charge since our triathlon mean will have gained a proton. So conjugate acid here and then our second product as we stated, is from water which donated its product or sorry, donated a proton to our triathlon mean? And so therefore it loses a proton and we are left with hydroxide as our second product. Now will we check all of our atoms carbon, hydrogen, nitrogen and oxygen? We can see that everything is actually balanced. So this equation is balanced. We don't need to add any coefficients, so this entire balanced equation is going to be our final answer. To complete this example. I hope everything I reviewed was clear. If you have any questions, please leave them down below and I'll see everyone in the next practice video.