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
Answer:
Both liquids and gases are fluids = true
Explanation:
firstly find for the molar mass of kcl and molar mass of k
and then
molar mass of k = x
molar mass of kcl= 40
cross mutiply and then simplify you will get your answer
<u>Answer:</u> The balanced chemical equation is written below.
<u>Explanation:</u>
Double displacement reaction is defined as the reaction in which exchange of ions takes place.

Precipitation reaction is defined as the reaction in which an insoluble salt is formed when two solutions are mixed containing soluble substances. The insoluble salt settles down at the bottom of the reaction mixture.
When nickel (II) chloride reacts with silver (I) nitrate, it leads to the formation of white precipitate of silver chloride and an aqueous solution of nickel (II) nitrate.
The balanced chemical equation for the above reaction follows:

By Stoichiometry of the reaction:
1 mole of aqueous solution of nickel (II) chloride reacts with 2 moles of aqueous solution of silver (I) nitrate to produce 2 moles of solid silver chloride and 1 moles of aqueous solution of nickel (II) nitrate
Hence, the balanced chemical equation is written above.