Answer:
A. K
Step-by-step explanation:
Remember the trends in the Periodic Table:
- Atomic radii <em>decrease</em> from left to right across a Period.
- Atomic radii <em>increase</em> from top to bottom in a Group.
- Ionic radii of metal cations are <em>smaller</em> than those of their atoms.
Thus, the largest atoms are in the lower left corner of the Periodic Table.
The diagram below shows that K is closest to the lower left, so it is the largest atom. It is also larger than any of the cations.
The pH a 0.25 m solution of C₆H₅NH₂ is equal to 3.13.
<h3>How do we calculate pH of weak base?</h3>
pH of the weak base will be calculate by using the Henderson Hasselbalch equation as:
pH = pKb + log([HB⁺]/[B])
pKb = -log(1.8×10⁻⁶) = 5.7
Chemical reaction for C₆H₅NH₂ is:
C₆H₅NH₂ + H₂O → C₆H₅NH₃⁺ + OH⁻
Initial: 0.25 0 0
Change: -x x x
Equilibrium: 0.25-x x x
Base dissociation constant will be calculated as:
Kb = [C₆H₅NH₃⁺][OH⁻] / [C₆H₅NH₂]
Kb = x² / 0.25 - x
x is very small as compared to 0.25, so we neglect x from that term and by putting value of Kb, then the equation becomes:
1.8×10⁻⁶ = x² / 0.25
x² = (1.8×10⁻⁶)(0.25)
x = 0.67×10⁻³ M = [C₆H₅NH₃⁺]
On putting all these values on the above equation of pH, we get
pH = 5.7 + log(0.67×10⁻³/0.25)
pH = 3.13
Hence pH of the solution is 3.13.
To know more about Henderson Hasselbalch equation, visit the below link:
brainly.com/question/13651361
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when iron and oxygen the reactin form Fe2O3 balance equation for this is <span>4Fe + 3O2---> 2Fe2O3
9moles of O2 are needed to produce 6mol of Fe2O3 since the ratio of oxygen to iron(II)oxide is 3:2
hope its help</span>
