Answer : The balanced reduction half-reaction is:
Explanation :
Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.
Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.
Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.
The given balanced redox reaction is :
The half oxidation-reduction reactions are:
Oxidation reaction : 
Reduction reaction : 
In order to balance the electrons, we multiply the oxidation reaction by 2 and reduction reaction by 3 and then added both equation, we get the balanced redox reaction.
Oxidation reaction : 
Reduction reaction :
The balanced redox reaction will be:
Thus, the balanced reduction half-reaction is:
Answer:
It does not always retain the properties of the substances that make it up
It requires heat energy to make
Explanation:
A compound is a chemical substance composed of two or more kinds of atoms or elements joined together in a definite grouping.
The properties of compounds are distinct from those of individual elements that are combined in its make up.
- To produce a compound, a chemical change must take place
- As with most chemical changes, heat is required to drive the change.
- So, to form compounds, some amount of heat is needed to cause the change.
Watershed
A watershed is an entire river system of an area drained by a river and its tributaries
Answer:
a. single replacement
Explanation:
Chemical equation:
Cd + H₂SO₄ → CdSO₄ + H₂
In given reaction Cd replace the hydrogen and form cadmium sulfate and hydrogen gas.
Single replacement:
It is the reaction in which one elements replace the other element in compound.
AB + C → AC + B
Other options are incorrect because,
Combustion:
In combustion reaction substances are burn in the presence of oxygen and form carbon dioxide and water.
Synthesis reaction:
It is the reaction in which two or more simple substance react to give one or more complex product.
A + B → AB
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AC +BD
Balanced half-reactions:
Anode: Fe2+ -> Fe
Cathode: Mg2+ -> Mg
The cell is voltaic because the cathode has a more negative reduction potential, causing the cell potential to be positive.
The electrons flow from the anode to the cathode.
