Physical Change: It is a type of change in which matter changes its physical state like shape, size but is not transformed into another substance. It is usually a reversible process.
Chemical Change: It is a type of change in which the rearrangement of atoms of one or more than one substance is involved. and it changes its chemical composition that is there is a formation of at least one new substance. It is usually an irreversible process.
Now, keeping in mind the definitions, we can easily classify the examples in the question as physical or chemical change.
7. Chemical Change
8. Chemical Change
9. Physical Change
10. Chemical Change
11. Physical Change
12. Physical Change
13. Chemical Change
14. Physical Change
15. Chemical Change
16. Physical Change
17. Chemical Change
18. Chemical Change
19. Physical Change
20. Physical Change
21. Chemical Change
22. Physical Change
23. Chemical Change
24. Chemical Change
25. Physical Change
Answer:
Molar absorptivity or molar extinction co-effecient = 2120.14 cm⁻¹M⁻¹
Explanation:
First convert Concentration from ppm inM or mol/l
⇒ Molar mass of KMnO₄ = 158.03 g
⇒ 4.48 ppm = 4.48 mg/l = 4.48 x 10⁻³ g/l
⇒ Molarity = 
= 2.83 x 10⁻⁵ molar
Absorbance (A) = - log(T) ( T = % transmittance)
= - log(0.859)
= 0.06
According to Lambert Beer's law
ε = 
or, ε = 
or, ε = 2120.14 cm⁻¹M⁻¹
Where
ε = Molar absorptivity
A = absorbance
C = Molar concentration of KMnO₄ solution
l = length
The vapors of some chemicals used in the chemistry laboratory, especially isocyanates, can react and bond the contact lens to the eye.
(FYI - the family of isocyanates include Superglue..I wouldn't want to have been the person who discovered this unfortunate reaction!)
Answer:
The Order is as follow,
C-H < S-H < H-Br < H-Cl
Explanation:
Polarity depends on the electronegativity difference between two atoms, greater the electronegativity difference, greater will be the polarity of bond and vice versa.
Electronegativity Difference between Hydrogen and other given elements are as follow,
1) C-H;
E.N of Carbon = 2.55
E.N of Hydrogen = 2.20
------------
Difference 0.35
2) S-H;
E.N of Sulfur = 2.58
E.N of Hydrogen = 2.20
------------
Difference 0.38
3) H-Br;
E.N of Bromine = 2.96
E.N of Hydrogen = 2.20
-------------
Difference 0.76
4) H-Cl;
E.N of Chlorine = 3.16
E.N of Hydrogen = 2.20
-----------
Difference 0.96
Hence it is proved that the greatest electronegativity difference is found between H and Chlorine in H-Cl, therefore it is highly polar bond and vice versa.
No. The only thing that changed was the looks of the gasoline, not the chemical components.
