Answer:
The pH is 9,21.
Explanation:
The pH indicates the acidity or basicity of a substance. PH values between 0 and less than 7 indicate acidic solutions, 7 neutral and higher than 7 to 14 basic. It is calculated as
pH = -log (H 30+)
pH= -log (6,2 x 10^-10)
<em>pH=9,21</em>
There is no chemical change
BY CHECKING THE REACTIVITY OF AN ELEMENT WHICH IS MOST REACTIVE OR NOT AND YOU STUDY TYPE OF CHEMICAL REACTION IN 1 CH AND YOU CHECK THE REACTIVITY OF ELEMENTS IN 3 CH METALS AND NON METALS PAGE NO 45 IN NCERT BOOK
Answer: Physical change : tearing of paper, fixing of wtaer
Chemical change: rusting of iron , electrolysis of water, Rancidification
Explanation:
Physical change is a change in which there is no rearrangement of atoms and thus no new substance is formed. There is only change in physical state of the substance.
Example: tearing of paper, fixing of wtaer
Chemical change is a change in which there is rearrangement of atoms and thus new substance is formed. There may or may not be a change in physical state.
Example: rusting of iron , electrolysis of water, Rancidification
