When the sun is low in the sky, light rays pass horizontally through more of the lower atmosphere to reach the earth's surface or an observer's eye. ... Because short-wavelength blue and green light are scattered more than red and yellow light, rainbows at times of sunrise and sunset often display the brightest reds.
<u>Answer:</u> The molarity of citric acid that is commercially available lemon juice is 0.416 M
<u>Explanation:</u>
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

Hence, the molarity of citric acid that is commercially available lemon juice is 0.416 M
A)1.75×3 moles of carbon monoxide
B)2:3
A)each mole of ferric oxide requires 3 moles of carbon monoxide. Therefore 1.75 moles requires 1.75 ×3 moles of carbon monoxide
I think c is used in electric power plants.