A student uses this apparatus to investigate the reaction between potassium hydroxide solution and dilute hydrochloric acid. polystyrene cupThis is her method.• pour 25 cm 3of potassium hydroxide solution into a polystyrene cup and record the temperature of the solution• pour 25 cm 3of dilute hydrochloric acid into a measuring cylinder and record the temperature of the acid• add the acid to the polystyrene cup and stir the mixture• record the highest temperature reached(a) (i) Give a word equation for the reaction between potassium hydroxide and hydrochloric acid. (1) ....................................................................................................................................................................................................................................................................................(ii) Explain why the student needs to stir the mixture.

(c) The student repeats the experiment on a different day, using 25 cm 3of potassium hydroxide solution and 25 cm 3of dilute hydrochloric acid.The thermometer shows the highest temperature reached at the end of the experiment. °C 25 20(i) Complete the table by giving the missing information.Give both temperatures to the nearest 0.1 °C. (2) mean temperature at start in °C temperature at end in °C temperature rise in °C5.2

(b) The table gives the temperatures of the solutions before the student mixes them. potassium hydroxide solution 17.8 °C dilute hydrochloric acid18.4 °CCalculate the mean (average) temperature of the two solutions. (2) mean temperature = .............................................................. °C(c) The student repeats the experiment on a different day, using 25 cm 3of potassium hydroxide solution and 25 cm 3of dilute hydrochloric acid.The thermometer shows the highest temperature reached at the end of the experiment. °C 25 20(i) Complete the table by giving the missing information.Give both temperatures to the nearest 0.1 °C. (2) mean temperature at start in °C temperature at end in °C temperature rise in °C5.2

A student dissolves 10.6 g of potassium hydroxide KOHin 300. g of water in a well-insulated open cup. She then observes the temperature of the water rise from 22.0 °C to 29.2 °C over the course of 6.7 minutes.Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction:→KOHs + K+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 KOH. kJmol

A student investigated how temperature affects the rate of reaction between magnesium carbonate and dilute hydrochloric acid. This is the method used.Heat hydrochloric acid to 30 oC in a conical flask.Add magnesium carbonate powder to the conical flask.Measure the loss in mass of the flask and contents every 20 seconds for 140 seconds.Repeat steps 1-3 with hydrochloric acid heated to 50 oCExplain why the contents of the conical flask lose mass.

If 0.0244mol hydrochloric acid HCl is mixed with 0.0244mol of sodium hydroxide NaOH in a "coffee cup" calorimeter, calculate the temperature change of 90.4g of the resulting solution if the specific heat of the solution is 1.00cal·g°C and the quantity of heat released by the reaction is ×1.52103cal. Round your answer to 3 significant figures.