The industrial production of hydriodic acid takes place by treatment of iodine with hydrazine (N2H4): 2 I2 + N2H4 --> 4 HI + N2 (a) How many grams of I2 are needed to react with 36.7 g of (N2H4)?

Video transcript

All right. Hi everyone. So this question says to provide the balanced chemical equation that illustrates the synthesis of hydrogen gas using magnesium as the primary reactant. And in this case, we have four answer choices with the same reactants and the same products. However, we do have different molar equivalents listed for each. So lets go ahead and discuss this reaction because recall that when elemental magnesium illustrated as MG as a solid, when elemental magnesium or solid magnesium reacts with dilute hydrochloric acid, then the acid itself is going to ionize in water and react with our solid magnesium. So in this case, right, our HCL on our reactant side should be illustrated as aqueous to illustrate the fact that it should be dilute and ionized in a solution of water. Right? So when these two compounds react together, they combine to create hydrogen gas as well as a new salt involving our magnesium ions and our chloride ions. Now recall that magnesium belongs to group two A, meaning it's going to have a charge of plus two. Whereas chloride belonging to group seven A should have a charge of negative one. So magnesium has a charge of positive two and chloride has a charge of negative one. Therefore, to balance the charges of these two ions, then we should have two chloride ions for every one magnesium. Meaning our compound is going to be M GCL two and it is soluble in water, meaning it should be aqueous as well. So these are the combinations of reactants and products. However, on the bottom of the screen, I'm going to go ahead and write my equation down once more because I realized that I actually wrote down my products in the incorrect order as the answer choices, right. So I just want to make sure that what I'm writing matches the answer choices, right? So here is my chemical equation, but that doesn't necessarily mean it's going to be balanced because recall that an equation is considered balanced only when the number of atoms in the reactant side is equal to the number of atoms on the product side. And if you consider what we're, what we're starting off with here, that is actually not the case, right? This equation isn't balanced quite yet when you consider the number of chlorides on either side as well as the number of hydrogens on either side. Because in the react inside as of right now, there is one chloride and one hydrogen where it on the on the product side, there are two chlorides and there are two hydrogens. So this means that we have to increase the stoichiometry coefficient on the left side, considering there are less atoms of each, on the left side. So I can fix this by adding a sty meric coefficient of two in front of our aqueous HCL on the reactant side. Because what that does is go ahead and actually balance out the number of each type of atom that I happen to have in my equation. Because now on the left side, I have two chlorides and two hydrogens, which happens to match my numbers or might count on the right side. Whereas magnesium stays the same. And there you have it here is the balanced chemical equation which is one equivalent of solid magnesium combining with two equivalents of aqueous HCL, the form one equivalent of aqueous magnesium chloride and one equivalent of hydrogen gas, which means that our final answer is going to be option c in the multiple choice. So with that being said, thank you so very much for watching. And I hope you found this helpful.