Answer:
part a=A. A physical change, then a chemical change
part b:evidence
without physical change any sorts of chemical change do not take place.
for example: when sugar is heated on spoon the physical change takes place in sugar .sugar starts to form liquid from solid.
The dissociation of cadmium chloride is as follows: CdCl₂(s) → Cd⁺²(aq) + 2Cl⁻(aq)
<h3>What is dissociation?</h3>
Dissociation is the process by which a compound body breaks up into simpler constituents; said particularly of the action of heat on gaseous or volatile substances.
It is a chemical reaction in which a compound breaks apart into two or more components. The general formula for a dissociation reaction follows the form:
AB → A + B
According to this question, cadmium chloride undergoes dissociation into cadmium and chlorine ions as follows:
CdCl₂(s) → Cd⁺²(aq) + 2Cl⁻(aq)
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Answer:
2.1 moles of water formed.
Explanation:
Given data:
Moles of water formed = ?
Moles of Ni(OH) = 4.20 mol
Solution:
Chemical equation:
2Ni(OH) → Ni₂O + H₂O
Now we will compare the moles of Ni(OH) with water.
Ni(OH) : H₂O
2 : 1
4.20 : 1/2×4.20 = 2.1 mol
2.1 moles of water formed.
Explanation:
An acid is a substance that produces excess hydroxonium ions in solution.
An acid based on the pH scale is a substance that has a low pH. Acid lies within a range of 1-7 on the pH scale.
- A pH of 7 is for neutral compounds like water.
- A pH greater that 7 is for basic compounds.
- In order to raise the pH, we are driving at a substance becoming more neutral or basic.
This can be achieved by adding more base to the solution of the substance. When we add more base, hydroxyl ions will neutralize the excess hydroxonium ions and drag the pH towards that of neutrality.
Addition of more base can eventually make the substance basic.
learn more:
Phosphoric acid brainly.com/question/11062486
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Elements are ordered from left to right, increasing atomic number as they go. The periodic table allows us to find out and predict things about elements that haven’t been discovered yet!