Write equations for the following acid–base reactions. Label t...

Question

Write equations for the following acid–base reactions. Label the conjugate acids and bases, and show any inductive stabilization. Predict whether the equilibrium favors the reactants or products. Try to do this without using a table of pK_a values, but if you need a hint, you can consult Appendix 4.
g. NaOCH₂CH₃ + Cl₂CHCH₂OH
h. H₂Se + NaNH₂
i. CH₃CHFCOOH + FCH₂CH₂COO^–

g. NaOCH₂CH₃ + Cl₂CHCH₂OH

h. H₂Se + NaNH₂

i. CH₃CHFCOOH + FCH₂CH₂COO^–

Accepted Answer

Welcome back everyone to another video, complete the acid base reactions given below label each reactions conjugate acid and base and predict whether the equilibria favor reactants or products. We're given two examples. Let's begin with the first one and then the first one we're given hydro tolu acid, it reacts with sodium amide. We know that sodium is a metal. So it is an iron spectator and therefore, we can write our reaction. Let's emit sodium carry on from our equation for now. And this leaves us with amide with a negative charge. We can essentially tell that hydro thur acid is our acid because it contains protons bonded to Turri and amide is our base because it has a negative charge, it can act as a proton acceptor. So based on the bronze of Laurie theory, we know that assets are proton donors and bases are proton acceptors. Therefore, aide captures one of the hydrogens to become ammonia and H three. And we are also producing HTE with a negative charge because hydro toric acid essentially loses one hydrogen. Now, if we simply introduce the iron spectator, let's re remove the negative charges and add sodium instead. Now assets produce conjugate bases. Meaning nahte is our conjugate base and ammonia is produced from a base, meaning it's a conjugate acid. Well, then we have our assignment now to consider whether the equilibrium favors, react on to our products. We have to take for example, two of our acids. Let's consider hydro toric acid and ammonia. Let's recall that whenever we go down in the periodic table across our periods, the atomic radius increases and the radius of tellurium is greater than the radius of nitrogen, the greater the radius, the weaker the attraction force between hydrogen and the central atom. And therefore, those hydros would be more acidic, which tells us that hydro toric acid is a stronger acid than ammonia. In fact, ammonia is basic, right? Let's also recall that equilibrium favors the formation of a weaker electrolyte. And we know that ammonia is a weaker acid than hydro toric acid. So the equilibrium favors the products because it shifts towards the formation of weaker electrolytes. So we can say that products are favored well done. Let's continue with the second example. In the second example, we're given 333 tral propan 108. Let's go ahead and write it down F three C CH two CH two O minus and it reacts with fluorometer fchtoh. Now, from here, we can simply tell that our base is the one that has a negative charge because it can act as a proton acceptor and our acid is the protein donor. It is our alcohol because hygiene is bonded to electron oxygen base will capture hydrogen from acids. So one of our products will be F three cch two, another ch two and our oxygen gets bonded to hydrant to form an alcohol. And now fluorometer loses hydrant to become FC H2O minus. Now, bases produce conjugate assets. So the first product is our conjugate asset. And the second one will be the conjugate base because conjugate bases are produced from acids. Let's compare the asset strength. And essentially what we notice is that if we take our assets, we notice that we are given fluoro methanol, right? And 333 tral propane, 10 those are the assets that we want to compare. Now here we have to consider their conjugate base. I believe that it will be easier for us. So instead let's take the base and the conjugate base. The question is which base is more stable or essentially which one is a weaker electrolyte? The base on the reactant side contains three fluorine atoms, right? And the base on the right hand side contains one fluorine atom. Let's recall the inductive effect in these two structures. We have both a positive and a negative inductive effect for the base. On the left hand side, the positive inductive effect comes from the carbon chain, right? And the negative inductive effects comes from the three fluorine atoms. Now fluorine atoms are electron withdrawing, right So they are essentially decreasing the negative charge on oxygen, the greater the number of fluorine atoms, the lower the electron density and oxygen. So on the left hand side, we are expecting to have a weaker base. However, the three membered carbon chain essentially produces a positive inductive effect, which is increasing the electron density and oxygen more than one carbon on the product side. But the three fluorine atoms have a higher effect because they are highly electron as opposed to carbon atoms that are not that electro positive relative to oxygen. So we can say that the base on the left hand side is weaker than the base on the right hand side, since the positive and negative effect from the carbon atoms is negligible and therefore we are favoring the reactants because we have a weaker base on the left hand side of the equilibrium. So let's label our answers. Thank you for watching.

Key Concepts

Acid-Base Reaction Mechanism

Conjugate Acid-Base Pairs

Inductive Effect and Stabilization

Watch next