Answer:
709 g
Step-by-step explanation:
a) Balanced equation
Normally, we would need a balanced chemical equation.
However, we can get by with a partial equation, as log as carbon atoms are balanced.
We know we will need an equation with masses and molar masses, so let’s <em>gather all the information</em> in one place.
M_r: 30.07 236.74
C₂H₆ + … ⟶ C₂Cl₆ + …
m/g: 90.0
(i) Calculate the moles of C₂H₆
n = 90.0 g C₂H₆ × (1 mol C₂H₆ /30.07 g C₂H₆)
= 2.993 mol C₂H₆
(ii) Calculate the moles of C₂Cl₆
The molar ratio is (1 mol C₂Cl₆/1 mol C₂H₆)
n = 2.993 mol C₂H₆ × (1 mol C₂Cl₆/1 mol C₂H₆)
= 2.993 mol C₂Cl₆
(iii) Calculate the mass of C₂Cl₆
m = 2.993 mol C₂Cl₆ × (236.74 g C₂Cl₆/1 mol C₂Cl₆)
m = 709 g C₂Cl₆
The reaction produces 709 g C₂Cl₆.
The available energy decreases as one moves upward in an energy pyramid.
<h3>Energy pyramid</h3>
The energy pyramid represents a model of how energy is transferred from one trophic level to another in ecosystems.
Energy is transferred from producers to primary consumers, from primary to secondary consumers, from secondary to tertiary consumers, and so on.
Only about 10% of the available energy in one trophic level is transferred to the next with the remaining 90% being lost as heat to the environment.
Thus, as one moves up the energy pyramid, the available energy decreases. This is why organisms at the higher end of the energy pyramid have to devise an efficient way of extracting energy from their foods.
More on energy pyramid can be found here: brainly.com/question/2515928
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See the sketch attached.
<h3>Explanation</h3>
The Lewis structure of a molecule describes
- the number of bonds it has,
- the source of electrons in each bond, and
- the position of any lone pairs of electrons.
Atoms are most stable when they have eight or no electrons in their valence shell (or two, in case of hydrogen.)
- Each oxygen atom contains six valence electrons. It demands <em>two</em> extra electrons to be chemically stable.
- Each sulfur atom contains six valence electrons. It demands <em>two </em> extra electrons to be chemically stable.
- Each hydrogen atom demands <em>one</em> extra electron to be stable.
H₂O contains two hydrogen atoms and one oxygen atom. It would take an extra 2 + 2 × 1 = 4 electrons for all its three atoms are stable. Atoms in an H₂O would achieve that need by sharing electrons. It would form a total of 4 / 2 = 2 O-H bonds.
Each O-H bond contains one electron from oxygen and one from hydrogen. Hydrogen has no electron left. Oxygen has six electrons. Two of them have went to the two O-H bonds. The remaining four become 4 / 2 = 2 lone pairs. The lone pairs repel the O-H bonds. By convention, they are placed on top of the two H atoms.
Similarly, atoms in a SO₂ molecule demands an extra 2 × 2 + 2 = 6 electrons for its three atoms to become chemically stable. It would form 6 / 2 = 3 chemical bonds. Loops are unlikely in molecules without carbon. As a result, one of the two O atoms would form two bonds with the S atom while the other form only one.
Atoms are unstable with an odd number of valence electrons. The S atom in SO₂ would have become unstable if it contribute one electron to each of the three bond. It would end up with 3 × 2 + 3 = 9 valence electrons. One possible solution is that it contributes two electrons in one particular bond. One of the three bonds would be a coordinate covalent bond, with both electrons in that bond from the S atom. In some textbooks this type of bonds are also known as dative bonds.
Dots and crosses denotes the origin of electrons in a bond. Use the same symbol for electrons from the same atom. Electrons from the oxygen atoms O are shown in blue in the sketch. They don't have to be colored.
The answer is A lithium sulfite