Answer:
Here's what I get
Explanation:
1. Balanced equation
HQ⁻ + CH₃-Br ⟶ HQ-CH₃ + Br⁻
(I must use HQ because the Brainly Editor thinks the O makes a forbidden word)
2. Mechanism
HQ⁻ + CH₃-Br ⟶[HQ···CH₃···Br]⁻⟶ HQ-CH₃ + Br⁻
A C B
The hydroxide ion attacks the back side of the carbon atom in the bromomethane (A).
At the same time as the Q-H bond starts to form, the C-Br bond starts to break.
At the half-way point, we have a high-energy intermediate (C) with partially formed C-O and C-Br bonds.
As the reaction proceeds further, the Br atom drops off to form the products — methanol and bromide ion (B).
3. Energy diagram
See the diagram below.
Your question is incomplete. However, I found a similar problem fromanother website as shown in the attached picture.
To solve this problem, you must know that at STP, the volume for any gas is 22.4 L/mol. So,
Moles O₂: 156.8 mL * 1 L/1000 mL* 1 mol/22.4 L = 0.007 moles
Mass calcium: 0.007 mol O₂ * 2 mol Ca/1 mol O₂ * 40 g/mol Ca =
<em> 0.56 g Ca</em>
Answer:
The correct answer is option A, that is, one valence electron in its third energy shell and option C, that is, 11 electrons and 11 protons.
Explanation:
The outermost electrons and the ones that take part in the process of bonding are termed as valence electrons. The atomic number of sodium is 11, thus, it possesses 11 protons and the atoms are neutral so it suggests that sodium has 11 electrons. By electronic configuration, it can be seen that in sodium, two electrons are present in the first shell, 8 in the second, and only one electron in the third shell, that is, 2.8.1. The electron present in the third shell is the valence electron.
Answer:
positive
positive
Explanation:
Entropy -
In a system, the randomness is measured by the term entropy .
Randomness basically refers as a form of energy that can not be used for any work.
The change in entropy is given by amount heat per change in temperature.
- When solid is converted to gas entropy increases,
As the molecules in solid state are tightly packed and has more force of attraction between the molecules, but as it is converted to gas, the force of attraction between the molecule decreases and hence entropy increases.
So,
The particles of the substance , if are tightly held by strong force of attraction will decrease the entropy ,
And
If the particles are loosely held , the entropy will increase , i.e. , positive entropy .
Similar with solid converting to liquid , the entropy will increases , i.e. , positive entropy .
Hence ,
The correct sign of entropy for both the process is positive .
