Answer:
B. materials change their properties.
Explanation:
In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.
A chemical change is one in which new kind of matter is formed.
It is always accompanied by energy changes.
- Chemical changes are not reversible.
- They lead to the production of new kinds of matter
- It involves mass changes
- Requires considerable amount of energy
pH value 1 represents a solution with the lowest OH⁻ion concentration.
<u>Explanation:</u>
pH is given by the expression as the negative logarithm to the base 10 of the concentration of hydrogen ions.
pH = -log₁₀[H⁺]
If the pH is lower than 7, pH < 7 then it is acidic
If the pH = 7, then it is neutral
If the pH > 7, then it is basic
If pH is 1 then the solution is showing mostly acidic character,which is least basic in its character.
So if the pH is 1, which is most acidic and least basic solution that is lowest OH⁻ ion concentration.
The mass of Copper deposited at the cathode : 0.296 g
<h3>Further explanation</h3>
Given
time = t = 10 min=600 s
current = i = 1.5 A
F = 96500 C
charge Cu=+2
Required
The mass of Copper
Solution
Faraday's Law
e = Ar/valence(valence Cu=2, Ar=63.5 g/mol)
Input the value :
D = g / cm³
Density = mass / volume
D = 360 g / 7.5 cm³
D = 48 g/cm³
answer D
hope this helps!
The answer to this question is 45
