Answer:
The molar concentration of Fe²⁺ in the original solution is 1.33 molar
Explanation:
Moles of K₂Cr₂O₇ = Molarity x Volume (lit)
= 0.025 x 35.5 x 10⁻³
= 0.0008875
Cr₂O₇²⁻ + 6 Fe²⁺ + 14 H⁺ → 2 Cr³⁺ + 6 Fe³⁺ + 7 H₂O
From equation
1 mole K₂Cr₂O₇ used for the oxidation of 6 moles Fe²
0.0008875 mole K₂Cr₂O₇ used for the oxidation of =
= 0.005325 mole of Fe²
Molarity = 
Molar concentration of Fe² = 
= 1.33 molar
So molar concentration of Fe²⁺ in the original solution = 1.33 molar
Answer:
3s and 3p
Explanation:
From the question given above, the following data were obtained:
Electronic configuration =>
1s² 2s²2p⁶ 3s²3p⁴
Location of valence electron =?
From the electronic configuration given above, we can see clearly that the atom has three (3) shells.
Valence electron(s) are located at the outer most shell of an atom.
The outer most shell of the atom above is 3s and 3p.
Therefore, 3s and 3p will contain the valence electron(s)
Answer is ₂₀⁴²Ca.<span>
In AZX notation
A<span> - Represents the </span>mass number of atom.
Mass number = number of
protons + number of neutrons.
<span> It is shown at
the </span>above of the left side<span> of the
atom.</span>
<span> Here it is </span>42.
<span> </span>Z - Represents the atomic number.<span>
Atomic number = number of protons.
</span><span>It is shown at the</span> bottom line of the left side of the atom.<span>
</span>Here it is 20.<span>
X - </span>Represents the symbol of the atom.<span>
<span> </span></span>Here</span> X is Ca.<span>
</span>
