The answer would be D because from my research it's the only one that didn't have a catalyst
All chemical reactions follow the law of conservation of mass. This means that the number of atoms of a specie before the reaction must equal to the number of atoms of that specie after that reaction. The only change that occurs in chemical reactions is the breaking and formation of chemical bonds, due to which energy may be released or absorbed.
Answer:
The solution is 4.93 molal
Explanation:
We assume that solution is aqueous.
We need to apply the colligative property of elevation of boiling point:
ΔT = Kb . m . i
ΔT = Boiling T° of solution - Boiling T° of pure solvent
110.1°C - 100°C = 10.1°C
Kb = 0.512 °C/m
m = molality → unknown
i = Van't Hoff factor (numbers of ions dissolved)
We assume 100 % dissociation: CoCl₃ → Co³⁺ + 3Cl⁻ i = 4
We have 1 mol of Co³⁺ + 3 moles of chlorides
We replace data → 10.1°C = 0.512°C/m . m . 4
10.1°C / (0.512 m/°C . 4) = m → 4.93
The balanced equation for the reaction is
C₃H₈ + 5O₂ → 3CO₂ + 4H₂<span>O
Moles (mol) = mass (g) / molar mass (g/mol)
Mass of the </span>C₃H₈ = 0.025 g
Molar mass of C₃H₈ = <span>44.1 g/mol
Hence, moles of </span>C₃H₈ = 0.025 g / 44.1 g/mol = 5.67 x 10⁻⁴ mol
The stoichiometric ratio between C₃H₈ and O₂ is 1 : 5.
Hence, moles of O₂ = moles of C₃H₈ x 5
= 5.67 x 10⁻⁴ mol x 5
= 2.835 x 10⁻³ mol
Molar mass of O₂ = <span>32.00 g/mol
Hence, mass of O</span>₂ = moles x molar mass
= 2.835 x 10⁻³ mol x 32.00 g/mol
= 0.09072 g
Hence, needed O₂ for the reaction is 0.09072 g.