HCl ----------> H(+) + Cl(-)
0,0045-x.........x...........x
0..................0,0045...0,0045
pH = -log[H+]
pH = -log[0,0045]
pH = 2,347
pOH = 14-pH
pOH = 14-2,347
pOH = 11,653
pOH = -log[OH-]
[OH-] = 10^-pOH
[OH-] = 10^-11,653
[OH-] = 2,2233·10^-12 mol/dm³
Answer is: there are 216 moles od water.
Chemical reaction: 2H₂ + O₂ → 2H₂O.
n(H₂) = 226 mol.
n(O₂) = 108 mol; limiting reactant.
From chemical reaction: n(O₂) : n(H₂O) = 1 : 2.
n(H₂O) = 2 · n(O₂).
n(H₂O) = 2 · 108 mol.
n(H₂O) = 216 mol.
n - amount of substance.
The atom is the smallest particle of an element that retains it's characteristics. Sub-atomic particles such as protons, neutrons and electrons form the atom and it is the amount of each of these sub-atomic particles that make the element that element.
I would go with b and c if you can choose both
The second law of thermodynamics states that in a reversible process, the entropy of the universe is constant, whereas in an irreversible process, such as the transfer of heat from a hot object to a cold object, the entropy of the universe increases
