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Will you check my answers: High/lowest pH and How many different species are present in a solution?

Will you check my answers: High/lowest pH and How many different species are present in a solution? Topic: Turn case solutions
June 20, 2019 / By Debbie
Question: The following solutions contain a weak acid HA (pKa = 5) and its sodium salt, NaA Solution (a) contains: 3 HA and 5 A- Solution (b) contains: 4 HA and 4 A- Solution (c) contains: 4 HA and 5 A- Solution (d) contains: 6 HA and 4 A- Question 1: Which solution has the lowest pH? Answer: solution d because it has the most HA? Question 2: Which has the highest pH? Answer: solution a because it has the least HA? Question 3: How many different species (not including water and Na+ ion) are present after the addition of two H+ ions to this solution a? Answer: 2? Question 4: How many different species (not including water and Na+ ions) are present after the addition of two OH- ions to solution b? Answer: Not sure Thanks for taking the time to look over it.
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Best Answers: Will you check my answers: High/lowest pH and How many different species are present in a solution?

Britannia Britannia | 9 days ago
NO!! WRONG! Not even close! ** ** At least as I interpret the problem. It is extremely poor chemistry to claim that a solution contains 3 HA. WTF does that mean???!!! IDK. I am assuming it means that [HA] = 3 , specifically 3 Molar, which is the units of [....] last I heard. It is even worse when someone idiotically claims that two H⁺ ions are added. Slap your teacher up on side of the head, hard. Two ions would change the concentration insignificantly (unless, of course you are talking about attoliters). Almost criminal incompetence. So, ask your teacher YTF s/he thinks phrasing the problem that way is even acceptable. It is not. pKa is by definition -log(Ka) Ka is by definition (well, for beginner students) for the HA ⇌ H⁺ + A⁻ equilibrium, Ka = [H⁺][A⁻] ÷ [HA] You apparently think you can do it in your head. Good luck with that. You are given four different values for [A⁻] and [HA] you solve the equation for [H⁺], it is trivial arithmetic. In the case you are given, it turns out that answer 1 is d and 2 is a, but NOT for the reason you state!! For instance if d were 3 HA and 1 A⁻ it has the LEAST HA and yet is still lowest pH. Try it. And never do it the lazy way again. Q3 In solution a there is already HA, A⁻ and H⁺ (actually H₃O⁺ and H(H₂O) ͓⁺ ions, a bare proton is virtually never found, H₃O⁺ predominates). There is also (as you should know) some OH⁻ "floating around". Not much, but some. If two moles of H⁺ are added, then you could ignore the OH⁻, with confidence. So, I count 3 at least and if we wanted to stretch a point 4. Q4 Again assuming your teacher is an idiot, and that "two OH⁻ ions" means two moles of OH⁻, then you should assume all of it reacts with HA to form H₂O and A⁻ but you have 4 moles of HA, so that leaves 2 HA and 6 A⁻. And doesn't change the count, you still have HA, H⁺, A⁻ and a bit more OH⁻ But plugging into the equation to determine pH, you get a pretty acidic mix, so again the OH⁻ can be ignored. Note that in neither Q3 nor Q4 was the counter-ion identified. You can't add just H⁺, you can't add just OH⁻, both need a counter-ion. If you used, say HCl as the source of H⁺, the Cl⁻ ion would be added to the count. If you used, say KOH as the source of OH⁻, then the K⁺ ion would add to the count. You could add NaOH in Q4 and ignore the Na⁺, but there is nothing you can add that makes any sense in Q3 which would not change the count. Why couldn't you add HA as the source of H⁺ ? You could but that would increase not just the [H⁺], but both the [HA] and the [A⁻], too.
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Britannia Originally Answered: What species is best equipped to survive on an island of finite resources(excluding the human species)? Why?
the so called beneficial relationship between 2 different species called COMMENSALISM is the #1 option. since the resources in the island is finite, a special partnership is necessary for survival. here is where the philosophy ":2 heads are better than 1" is essentially applied. on the coast of the island, there's the relationship between the clownfish & the anemone. they protect each other from predators.. the clownfish is the only fish immune to the anemone's poison. on land, the cattle bird & the cow would survive because of commensalism too. taking care of each other. on air, the monarch butterflies have a beneficial partnership with the milkweed. another helpful relationship. since our relationship with our fellow human beings are far more complex than what i gave as examples.. these animals can do better in survival not because of the Law of Nature(survival) but more on cooperation & in the concept "live & let live".... some scientists are still bewildered for such a special bond could exist in the animal kingdon( there are actually more ).. but the message is clear.. "Survival of the fittest is not necessarily the best way to survive, but learn to be helpful to others too(even if they're different)" no man is an island, might as well share the island.. or die alone miserable
Britannia Originally Answered: What species is best equipped to survive on an island of finite resources(excluding the human species)? Why?
How about the technological offspring of the human species? Imagine a future in which "Artificial Life" or "Artificial Intelligence" will be more than advanced; it will also be self-sufficient in that it does not require organic nutrients to sustain its life. It could obtain energy from what today is viewed as inanimate matter. And, if that matter could be used to animate AI Life, wouldn't it be in a way animate matter? In that it could permit previously inanimate matter to animate it, wouldn't the AI species be in a novel way more animate than the human species that originated it? I think I should ask these questions at Yahoo Answers in the future. Thank you! You have helped me to finally think of some questions to ask.

Alice Alice
While I have no idea why, the answer to both Q3 and Q4 is 2. (I had this same one for my assignment.)
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Tyson Tyson
Jack white Bikini kill The Ramones The conflict maximum folk have heard of those even nevertheless it somewhat is alot diverse than the song at present.each ones heard of jack white yet his voice is basically so diverse
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Tyson Originally Answered: Can you check my math homework answers?
radius 7 ft volume 1436.03 ft yes radius 8 ft volume 2143.67 m yes radius 9 ft volume 3052.08 yes radius 4 ft volume 268 ft yes radius 2.5 in volume 65.42 in yes looks like you have the hang of it.

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