Question

Given the following chemical equations:

I. CH₄ ​​ + 2O₂ ​​ → CO₂ + 2H₂​​O (1.25 L of CH₄ with density = 0.656 g/L)

II. 6CO₂ + 6H₂​​O → C₆​​H₁₂​​O₆ (7.25 g of CO₂ ​​)

Which equation will have the highest number of carbon atoms produced based on the information given next to each chemical equation?

A. I

B. II

Answer 1

I. CH4 ​​ + 2O2 ​​ → CO2 + 2H2​​O (1.25 L of CH4 with density = 0.656 g/L; MW of CH4= 16 & MW of CO2= 44; atomic wt of C=12)

We know, 12 of carbon contain 6.023 x 10 ²³ atoms of carbon

1 mole of CH4 will produce 1 mole CO2

or, 16 g of CH4 will produce 44 g of CO2

or, (16/ 0.656 )= 24.39 L of CH4 will produce 12 g of carbon

or 24.39 L of CH4 will produce 6.023 x 10 ²³ of carbon atoms

So, 1.25 L of CH4 will produce [(6.023 x 1.25 x 10 ²³ ) / 24.39] = 0.308 x 10 ²³ of carbon atoms

II. 6CO2 + 6H2​​O → C6​​H12​​O6 (7.25 g of CO2 ​​)

6 mole of CO2 will produce 1 mole C6​​H12​​O6

or, 6 x 44 = 264 g of CO2 will produce 6 x 12 = 72 g of carbon

So, 7.25 g of CO2 will produce (72 x 7.25) / 264 = 1.977g of carbon

Now , 12 g carbon contain 6.023 x 10 ²³ of carbon atoms

So, 1.977 g of carbon contain [(6.023 x 1.977 x 10 ²³ ) / 12 = 0.99 x 10 ²³ of carbon atoms

Therefore, highest number of carbon atoms produced by equation II ( Option B is the correct option)