A) NaOH(s) > NaOH(aq)
B) NaOH(s) + HCl(aq) > NaCl(aq) + H2O(l)
C) NaOH(aq) + HCl(aq) > NaCl(aq) + H2O(l)
Examine the 3 reaction equations, and determine the relationship between them. Demonstrate this relationship by combining the equations in a manner consistent with Hess' Law.
Write the net ionic equation for the reactions above, and then combine them in a manner consistent with Hess' Law.
So I was able to do the second equation, but I was confused o what it meant by combining them in a manner consistent with Hess' Law. This is in both questions and I have no idea what this means.
Reverse equation 1 and add to equation 2 and that gives equation 3.
In chemistry, Hess's Law states that the heat change in a chemical reaction is independent of the route taken. In other words, the enthalpy change of a reaction can be calculated by considering the enthalpy changes of a series of other reactions that can be combined to give the desired reaction.
To determine the relationship between the given equations A, B, and C, let's examine them step-by-step:
A) NaOH(s) > NaOH(aq)
This equation represents the dissolution of solid sodium hydroxide (NaOH) into aqueous sodium hydroxide.
B) NaOH(s) + HCl(aq) > NaCl(aq) + H2O(l)
This equation represents the reaction between solid sodium hydroxide and aqueous hydrochloric acid (HCl) to form aqueous sodium chloride (NaCl) and liquid water (H2O).
C) NaOH(aq) + HCl(aq) > NaCl(aq) + H2O(l)
This equation represents the reaction between aqueous sodium hydroxide and aqueous hydrochloric acid to form aqueous sodium chloride and liquid water.
Now, let's write the net ionic equations for these reactions:
A) NaOH(s) > Na+(aq) + OH-(aq)
This net ionic equation shows the dissociation of solid sodium hydroxide into sodium ions (Na+) and hydroxide ions (OH-).
B) Na+(aq) + OH-(aq) + H+(aq) + Cl-(aq) > Na+(aq) + Cl-(aq) + H2O(l)
This net ionic equation shows the reaction between aqueous sodium hydroxide and hydrochloric acid to form aqueous sodium chloride and liquid water.
C) Na+(aq) + OH-(aq) + H+(aq) + Cl-(aq) > Na+(aq) + Cl-(aq) + H2O(l)
This net ionic equation is the same as in equation B, representing the reaction between aqueous sodium hydroxide and hydrochloric acid to form aqueous sodium chloride and liquid water.
To combine these equations using Hess's Law, we need to cancel out the common species in the three equations. In this case, we see that the sodium ions (Na+) and chloride ions (Cl-) appear on both sides of the equations and can be canceled out.
The combined equation using Hess's Law would be:
NaOH(s) > NaOH(aq)
NaOH(aq) + HCl(aq) > NaCl(aq) + H2O(l)
This combined equation represents the overall reaction of solid sodium hydroxide dissolving in water, forming aqueous sodium hydroxide, and reacting with hydrochloric acid to form aqueous sodium chloride and water.
Hess' Law is a principle in chemistry that states that the overall heat change in a chemical reaction is independent of the pathway taken. In other words, if you can express a reaction as a combination of multiple steps, the total enthalpy change for the reaction is equal to the sum of the enthalpy changes for each step.
To demonstrate the relationship between the given equations using Hess' Law, we need to manipulate the equations so that the desired reaction (C) can be obtained by combining the other two reactions (A and B), and still maintain the stoichiometry.
Equation A represents the dissolution of solid NaOH in water, which results in an aqueous NaOH solution. Equation B represents the reaction of solid NaOH with aqueous HCl, resulting in the formation of NaCl (sodium chloride) and water.
To combine the equations using Hess' Law, we need to reverse equation A and multiply equation B by an appropriate coefficient to balance the number of moles of NaOH in both equations. The balanced chemical equations will be as follows:
A) NaOH(aq) > NaOH(s) (reversed)
B) 2NaOH(s) + 2HCl(aq) > 2NaCl(aq) + 2H2O(l) (multiplied by 2)
Now we can sum up the two equations:
A + 2B: NaOH(aq) + 2HCl(aq) > NaOH(s) + 2NaCl(aq) + 2H2O(l)
This is the net ionic equation for the reactions above. It demonstrates the relationship between the three reactions by combining them in a manner consistent with Hess' Law.
By using Hess' Law, we can see that equation C is derived from combining equation A with equation B.