Answer:
Mass = 0.8 g
Explanation:
Given data:
Mass of oxygen = 3.2 g
Mass of CH₄ = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of O₂:
Number of moles = mass/molar mass
Number of moles = 3.2 g/ 32 g/mol
Number of moles = 0.1 mol
Now we will compare the moles of CH₄ and O₂.
O₂ : CH₄
2 : 1
0.1 : 1/2 = 0.1 = 0.05
Mass of CH₄:
Mass = number of moles × molar mass
Mass = 0.05 mol × 16 g/mol
Mass = 0.8 g
Answer:
177.8kJ/mol
Explanation:
In this reaction, the heat of decomposition is the same as the heat of formation. This is a decomposition reaction.
Given parameters:
ΔHf CaCO₃ = -1206.9kJ/mol
ΔHf CaO = −635.6 kJ/mol
ΔHf CO₂ = −393.5 kJ/mol
The heat of decomposition =
Sum of ΔHf of products - Sum of ΔHf of reactants
The equation of the reaction is shown below:
CaCO₃ → CaO + CO₂
The heat of decomposition = [ -635.6 + (-393.5)] - [−1206.9 ]
= -1029.1 + 1206.9
= 177.8kJ/mol
The answer is <span>Potassium cyanide</span>