Answer:
1.58x10⁻⁵
2.51x10⁻⁸
0.0126
63.10
Explanation:
Phenolphthalein acts like a weak acid, so in aqueous solution, it has an acid form HIn, and the conjugate base In-, and the pH of it can be calculated by the Handerson-Halsebach equation:
pH = pKa + log[In-]/[HIn]
pKa = -logKa, and Ka is the equilibrium constant of the dissociation of the acid. [X] is the concentrantion of X. Thus,
i) pH = 4.9
4.9 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = - 4.8
[In-]/[HIn] = 
[In-]/[HIn] = 1.58x10⁻⁵
ii) pH = 2.1
2.1 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = -7.6
[In-]/[HIn] = 
[In-]/[HIn] = 2.51x10⁻⁸
iii) pH = 7.8
7.8 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = -1.9
[In-]/[HIn] = 
[In-]/[HIn] = 0.0126
iv) pH = 11.5
11.5 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = 1.8
[In-]/[HIn] = 
[In-]/[HIn] = 63.10
Answer:
i see lot of peeps like anime and so do i zero two and naruto
Explanation:
Answ
Explanation:
that is like a satelite it helps detect signals from like outer space and things
I’m sorry I don’t understand if you can may you say it in English?
Answer:
a = 4
b = 3
Explanation:
<u>SOLUTION :-</u>
Balance it by using 'hit & trial' method , and you'll get the answer :-
2Fe₂O + 3C → <u>4</u>Fe + <u>3</u>CO₂
⇒ a = 4 ; b = 3
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<u>VERIFICATION :-</u>
<em>In reactant side of equation :-</em>
- Number of atoms in Fe = 2×2 = 4
- Number of atoms in O = 2×3 = 6
- Number of atoms in C = 3×1 = 3
<em>In product side of equation :-</em>
- Number of atoms in Fe = 4×1 = 4
- Number of atoms in C = 3×1 = 3
- Number of atoms in O = 3×2 = 6
Number of atoms of each element is equal in both reactant & product side of equation. Hence , the equation is balanced.
