Answer: There are 0.000043 moles of melatonin.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
given mass = 10 mg = 0.01 g
molar mass of 
= 232.28 g
Thus there are 0.000043 moles of melatonin
It’s Benzene, I do believe :) hope this helped, good luck!
The formula for the self ionization of water is 2H₂O(l)⇄H₃O⁺(aq)+OH⁻(aq)
The hydronium (H₃O⁺) is usually just referred to as a hydrogen ion or a proton (H⁺) and hydroxide (OH⁻) doesn't have another name that I am aware of. These ions do stay in solution. However the concentrations are really small and the equilibrium constant (K(w)) is 1×10⁻¹⁴.
I hope this helps. Let me know if anything is unclear.
<span>Population growth is limited in ecosystems because of lack of resources. If there were unlimited resources, a population would grow exponentially.
For example, if a single bacterium were placed in a petri dish and was given unlimited resources, it would multiply to cover the entire world within several days.
Unfortunately, resources are limited, so populations are too.</span>
Answer:
H3PO4 is stronger than H2PO4- because
H3PO4 dissociation constant is 6.9×10^-3
H2PO4^- dissociation constant is 6.2×10^-8
