solution:
You need to find the frequency, and they have already given you the wavelength. And since you already know the speed of light, you can use formula (2) to answer this problem. Remember to convert the nano meters to meters because the speed of light is in meters. 

Answer:
Explanation:
2C₂H₅OH = C₄H₆ + 2H₂O + H₂
2 mole 1 mole
molecular weight of ethyl alcohol
mol weight of C₂H₅OH = 46 gm
mol weight of C₄H₆ 54 gm
540 gm of C₄H₆ = 10 mole
10 mole of C₄H₆ will require 20 mol of ethyl alcohol .
20 mole of ethyl alcohol = 20 x 46
= 920 gm
ethyl alcohol required = 920 gm .
Hard water<span>... is </span>water<span> that contains an appreciable quantity of dissolved minerals (like calcium and magnesium). </span>Soft water<span>... is treated </span>water<span> in which the only ion is sodium. As rainwater falls, it is naturally </span>soft<span>. </span>
There are two hydrogen and two oxygen molecules because the number next to the atomic number is how many there are.
Because lager objects have much more room for mass the smaller objects. take the earth as an example the earth is very big and has alot of mass in it which makes gravity that pulls us down when we jump up.