12 times breathe give 240 ml of pure 
. Each breathe gives 20 ml of .
Let us consider, volume of air per breathe= x ml.
Pure from inhaled air= 
ml and Pure from exhaled air= 
ml.
Pure from inhaled and exhaled air= 20 ml
So, + = 20
Therefore, x = 55.5 ml
So, volume of air per breath= 55.5 ml.
I hope it helps you ❤️❤️❤️❤️
Answer:
D. 1:1
Explanation:
For every 1 mole of chlorine (Cl₂), there is one mole of calcium chloride (CaCl₂).
So, the mole ratio of chlorine to calcium chloride is 1:1.
Hope this helps. :)
This is because oxygen (2.8.6) requires two electrons on its valence shell to attain stable configuration (2.8.8). Hydrogen (1) on the other hand requires one electron on its valence shell to attain stable configuration (2). Therefore in a covalent bond, it requires two hydrogen and one oxygen to share electrons and achieve stable configuration.
