One mole of water weighs 18 grams. H₂O is composed of 2H= 2 and 1 0=16 adding gives you 18. number of moles= mass/ Relative Molecular Mass
Therefore, mass= Relative Molecular Mass×number of moles
= 18×5 moles
= 90 grams
<u>Answer:</u> The wavelength of spectral line is 656 nm
<u>Explanation:</u>
To calculate the wavelength of light, we use Rydberg's Equation:
Where,
= Wavelength of radiation
= Rydberg's Constant = 
= Final energy level = 2
= Initial energy level = 3
Putting the values in above equation, we get:
Converting this into nanometers, we use the conversion factor:
So, 
Hence, the wavelength of spectral line is 656 nm
Ionic compounds are those compounds which form an ion or
dissociates into ions when placed in a solution. These compounds are made up of
a metal and non metal. From the choices, here are the ionic compounds:
na2so4
h2so4
cacl2
<span>ca3(po4)2</span>
Please refer to the attachment for a complete classification of your specified matter.
