The correct sign on the heat of solution + neutralisation of NaOH is
Question
The correct sign on the heat of solution + neutralisation of NaOH is
Solution
The heat of solution and neutralisation of NaOH is an exothermic process. This means that heat is released during the process. Therefore, the correct sign on the heat of solution + neutralisation of NaOH is negative (-).
Here are the steps to understand why:
-
Dissolving NaOH in water is an exothermic process, meaning it releases heat. This is because the bonds being formed in the solution (between the Na+, OH- ions and water molecules) are stronger than the bonds being broken (within the NaOH and the water). Therefore, more energy is released than is absorbed.
-
The neutralisation of NaOH (a base) with an acid is also an exothermic process. In a neutralisation reaction, an acid reacts with a base to form water and a salt, releasing heat in the process.
-
In both these processes, heat is released, not absorbed. Therefore, the sign on the heat of solution + neutralisation of NaOH is negative (-), according to the sign convention in thermodynamics where exothermic reactions are assigned a negative heat value.
Similar Questions
Another student in the class repeated this experiment. The student's calculated values for ΔH1 and ΔH2 are shown below. ΔH1 PART B1 (heat of neutralisation of NaOH) = -42.54 kJ mol-1ΔH2 PART B2 (heat of solution + neutralisation of NaOH) = -120.42 kJ mol-1Use these values to determine this students experimentally determined answer for the enthalpy of solution for NaOH (ΔH3) in kJ mol-1.Provide your answer to 1 decimal place. INCLUDE A SIGN. Do not include units.
When standard solution of NaOH is left in air for few hours
A student dissolves 11.6 g of sodium hydroxide NaOHin 300. g of water in a well-insulated open cup. He then observes the temperature of the water rise from 23.0 °C to 33.9 °C over the course of 6.1 minutes.Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction:→NaOHs + Na+aq OH−aqYou can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to the correct number of significant digits.Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction.Is this reaction exothermic, endothermic, or neither? exothermicendothermicneitherIf you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case. kJCalculate the reaction enthalpy ΔHrxn per mole of NaOH. kJmol
The mass of 70%H2SO4 required for neutralization of 1mol of NaOH .
Input your answer for the enthalpy of solution of NaOH (ΔH3) here. Your answer should be in kJ mol-1 to 2 decimal places. INCLUDE A SIGN. Do not include units.
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.