Answer:
Explanation:
The law of conservation of mass states that "mass in a system remains constant and that the mass of the product is remains the same as that of the reactants".
Law of conservation of energy states that "energy is neither created nor destroyed in the course of chemical or physical change but can be transformed from one form to another".
Let us properly write the equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
For the conservation of mass:
C has 1mole on both sides
H has 4mole on both sides
O has 4 mole on both sides
For energy, during combustion process, the methane CH₄ burns to liberate heat energy. This is an energy conversion process in which chemical energy in methane releases heat energy.
Answer:
Fe + 3CuNO₃ → Fe(NO₃)₃ + 3Cu
Explanation:
- Copper (I) nitrate = CuNO₃ (Nitrate, NO₃⁻, always has a charge of -1).
- Iron (III) nitrate = Fe(NO₃)₃ (That way the compound has an overall neutral charge)
Writing the equation using symbols leaves us with:
- Fe + CuNO₃ → Fe(NO₃)₃ + Cu
<em>It is not balanced yet</em>. Now we <u>balance the NO₃ species on the left side</u>:
- Fe + 3CuNO₃ → Fe(NO₃)₃ + Cu
Finally we<u> balance the Cu species on the right side</u>:
- Fe + 3CuNO₃ → Fe(NO₃)₃ + 3Cu
Answer:
- <em>Option d. Its empirical formula is CH</em><em>₂</em><em>.</em>
Explanation:
The percent composition of the compound allow you to calculate the empirical formula of the compound but is not enough to calculate either the molar mass or the molecular formula. So, since now you can discard options b. and c.
Telling that it is a hydrocarbon (option e.) is true but very vague compared with finding the empirical formula. So, you can also discard the option e.
The fact that the product has a triple bond cannot be concluded from the percent composition, you should find the molecular formula to assert whether it contains or not a triple bond. So, you could discard option a., which lets you only with choice d.
Let us find the empirical formula to be certain that it is CH₂.
1. <u>First, assume a basis of 100 g of compound</u>:
- H: 14.5% × 100 g = 14.0 g
- C: 85.5% × 100 g = 85.5 g
2. <u>Divide each element by its atomic mass to find number of moles</u>:
- H: 14.0 g / 1.008 g/mol = 14.38 mol
- C: 85.5 g / 12.011 g/mol = 7.12 mol
3. <u>Divide both amounts by the smallest number, to find the mole ratio</u>:
- H: 14.38 mol / 7.12 mol ≈ 2
- C: 7.12 mol / 7.12 mol = 1.
Hence, the ratio is 2:1 and the empirical formula is CH₂.
Answer: KMnO4-
Explanation:
You're looking at one potassium plus a polyatomic ion.
So K plus MnO4, equals:
KMnO4-
It also has a molar mass of 158.04 g/mol, I don't know if you need that, but I thought it would be nice to include it.
