Hey there!:
Number of moles:
Molar Mass Al = 26.98 g/mol
n = mass / molar mass
n = 9.0 / 26.98
n = 0.3336 moles of Al
Given the reaction :
2 Al + Fe2O3 = Al2O3 + 2 Fe
From the equation, 2 moles of Al give off 849 kJ of heat :
Actual heat given off :
0.3336 / 2 * 849 =
0.3336 / 1698 = 1.4*10² Kj
Hope that helps!
Answer:
It should be silicon... I even googled it to see if I was correct and that’s what it says so can someone figure out why silicon is not an answer
Explanation:
An acid has a pH <7. 7 is the pH of a neutral substance, like water, and substance with a pH >7 are considered basic or alkaline.
Answer: Option (B) is the correct answer.
Explanation:
Degree of randomness of the molecules of a substance is known as entropy. More is the kinetic energy between the molecules of a substance more will be the degree of randomness.
Therefore, when a substance is present in a gaseous state then it has the maximum entropy. In liquid state, molecules are closer to each other so, there is less randomness between them.
On the other hand, in solid state molecules are much more closer to each other as they arr held by strong intermolecular forces of attraction. Therefore, they have very less entropy.
- When liquid water is formed from gaseous hydrogen and oxygen molecules then gas is changing into liquid. So, there is decrease in entropy.
- When
decomposes then the reaction will be as follows.
Since, 1 mole is producing 2 moles. This means that degree of randomness is increasing as both the molecules are present in gaseous form.
- In formation of a precipitate, aqueous solution is changing into solid state. Hence, degree of randomness is decreasing.
- Rusting of iron also leads to the formation of solid as it forms
.
Thus, we can conclude that decomposition of
gas to
gas is the process that is expected to have an increase in entropy.
Answer: a substance that increases the hydroxide ion concentration of a solution
Explanation: According to Arrhenius concept, an acid is a substance which donates hydronium ions
ions when dissolved in water and base is a substance which donates hydroxide ions
ions in water.
According to the Bronsted Lowry conjugate acid-base pair, an acid is a substance that donates protons and a base is a substance that accepts protons.
According to Lewis concept, an acid is the substance which accepts electron pairs and abase is a substance which donates electron pairs.
Thus a substance that increases the hydroxide ion concentration of a solution is an Arrhenius base.