If 30mL H2 and 20mL Of O2 react To Form Water, What Is Left At The End Of The Reaction? 

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If 30mL H2 and 20mL of O2 react to form water, what is left at the end of the reaction? 


Correct option is

mL O2


2 H2  + O2 → 2 H2O

2 mL    1 mL

2 mL of H2 react with 1 mol of O2. Hence, 30 mL of H2 will react with 15 mL of O2.



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