The empirical formula is C₇H₆O₂.
Assume that you have 100 g of the compound.
Then you have 68.84 g C and 4.962 g H.
Mass of O = (100 – 68.84 – 4.962) g = 26.20 g O.
Now, we must convert these masses to moles and find their ratios.
From here on, I like to summarize the calculations in a table.
<u>Element</u> <u>Mass/g</u> <u>Moles</u> <u>Ratio</u> <u> ×2</u> <u>Integers</u>
C 68.84 5.732 3.501 7.001 7
H 4.962 4.923 3.006 6.012 6
O 26.20 1.638 1 2 2
The empirical formula is C₇H₆O₂.
Answer:
ΔH°rxn = -827.5 kJ
Explanation:
Let's consider the following balanced equation.
2 PbS(s) + 3 O₂(g) → 2 PbO(s) + 2 SO₂(g)
We can calculate the standard enthalpy of reaction (ΔH°rxn) from the standard enthalpies of formation (ΔH°f) using the following expression.
ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g)
)] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g)
)]
ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g)
)] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g)
)]
ΔH°rxn = [2 mol × (-217.32 kJ/mol) + 2 mol × (-296.83)] - [2 mol × (-100.4) + 3 mol × 0 kJ/mol]
ΔH°rxn = -827.5 kJ
Answer:
a) HNO3
b) 26.8g (3 s.f.)
c) 1.29g (3 s.f.)
Please see the attached pictures for full solution.
To balance an equation, ensure that the number of atoms for each element is the same on both sides.
Answer:
Verdadero (True).
Explanation:
Después de la desintegración del citado virreinato, los nuevos Estados intentaron establecer sus fronteras, a menudo a través de guerras e invasiones. Cabe destacar la invasión brasileña de Uruguay o la Guerra de la Triple Alianza. En menor medida, lo hicieron a través de tratados internacionales. (After the disolution of the viceroyalship described above, the new States attempted to establish their frontier usually by wars and invasions. It is to highlight the Brazilian invasion of Uruguay or the Triple Alliance' War. In a lesser extent, they made it through international treaties.)
Solar: rays from the sun shine on solar pannels creating energy which is a renewable energy.
Water: water stored at a dam flows through turbines creating energy which is a renewable energy
Fossil fuels: fossil fuels are extracted from the ground the burned to create energy and this is a nonrenewable resource.
Hope this helps :)
