Question

What is the total mass of products formed when 16 grams of ch4?

Answer 1

The total mass of the products formed when 16 grams of methane (CH4) is combusted is equal to the mass of the reactants, which is also 16 grams, when not considering the massless product, heat.

Step-by-step explanation:

The student is asking about the total mass of products when 16 grams of methane (CH4) is combusted. Combustion of methane is represented by the balanced chemical equation CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) + energy. To find the total mass of the products, we would need to use stoichiometry to convert the mass of CH4 to moles, then use the balanced equation to find the moles of the products CO2 and H2O. Since mass is conserved, the total mass of reactants will equal the total mass of products. However, heat is also a product of the reaction, which is not measured by mass.

In this question, the student has mentioned specific molecular quantities, but since the aim is to determine the mass of products from 16 grams of methane, we don't need to consider these quantities. What we need is the concept that the mass of reactants equals the mass of products in a chemical reaction, where the mass of gaseous products is part of the overall calculation. Heat, despite being a part of the product side of the equation, does not contribute to the mass.

Therefore, the total mass of the CO2 and H2O produced from 16 grams of methane will also be 16 grams, neglecting energy. It is crucial to emphasize that this is a theoretical approach assuming complete combustion and no mass loss during the reaction.

Answer 2

When CH₄ is burnt in excess O₂ following products are formed,

CH₄ + 2 O₂ → CO₂ + 2 H₂O

According to equation 1 mole of CH₄ (16 g) reacts with 2 moles of O₂ to produce 1 mole of CO₂ and 2 moles of H₂O. Hence the products are,

1 mole of CO₂ and 2 moles of H₂O

Converting 1 mole CO₂ to grams;
As,
Mass = Moles × M.mass

Mass = 1 mol × 44 g.mol⁻¹

Mass = 40 g of CO₂

Converting 2 moles of H₂O to grams,

Mass = 2 mol × 18 g.mol⁻¹

Mass = 36 g of H₂O

Total grams of products;

Mass of CO₂ = 44 g
+ Mass of H₂O = 36 g
-------------
Total = 80 g of Product

Result:
80 grams of product is formed when 16 grams of CH₄ is burnt in excess of Oxygen.