Answer:
- The option <u><em>B) Fe₂O₃ (s) + 3C(s) → 2Fe(s) + 3CO₂(g),</em></u> because the reactants are only solid units and the products contain gas molecules.
Explanation:
A <em>positive entropy change</em> means that the entropy of the products is greater than the entropy of the reactants.
Entropy in a measure of the radomness or disorder of the system.
Let's see every reaction:
<u />
<u>A) 4NO₂ (g) + 2 H₂O (l) + O₂ (g) → 4 HNO₃ (aq)</u>
Since 5 molecules of a gas (high disorder) combines with 2 molecules of liquid to produce 4 units of aqueous HNO₃ you may expect that the product is more ordered than the reactants, which means that the change in entropy is negative (the entropy decreases).
<u />
<u>B) Fe₂O₃ (s) + 3C(s) → 2Fe(s) + 3CO₂(g)</u>
The left side (reactants) show only solid substances which is a highly ordered arrangement while the right side (products) show the formation a solid (ordered arrangement) and a gas (highly disoredered arrangement), so you can predict the increase of the system entropy, i.e. a positive entropy change.
The <u>equation C)</u> shows the combination of 12 gas molecules to produce 1 solid and 6 gas molecules, so you can expect that the entropy will decrease, i.e. a negative entropy change.
For <u>equation D)</u> the products include solid and gas reactants while the product is just one unit of solid substance, letting you to predict a negative entropy change.
D will because water just turns from liquid to a gas by adding heat. That is a physical change. The other equations are chemical changes.
Conduction
Convection
Radiation
Explanation:
The main types of heat transfer are heat transfer by conduction, convection and by radiation.
These forms of heat transfer has different modes of application.
- Conduction is a form of heat transfer in solids. It requires a material medium to dissipate. Here, heat flows from a hot end to a cold end.
- Convection is a form of heat transfer in fluids i.e liquids and gases. In convection, heat is transferred due to density differences between heated fluids.
- Radiation does not involve material medium. It uses the electromagnetic waves to dissipate heat.
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Conduction brainly.com/question/1140127
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Answer:
conversion of sunlight to cloraphil
Explanation:
plants absorb sun and convert it to energy
The natural abundance of bromine in general in nature is 100%.
This means that:
the natural abundance of Br-79 + the natural abundance of Br-80 = 100
We know that the natural abundance of Br-79 is 50.69%. This means that the natural abundance of Br-80 is the rest of the 100%.
Natural abundance of Br-80 = 100% - 50.69% = 49.31%