Question

In: Chemistry

The density of water at room temperature is less than the assumed 1.0 g/mL used in...

The density of water at room temperature is less than the assumed 1.0 g/mL used in the calculations for determining the enthalpy of neutralization. How will this small (but real) assumption affect the reported enthalpy of neutralization for the strong acid-weak base reaction? Explain.

Solutions

Expert Solution

We make the assumption that strong acids and strong alkalis are fully ionised in solution, and that the ions behave independently of each other. For example, dilute hydrochloric acid contains hydrogen ions and chloride ions in solution. Sodium hydroxide solution consists of sodium ions and hydroxide ions in solution.

The equation for any strong acid being neutralised by a strong alkali is essentially just a reaction between hydrogen ions and hydroxide ions to make water. The other ions present (sodium and chloride, for example) are just spectator ions, taking no part in the reaction.

The full equation for the reaction between hydrochloric acid and sodium hydroxide solution is:

. . . but what is actually happening is:

If the reaction is the same in each case of a strong acid and a strong alkali, it isn't surprising that the enthalpy change is similar.


Related Solutions

0.20 g of caffeine dissolves in 10 mL of room-temperature water, while 0.66 g of caffeine...
0.20 g of caffeine dissolves in 10 mL of room-temperature water, while 0.66 g of caffeine will dissolve in 10 mL of boiling water. A. If a 5.0 g sample of caffeine is to be recrystallized from water, calculate the minimum amount of water required. B. A student uses 75.0 mL of water in order to recrystallize a 5.0 g sample of caffeine. Once cooled to room temperature, calculate the amount of caffeine remaining in the water and thus lost...
The density of a 40 wt% solution of ethanol in water is 0.937 g/mL. The density...
The density of a 40 wt% solution of ethanol in water is 0.937 g/mL. The density of n-butanol is 0.810 g/mL. What is the concentration of n-butanol in ppm if you dissolve 20 μL of this alcohol in a 40 wt% solution of Ethanol in water. The final volume of the solution is 25 mL. Assume that the density of the ethanol solution does not change upon dissolution of the butanol. Use the correct number of significant figures! Hint: to...
If we want to only use frozen water (ice) and room temperature water (room temperature water...
If we want to only use frozen water (ice) and room temperature water (room temperature water of four times the mass of the ice), write out the various forms of heat transfer that will occur between frozen water and room temperature water, when the come into contact. Hint: There will be one term of heat transfer from the room temperature water, and three terms of heat transfer in the ice/cold water.
what is the pH of: water 50.0 mL water + 1.0 mL 1.0 M HCl 50.0...
what is the pH of: water 50.0 mL water + 1.0 mL 1.0 M HCl 50.0 mL water + 1.0 mL 1.0 M NaOH 0.10 M acetic acid 0.10 M sodium acetate
A student dissolved 10.5 g of NH4Cl in 40 mL of water.  The temperature of the water...
A student dissolved 10.5 g of NH4Cl in 40 mL of water.  The temperature of the water changed from 22.5oC to 5.1oC.  Calculate the enthalpy of hydration of ammonium chloride in J/mol. 1.  A student collected the data below while performing a kinetics experiment. Trial Volume of 2.0 M Reactant A Volume of 0.5 M Reactant B Volume of H2O Time for B to react 1 10 mL 10 mL 30 mL 135 sec 2 20 mL 10 mL 20 mL 69 sec...
I was wondering, is there more or less water on the Earth than there used to...
I was wondering, is there more or less water on the Earth than there used to be a million years ago?
A solution is made by dissolving 40.0 g of KOH in 100 mL of water (density...
A solution is made by dissolving 40.0 g of KOH in 100 mL of water (density 0.995 g/mL) to form a solution. What is the mass percent solute in the solution? 1. 40.2% 2. 40.0% 3. 3.49% 4. 28.6% 5. 28.7%
1. The solubility of dulcin in water is 1.21 g/L at room temperature. Assuming that you...
1. The solubility of dulcin in water is 1.21 g/L at room temperature. Assuming that you achieved quantitative conversion (100% yield based on your measured amounts was present when you dissolved it for recrystallization) and used a total of 90.0 mL of water, what would be your maximum experimental yield after recrystallization if you had allowed the flask to cool to room temperature? Give your answer in mg. 2.One of the chemicals you added to the reaction contains potassium, but...
Boil water in a bowl and cool in a room. The air temperature in the room...
Boil water in a bowl and cool in a room. The air temperature in the room is increasing linearly according to the function Ta (t) = 22 + 0.015t (t in minutes, T in ° C). Assume that Newton's Law of Cooling is satisfied: the rate of change of water temperature is proportional to the difference between the temperature of the water and the temperature of the environment. We take the water temperature after 8 minutes and find that it...
Calculate how much energy is required to heat 20 mL of water from room temperature to...
Calculate how much energy is required to heat 20 mL of water from room temperature to 40 C & also how much energy is released when 20 mL of water is cooled from the initial temperature to 10 C
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT