Hey there!
Given the reaction:
B + H⁺ => HB⁺
At half-equivalence point : [B] = [HB⁺]
=> [B] / [HB⁺] = 1
Henderson-Hasselbalch equation :
pH = pKa + log ( [B] ) / ( HB⁺)]
pH = 14 - pKb + log ( 1 )
pH = 14 - 7.95 + 0
pH = 6.05
Answer C
Hope that helps!
<span>Balance the equation
8Zn + S8 -----> 8ZnS
work out how much ZnS is possible if all of each reagent were to react. The reagent that produces the least product is the limiting reagent.
moles Zn = mass / molar mass = 4.88 g / 65.38 g/mol = 0.07464 moles
8 moles Zn reacts to form 8 moles ZnS
Therefore moles ZnS possible = moles Zn = 0.07464 moles
moles S8 = 5.03 g / 256.48 g/mol = 0.01961 mol
1 mole S8 reacts to form 8 moles ZnS
Therefore moles ZnS possible = 8 x moles S8 = 0.1569 mol
The amount of Zn provided gives the least ZnS, therefore Zn is the limiting reagent.
The theoretical yield is the maximum possible yield possible from the reagents provided. It is the amount of product that will form if all the limiting reagent reacts.
So in this case 4.88 g Zn yields 0.07464 mol ZnS
theoretical mass ZnS = molar mass x moles
= 97.44 g/mol x 0.07464 mol
= 7.27 g
% yield = actual yield / theoretical yield x 100/1
= 6.02 g / 7.27 g x 100/1
= 82.8 %</span>
K, ca, sc is the right answer. Take a look at table S of your chemistry reference table.
Answer:
.224 M
Explanation:
To begin, we need to find the molar mass of Na2S
To find Molarity, we use the equation M=moles/Liters of solution
We are given grams, so we must divide by the molar mass of Na2S to find moles.
- 8.76g Na2S / 78.05g/mol Na2S= .112 moles
Now we use our Molarity equation:
- .112 moles Na2S / .500L of solution = .224 M
Answer:
galaxy
Explanation:
because it contains the whole universe
