Methane is the compound CH4, and burning it uses the reaction:
CH4 + O2 -> CO2 + H2O, which is rather exothermic. To find the heat released by burning a certain amount of the substance, you should look at the bond enthalpy of each compound, and then compare the values before and after the reaction. In methane, there are 4 C-H bonds, which have bond energy of 416 kj/mol, resulting in a total bond energy of 1664 kj/mol. O2 is 494 kj/mol. Therefore we have a total of 2080 kj/mol on the left side. On the right side we have CO2, which has 2 C=O bonds, each at 799 kj/mol each, resulting in 1598 kj/mol, and H2O has 2 O-H bonds, at 459kj/mol each, resulting in a total of 2516 kj/mol on the right hand side. Now, this may be confusing because the left hand side seems to have less heat than the right, but you just need to remember: making minus breaking, which results in a total change of 436kj/mol heat evolved.
Now it is a simple matter of find the mols of CH4 reacted, using n=m/mr.
n = 9.5/16.042 = 0.592195 mol
Therefore, if we reacted 0.592195 mol, and we produced 436 kj for one mol, the total amount of energy evolved was 436*<span>0.592195 kj, or 258.197 kj.</span>
<h3><u> Answer</u>;</h3>
= 4.0 L
<h3><u>Explanation;</u></h3>
Boyle's law states that the volume of a fixed mass of a gas is inversely proportional to pressure at a constant temperature.
Therefore; <em>Volume α 1/pressure</em>
<em>Mathematically; V α 1/P</em>
<em>V = kP, where k is a constant;</em>
<em>P1V1 = P2V2</em>
<em>V1 = 0.5 l, P1 =203 kPa, P2 = 25.4 kPa</em>
<em>V2 = (0.5 × 203 )/25.4 </em>
<em> = 3.996 </em>
<em> ≈ </em><em><u>4.0 L</u></em>
Hello,
Here is your answer:
The proper answer to this question is A "sand". Sand is a mixture!
Your answer is A.
If you need anymore help feel free to ask me!
Hope this helps!
The atomic number of an element tells you the number of protons within said element.
Answer:
Option d. 0.10 m Cr₂(SO₄)₃
Explanation:
Formula for the osmotic pressure is determined as:
π = M . R . T . i
So you have to take account the i (Van't Hoff factor, numbers of ions dissolved)
Urea is an organic compound, so the i value is 1
Zync acetate can be dissociated:
Zn(CH₃COO)₂ → 1Zn²⁺ + 2CH₃COO⁻
In this case, the i is 3. (you see, the stoichiometry of ions)
Cr₂(SO₄)₃ → 0.10 m
Chromium sulfate is dissociated:
Cr₂(SO₄)₃ → 2Cr³⁺ + 3SO₄⁻²
i = 5
BaI₂ → 0.16 m
BaI₂ → 1Ba²⁺ + 2I⁻
i = 3
