Buffer solutions consist of an aqueous solution of a weak acid and its conjugate base or a weak base and its conjugate acid. Buffer solutions are used to have better control of the pH of solutions.
An example of a weak acid and its conjugate base is acetic acid (CH3COOH) and sodium acetate (CH3COONa).
Answer:
Explanation:
Atomic radius is the measurement from the nucleus to the outer edge of the electron cloud.
As you go down a group (vertically) the atomic radius increases because more electron shells are added. As you go across a period horizontally, the atomic radius decreases.
If we look at the halogens group (17), we see they follow this order from top to bottom:
F - Fluorine
Cl - Chlorine
Br - Bromine
I - Iodine
Since it increases down the group, iodine must have the largest atomic radius.
Answer:
ΔH° = + 6.2 kJ
Explanation:
Fe₂O₃(s) + 3CO(g) –––––> 2 Fe(s) + 3 CO₂(g); ΔH° = –26.8 kJ ......... ( 1 )
FeO(s) + CO(g) –––––> Fe(s) + CO₂(g); ΔH° = –16.5 kJ .........( 2 )
Multiplying equation ( 2 ) by 2 and subtracting it from ( 1 )
Fe₂O₃(s) + 3CO(g) -2 FeO(s) - 2CO(g) ––> 2 Fe(s) + 3 CO₂(g) - 2Fe(s) - 2CO₂(g) ΔH° = –26.8 kJ - ( 2 x –16.5 kJ )
Fe₂O₃(s) + CO(g) -2 FeO(s)––> CO₂(g) ΔH° = –26.8 kJ + 33 kJ
Fe₂O₃(s) + CO(g) ––>2 FeO(s) +CO₂(g) ΔH° = + 6.2 kJ
Required ΔH° = + 6.2 kJ Ans .
53 neutrons
53 - 127=74 protons/electrons
