Answer: Option (b) is the correct answer.
Explanation:
To find molarity, firstly we need to calculate number of moles as follows.
No. of moles =
=
=
Therefore, molratity is defines as number of moles of solute present in liter of solution.
Molarity =
=
=
Thus, we can conclude that molarity of solution is .
The reaction between metallic Magnesium and steam will be
As per balanced equation:
one mole of Mg will react with two moles of water to give one mole of magnesium hydroxide
Moles of Mg = Mass / atomic mass = 19.4/24 = 0.81
Moles of water = mass / molar mass = 14/18 =0.78
thus here for 0.81 moles of Mg we need twice the moles of water
However we have just 0.78 moles of water it means the limiting reagent is water
The moles of Mg reacted with water = 0.5 X 0.78 = 0.39 moles
moles of Mg left after reaction = 0.81-0.39= 0.42 moles
mass of Mg left (excess reagent) = moles X atomic mass = 0.42 X 24 = 10.08g
The moles of Mg(OH)2 formed = 0.39 moles
mass of Mg(OH)2 formed = moles X molar mass = 0.39 X 58 = 22.62g
Uhh idk sorry 17172928819191928++526219
Protons, neutrons..................................
The answer is B because that is how plants give off oxygen.