Answer:
The electrons are lost from the valence shell (outermost electron shell) of the atom.
Explanation:
This is able to be inferred not only because valence electrons being lost first is a trend but also because the atom in question has actually 3 valence electrons (13-2-8 = 3).
Answer:
The amount of work done on the system is 18234 J and the final positive sign means that this work corresponds to an increase in internal energy of the gas.
Explanation:
Thermodynamic work is called the transfer of energy between the system and the environment by methods that do not depend on the difference in temperatures between the two. When a system is compressed or expanded, a thermodynamic work is produced which is called pressure-volume work (p - v).
The pressure-volume work done by a system that compresses or expands at constant pressure is given by the expression:
W system= -p*∆V
Where:
- W system: Work exchanged by the system with the environment. Its unit of measure in the International System is the joule (J)
- p: Pressure. Its unit of measurement in the International System is the pascal (Pa)
- ∆V: Volume variation (∆V = Vf - Vi). Its unit of measurement in the International System is cubic meter (m³)
In this case:
- p= 10 atm= 1.013*10⁶ Pa (being 1 atm= 101325 Pa)
- ΔV= 2 L- 20 L= -18 L= -0.018 m³ (being 1 L=0.001 m³)
Replacing:
W system= -1.013*10⁶ Pa* (-0.018 m³)
Solving:
W system= 18234 J
<u><em>The amount of work done on the system is 18234 J and the final positive sign means that this work corresponds to an increase in internal energy of the gas.</em></u>
<u>Answer:</u> The number of moles of weak acid is 
moles.
<u>Explanation:</u>
To calculate the moles of KOH, we use the equation:
We are given:
Volume of solution = 43.81 mL = 0.04381 L (Conversion factor: 1L = 1000 mL)
Molarity of the solution = 0.0969 moles/ L
Putting values in above equation, we get:
The chemical reaction of weak monoprotic acid and KOH follows the equation:
By Stoichiometry of the reaction:
1 mole of KOH reacts with 1 mole of weak monoprotic acid.
So, 
of KOH will react with = 
of weak monoprotic acid.
Hence, the number of moles of weak acid is moles.
Answer;
(3) Substance A is an element and substance Z is a compound.
Explanation;
-A compound is a substance formed when two or more chemical elements are chemically bonded together, such as water, carbon dioxide, methane, etc while an element is a pure chemical substance made of same type of atoms, such includes, oxygen, potassium, hydrogen, carbon, etc.
- Compounds can be broken
down or decomposed into simpler substances: elements cannot be broken down chemically into simpler substances .
Glass doesn't contain planes of atoms that can slip past each other, so there is no way to relieve stress. It has many microscopic cracks that act as seeds for fracture. It’s molecular structure is composed of tetrahedral crystals so it ruptured easily under stress
