Stoichiometry And Stoichiometric Calculations

Calculate number of molecules (n) for each of the given options, 

In 15 L of H₂ gas at STP,

n =

In 0.5 g of H₂ gas,

n =

In 5 L of N₂ gas at STP,

n =

In 10 g of O₂ gas,

n =

The maximum number of molecules are present in 15 L of H₂ gas at STP, hence option B is correct. 

Discover More From Concept: Stoichiometry 

Step 1: Understanding the Reaction
The chemical reaction between hydrogen and oxygen to form water is: This means that 2 moles of hydrogen gas ( ) react with 1 mole of oxygen gas ( ) to form 2 moles of water ( ).
Step 2: Molar Masses and Conversion
Molar mass of = 2 g/mol
Molar mass of = 18 g/mol
Step 3: Calculate the Amount of Water Produced
Given that 10 g of are used, we can calculate the moles of used: From the balanced equation, we know that for every 2 moles of , 2 moles of are produced. Therefore, 5 moles of will produce 5 moles of . Now, we calculate the mass of 5 moles of water:
Step 4: Conclusion
The amount of water produced is 90 g.