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.
To solve this kinematics formula use the following equation:
Vf = Vi + at
Vf = 0 + (9.81 m/s^2)(3 seconds)
Vf = 29.43 m/s and or about 29.4 m/s of reported to 3 significant figures.
Volume of NaOH required to react = 145.5 ml
<h3>Further explanation</h3>
Reaction
CO₂(g)
+ 2 NaOH(aq) ⇒Na₂CO₃(aq) + H₂O(l)
The volume of CO₂ : 0.45 L
mol CO₂ at STP (O C, 1 atm) ⇒ at STP 1 mol gas 22.4 L :
From the equation, the mol ratio of CO₂ : NaOH = 1 : 2, so mol NaOH :
Then volume of NaOH :
Answer:
neutral groups of atoms formed by covalent bonds.
<span>4.50, 9.00, 36.00
First, count the number of atoms of each element in a single molecule of Mg(ClO4)2.
Mg = 1 atom
Cl = 1 * 2 = 2 atoms
O = 4 * 2 = 8 atoms
Now multiply the number of atoms of each element per molecule of the compound by the number of moles of the compound. So
Mg = 1 * 4.50 = 4.50
Cl = 2 * 4.50 = 9.00
O = 8 * 4.50 = 36.00
So the answer is
4.50, 9.00, 36.00</span>
