Elements are a one of a class of substances that cannot be seperwted into simpler substances by chemicalk means.
Compounds is a substance formed when two or more chemical elements are chemically bonded together.
Relation: When two elements or more are formed chemically together its called a compound without elements there won't be compounds and without compounds there won't be elements.
Given:
Concentration of Fluoride ions = 0.100 M
Concentration of Hydrogen Fluoride = 0.126 M
Asked: Concentration of fluoride ions after the addition of 5ml of 0.0100 M HCl to 25 mL of the solution
Assume: 50:50 ratio of fluoride ions and HF
12.5ml*0.1mol/L *1L/1000mL + 12.5*0.126mol/L * 1L/1000mL = 2.825x10^-3 moles F-
5ml * 0.01 mol/L *1L/1000mL = 5x10^-5 moles
Assume: Volume additive
Final concentration = 2.825x10^-3 + 5x10^-5 moles/ 30 ml * 1000ml/L =0.0958 M
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Answer:
The volume of the gas sample at standard pressure is <u>819.5ml</u>
Explanation:
Solution Given:
let volume be V and temperature be T and pressure be P.



1 torr= 1 mmhg
42.2 torr=42.2 mmhg
so,


Now
firstly we need to find the pressure due to gas along by subtracting the vapor pressure of water.

=735-42.2=692.8 mmhg
Now
By using combined gas law equation:



Here
are standard pressure and temperature respectively.
we have

Substituting value, we get


Answer:
Ionic bonds hold charged particles in solid NaCl together, such that they are unable to move or conduct electricity.
Explanation:
Consider an electric current that flows through a conductor: charge moves in a uniform direction from one end of the conductor towards the other.
Thus, there are two conditions for a substance to conduct electricity:
- The substance shall contain charged particles, and
- These charged particles shall be free to move across the substance.
A conductor of electricity shall meet both requirements.
Now, consider the structure of solid NaCl
. NaCl is an ionic compound. It contains an ocean of oppositely charged ions:
- Positive
ions, and - Negative
ions.
Ions carry charge. Thus, solid NaCl contains charged particles and satisfies the first condition.
Inside solid NaCl
, electrostatic attractions ("ionic bonds") between the oppositely charged ions hold these ions in rigid ionic lattices. These ions are unable to move relative to each other. As a result, they cannot flow through the solid to conduct electricity. Under solid state, NaCl is unable to satisfy the second condition.
As a side note, melting NaCl into a liquid breaks the ionic bonds and free the ions from the lattice. Liquid NaCl is a conductor of electricity.