<em>Answer:</em>
<em>Ello mate ! the answer is super simple it's option "A" Fe</em>
<em>Explanation:</em>
<em>Iron is a chemical element with symbol</em><em> "Fe"</em><em> and atomic number 26. It is a type of metal, that belongs to the first transition series and group 8 of the periodic table. It is by mass the most common element on Earth, forming much of Earth's outer and inner core.</em>
Isn't a chemical change like something that's not a physical change or physically changed but is something that uses natural chemicals? that's my guess sorry if it's wrong I think I'm wrong though
Question is incomplete. Complete question is attached below
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Answer: Option A: HCO3-(aq.)
Reason:
From the reaction, it can be seen that following reaction occurs in forward direct
HCO3-(aq) + H2O(l) → H2CO3(aq) + OH-(aq)
In above forward reaction, HCO3- accepts proton from H2O to generate H2CO3. Thus, according to Lowry and Bronsted theory of acid-base,
HCO3- is a base, while
H2CO3 is a conjugate acid.
Answers and Explanation:
a)- The chemical equation for the corresponden equilibrium of Ka1 is:
2. HNO2(aq)⇌H+(aq)+NO−2
Because Ka1 correspond to a dissociation equilibrium. Nitrous acid (HNO₂) losses a proton (H⁺) and gives the monovalent anion NO₂⁻.
b)- The relation between Ka and the free energy change (ΔG) is given by the following equation:
ΔG= ΔGº + RT ln Q
Where T is the temperature (T= 25ºc= 298 K) and R is the gases constant (8.314 J/K.mol)
At the equilibrium: ΔG=0 and Q= Ka. So, we can calculate ΔGº by introducing the value of Ka:
⇒ 0 = ΔGº + RT ln Ka
ΔGº= - RT ln Ka
ΔGº= -8.314 J/K.mol x 298 K x ln (4.5 10⁻⁴)
ΔGº= 19092.8 J/mol
c)- According to the previous demonstation, at equilibrium ΔG= 0.
d)- In a non-equilibrium condition, we have Q which is calculated with the concentrations of products and reactions in a non equilibrium state:
ΔG= ΔGº + RT ln Q
Q= ((H⁺) (NO₂⁻))/(HNO₂)
Q= ( (5.9 10⁻² M) x (6.7 10⁻⁴ M) ) / (0.21 M)
Q= 1.88 10⁻⁴
We know that ΔGº= 19092.8 J/mol, so:
ΔG= ΔGº + RT ln Q
ΔG= 19092.8 J/mol + (8.314 J/K.mol x 298 K x ln (1.88 10⁻⁴)
ΔG= -2162.4 J/mol
Notice that ΔG<0, so the process is spontaneous in that direction.
Answer:
D. Photosynthesis uses carbon dioxide while cellular produces carbon dioxide