Calculate the pH of solutions prepared by:
(a) Dissolving 0.20 g...

Question

Calculate the pH of solutions prepared by: 
(a) Dissolving 0.20 g of sodium oxide in water to give 
100.0 mL of solution.

Accepted Answer

well every once in this problem, we want to find the ph of the solution that involves barium oxide and water. So barium oxide reacts with water to produce barium hydroxide which is B. A. O. H two. And this is a compound that will make the solution basic. So for the reaction here, what's going on? Is that we again we have B. O. Reacting with H. 202, yield B. A. O. H. Two. So stop that. I'm gonna go ahead and take to find the P. H. Is by their long but definitely will be very useful for the future. So first up I'm gonna take is find the moles of our products. So be A O. H. Two that's produced. And then from there we go ahead and find the polarity of our products. So be A. O. H. Two as well as the concentration of O. H minus from the concentration of O H minus. We can then find R. P. O. H. Value and from our P. O. H value we can find our ph value which is the ultimate goal of this problem. So we need the molar mass of B. A. O. We're gonna go ahead and use the pr table for this. So again, we're finding the molar mass of B. A. O. So for barium here, that's equal 137.3-7 for auction. This is 15.9994. Taking the sum of this, we get the value of 53.3264 units being grams per mole. So not calculate for the mass of our B A O H two is our product. We're starting off with the grams or the mass of bearing Maaseide was given to us in the problem. So we have 0. Or rather 0.845g of barium oxide For every 150 ml of water. In this case, even though we're given this amount was actually leave out, these leaders were just dealing with our barium oxide. So we're gonna go ahead and notify this with the molar mass of barium oxide to give us the moles. So for every one mole of B A. O. We have a 153.3264 g of b. a. o. Now what we can do is use the multiple ratio to convert from moles of barium oxide into molds of our products. So we have a 1 to 1 ratio here according to this equation. So for every one mole of our product, so B A H two, we need or have one mole of B A. Oh, so for units cancelation, we see that the grams of B O cancels and the moles of B. O canceled Leaving us with the units of just moles of our product, which is what we want. So once you put that into a calculator, receive that my value is equal to 0.00551112. Most of Our Products of BA OH. two. So B O H two is a strong base. And associates to give two moles of O H minus ions per mole of our product. So this reaction is B A O H. Two. And this again yields are B A two plus and R 20 h minus is Calgary for my concentration of O H minus. This equals to well we have the mass already of our products, that's 0. moles of B A. O. H two. Now we can go ahead and divide by the millions of solutions. So that's 150 mL Of solution, we can convert our melodies into leaders. So for every 1000 ml we have one leader and then doing a multi mole ratio. Here we have two moles of R O H minus For every one mole of our products of BAOH two. Alright, for our units cancelation, we see that Ml leaders will cancel the most of our product, will cancel leaving us with just the moles of O. H minus over leaders. Which is this the units of castle Orca concentration. So this equals two, then 0. Molars. So now using this concentration we can actually solve for POH. So for P O H. This equation is equal to negative log of the concentration of O H minus. So we of course offer the concentration of O. H minus. Well, basically plug this value in to our equation. That value is 0. molars. So this gives me that my p. o. h. value is equal to 1.13383. So for my ph value, finally we know that my ph plus my P. O. H. Give us a value of 14. So we have course the value of P. O. H. So let's go ahead and put this in again. That's 1.13383 and equals 14. Subtract both sides of equation by 1.13383 to give us the isolate ph value. So ph is then equal to 12.866. So this right here is going to be my final answer for this problem regarding our ph

Calculate the pH of solutions prepared by: (a) Dissolving 0.20 g of sodium oxide in water to give 100.0 mL of solution.

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