Empirical formula of caffeine is C₈H₁₀N₄O₂.
In 1 mol of caffeine we have 10 mol of hydrogen.
In 2,8 mol of caffeine we have x mol of hydrogen.
x = 2,8 mol * 10 mol / 1 mol = 28 mol
ANSWER: There are 28 mol of hydrogen.
:-) ;-)
Reactivity trends of halogen:
1) Melting point and boiling points increased down the
group
2) Colour becomes darker.
E.g. Fluorine (pale yellow)
Chlorine (yellowish-green)
Bromine (reddish-brown)
Iodine (purplish-black)
Astatine (black)
3) The reactivity decreases down the group.
Reactivity:
F > Cl > Br > I > At
Answer:
I think c biological processes
Answer:
The coordination sphere of a complex consists of <u><em>the central metal ion and the ligands bonded to it.</em></u>
Explanation:
The Coordination Compounds are sets of a central metal ion attached to a group of molecules or ions that surround it. They are also called metal complexes or simply complexes. Then they are compounds that have a central atom surrounded by a group of molecules or ions, the latter called ligands.
The central atom must have empty orbitals capable of accepting pairs of electrons, with the transition metals being the ones with the greatest tendency. Because of this, they can act as Lewis acids (electron pair acceptors). The ligands have unshared electron pairs, then acting as Lewis bases (electron pair donors).
When forming a complex, it is said that the ligands coordinate to the metal and the central metal and the ligands attached to it constitute the coordination sphere of the complex.
Finally, <u><em>the coordination sphere of a complex consists of the central metal ion and the ligands bonded to it.</em></u>
Compounds Na₂SO₄ and NaCl are mixed together are we are asked to find the concentration of Na⁺ in the mixture
Na₂SO₄ ---> 2 Na⁺ + SO₄³⁻
1 mol of Na₂SO₄ gives out 2 mol of Na⁺ ions
the number of Na₂SO₄ moles added - 0.800 M/1000 * 100 ml
= 0.08 mol
therefore number of Na⁺ ions from Na₂SO₄ = 0.08 * 2 = 0.16 mol
NaCl ----> Na⁺ + Cl⁻
1 mol of NaCl gives 1 mol of Na⁺ ions
number of NaCl moles added = 1.20 M/1000 * 200 ml
= 0.24 mol
number of Na⁺ ions from NaCl = 0.24 mol
total number of Na⁺ ions in the mixture = 0.16 mol + 0.24 mol = 0.4 mol
as stated the volumes are additive,
therefore total volume = 100 ml + 200 ml = 300 ml
the concentration of Na⁺ ions = number of moles / volume
= 0.4 mol/ 0.3 dm³
concentration of Na⁺ = 1.33 mol/dm³
