Question

Need help with #6 please!

ultur iettl:Mgo(s) HCI(aq) ither absorbed or released for all chemical reactions, and we call this energy the enthalpy of 3 Enersy is . If the enthalpy of reaction is positive, then we say that the energy was absorbed or that eactin was endothermic. It the enthalpy of reaction is negative, then we say that energy was releascd reactio ction was exothermic. Most chemical reactions are exothermic. In this problem, you will or that the ount of heat released when solid MgO is reacted with aqueous HCİ to forma water and then ou will calculate the heat of reaction. MgO(s) + 2HCl(aa)-H2O)+MgCl(aq) Start Virtual ChemLab, select the list of assignm Thermodynamics, and then select Heat of Reaction ents. The lab will open in the Calorimetry laboratory. MgO-Hchets a bottle of MgO near the balance. A weigh paper will be on the balance with There will be approximately 2.81 g Mgo on the paper. Record the mass of Mgo of 2. in the data table. The empty calorimeter will be on the lab bench and there will also be a beaker filled with 100 mL of 1.000 M HCI. Drag the beaker to the calorimeter until it snaps into place and pour the HCl into the calorimeter. Make certain the stirrer is On (you should be able to see the shaft rotating). Click the Lab Rook to open it. In the thermometer window click Save to begin recording data. Allow 20-30 seconds to obtain a baseline temperature of the HCl solution. Drag the weigh paper containing the MgO mple over to the calorimeter and drop the sample in. Observe the change in temperature until it reaches a maximum and then emperature window. (You can click on the clock on the wall labeled Accelerate to accelerate the time in the laboratory.) A data link record data for an additional 20-30 seconds. Click Stop in the icon will appear in the lab book. Click the data link icon and record the temperature before adding the MgO and the highest temperature after adding the Mgo in the data mber that the water will begin to cool down after reaching the equilibrium tempera table. (Reme ture.) Data Table MgO/HC Mass M initial temperature (C) 24 final temperature (C) ature (C)4 4. Is the observed reaction endothermic or exothermic?What will be the sign of AHrm 5. Calculate the change in temperature, AT. Record your results in the results table on the following 21.35 AT 4.34 24 Calculate the mass of the reaction mixture in the calorimeter. (To do this, assume that the density of the HCl solution originally in the calorimeter can be approximated with the density of water (1.0 g/mL). Record your results in the results table. page 6.

Answer 1

Q6. volume of HCl = 100 mL

density of HCl = density of water = 1.0 g/mL

mass of HCl = (volume of HCl) * (density of HCl)

mass of HCl = (100 mL) * (1.0 g/mL)

mass of HCl = 100 g

mass of MgO = 2.81 g

mass of reaction mixture = (mass of HCl) * (mass of MgO)

mass of reaction mixture = (100 g) * (2.81 g)

mass of reaction mixture = 102.81 g