I can't fully answer this question because it is incomplete. In order for me to help you, I could just define what a precipitation reaction is and give a concrete example.
A precipitation reaction consists of two aqueous solutions that when reacted together, forms an insoluble salt. For example,
AgNO₃ (aq) + HCl (aq) --> AgCl (s) + HNO₃ (aq)
In this case, the precipitate is AgCl, Silver Chloride, which appears as a white solid.
Answer:

Explanation:
Hello!
In this case, given this is an acid-base neutralization and we are considering a diprotic acid, we can write the following mole-mole relationship:

It means that the moles of acid can be computed given the volume and concentration of NaOH:

It means that the approximate molar mass of the acid is:

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<h2>Frequency</h2>
Explanation:
Wave frequency is the number of waves that pass a fixed point in a given amount of time.
Wave speed is the speed at which a wave travels.
Let the wave speed be 
Let the wave frequency be 
Let the wave length be 
The wave speed,frequency and wave length are related by the equation
.
When
increases,
increases on the other side to maintain equality when no other property is changing.
Order.
Hope this helps! :)
The balanced chemical reaction for the complete combustion of C4H10 is shown below:
C4H10 + (3/2)O2 --> 4CO2 + 5H2O
The enthalpy of formation are listed below:
C4H10: -2876.9 kJ/mol
O2: none (because it is pure substance)
CO2: -393.5 kJ/mol
H2O: -285.8 kJ/mol
The enthalpy of combustion is computed by subtracting the total enthalpy formation of the reactants from that of the products.
ΔHc = (4)(-393.5 kJ/mol) + (5)(-285.8 kJ/mol) - (-2876.9 kJ/mol)
= -<em>126.1 kJ</em>
Thus, the enthalpy of combustion of the carbon is -126.1 kJ.