Concentrated Salt, hope this helps @Liatabb
The oxidation state of of Mn in Mn²⁺ = +2
the oxidation state of Mn in MnO₂ - +4
from +2 to +4 the oxidation state has increased, hence this is an oxidation reaction
eventually on both sides of the equation, both charges and masses must be balanced
lets construct this equation stepwise
Mn²⁺ ----> MnO₂
Mn atoms are balanced, however right side has O atoms, to balance the O atoms, add H₂O molecules with the coefficient to suit the number of O atoms on the right
Mn²⁺ + 2H₂O ----> MnO₂
Since there are 2 O in MnO₂, 2 H₂O molecules are added
Now to balance the H atoms, add H⁺ ions to the right side, since there are 2 H₂O molecules, add 4 protons
Mn²⁺ + 2H₂O ----> MnO₂ + 4H⁺
Next we have to balance the charges, as of now, left side has +2 net charge and right side has +4 charge. since charges of both sides should be equal, add 2 electrons to the right side, to reduce charge from +4 to +2
Mn²⁺ + 2H₂O ----> MnO₂ + 4H⁺ + 2e
Since this is a basic medium add 4 OH⁻ ions to both sides of the equation to neutralise the 4 H⁺ ions
Mn²⁺ + 2H₂O + 4OH⁻ ----> MnO₂ + 4H⁺ + 4OH⁻+ 2e
4H⁺ and 4OH⁻ neutralise to form water molecules
Mn²⁺ + 2H₂O + 4OH⁻ ----> MnO₂ + 4H₂O + 2e
since there water molecules on both sides, theres a net amount of 2 H₂O molecules on the right side, hence water is cancelled from the left side
the balanced half reaction is
Mn²⁺ + 4OH⁻ ----> MnO₂ + 2H₂O + 2e
Answer:
1) reduction
2) zero
Explanation:
Let us look at the definition of oxidation and reduction in a nutshell.
Oxidation is electron loss(oxidation number is increased)
Reduction is electron gain(oxidation number is decreased)
With the above definitions in mind let us look again at the equation in question 1:
Br2 + 2e- → 2Br-
We can see that the bromine molecule gained two electrons. Oxidation number decreased from zero on the left hand side of the reaction equation to -1 on the right hand side of the reaction equation hence the equation represents a reduction half equation.
For question 2, silver was displaced from its salt. On the left hand side of the reaction equation, silver had an oxidation number of +2. But remember than one of the riles for determining oxidation number of species is that the oxidation number of an uncombined element is zero. Hence, the oxidation number of silver element on the right hand side of the reaction equation is zero.
Answer:
D. Force of attraction between one atom and another atom
Explanation:
Chemical bond is the force of attraction between the atoms, molecules or ions due to which different types of chemical compounds are formed. Based on the types of attractions the bonds have been categorized in the following three categories-
- Ionic bonds - there is electrostatic force of attraction between the charged ions
- Covalent bonds - mutual sharing of the electrons occur
- Metallic bond - here many detached electrons are shared between more than two positively charged ions.