Question

Express your answer as a chemical equation. Identify all of the phases in your answer.

a)2AuCl3(aq)+3Sn(s)→3SnCl2(aq)+2Au(s)

b)2NaI(aq)+Br2(l)→2NaBr(aq)+I2(s)

c)2AgNO3(aq)+Sn(s)→Sn(NO3)2(aq)+2Ag(s)

Please show work with legible explanation, identifying all of the phases in your answer.

The questions is in the work that I do not know how to do it and that is why I requested to show the work, because I don't only want the answer I want to see the work so I can understand what this exercise is asking of me.
1 - The exercise asks me to identify all of the phases in my answer, what does that mean? - I do not know.  
2 - When I express my answer in chemical equation is that the same as writing the net ionic equations for the reactions? Or is that something different?
3 - I am so lost between that and defining and differentiating what is a precipitation versus and acid-base neutralization versus a redox reaction. Could you please clarify?

Answer 1

Q1. To identify the phases means what is the phase of reactants and products. The most commonly used phases are : Solid (s) , Liquid (l) , Gaseous (g) , aqueous (aq)

For example, when we write the equation : 2 AuCl₃ (aq) + 3 Sn (s) 3 SnCl₂ (aq) + 2 Au (s)

This means AuCl₃ is in aqueous phase (or dissolved in water), Sn is in solid phase, SnCl₂ is in aqueous phase and Au is in solid phase

Q2. When asked for writing the chemical equation, you write the molecular equation. If the question specifically asks to write net ionic equation then only write net ionic equation.

For example : Molecular / chemical equation : 2 AuCl₃ (aq) + 3 Sn (s) 3 SnCl₂ (aq) + 2 Au (s)

Net ionic equation : 2 Au³⁺ (aq) + 3 Sn (s) 3 Sn²⁺ (aq) + 2 Au (s)

Q3. In precipitation reaction, formation of precipitate occurs as a reaction between two or more reactants. This is generally double displacement reactions.

For Example: AgNO₃ (aq) + NaCl (aq) AgCl (s) + NaNO₃ (aq)

Here AgCl is in the solid phase after reaction which means AgCl is precipitated

In acid - base neutaralisation reaction, formation of water molecules is the key indicator that the reaction is an acid - base neutralisation reaction

For Example : HCl (aq) + NaOH (aq) NaCl (aq) + H₂O (l)

In redox reaction , oxidation state of reactants change

For Example : C (s) + O₂ (g) CO₂ (g)

Here oxidation state of carbon changes from zero in C (s) to +4 in CO₂ . Since oxidation state of carbon increases from 0 to +4 , therefore carbon is said to be oxidized

Oxidation state of oxigen changes from zero in O₂ (g) to -2 in CO₂ (g) . Since oxidation state of oxygen decreases from 0 to -2, therefore oxygen is said to be reduced