Answer:
OXYGEN
I don't know what to say for the 20 character limit
Δ H reaction = q / n where q: amount of heat released and n is number of moles of substance.
q = m . C . ΔT where:
m = mass of substance (g)
C = Specific heat capacity (4.18)
ΔT = change in temperature = 24.25 - 23.16 = 1.09
q = 1000 x 4.18 x 1.09 = 4556 J = 4.556 kJ
number of moles (n) = Molarity (M) x Volume (L)
= 0.185 M x 0.07 L = 0.01295 mole
Δ H = q / n = - (4.556 kJ / 0.01295 mole) = -351.8 kJ / mol
Note: it is exothermic reaction (-ve sign) i.e. temperature is raised
The answer is 3.
That is if an atom has 5 electrons in its outer shell, then it has 3 unpaired electrons.
As the outer shell have 1 s orbital too and that is fully filled and not available for bonding so it must have 3 unpaired electrons.
So the number of unpaired electrons in an atom that is having 5 electrons in its outer shell is 3.
The anwser I generated was “B”
