AT&T; 3:41 PM 3:32 PM 19% Question Question Q11.55 Q11.50 Which of the following

Question

AT&T; 3:41 PM 3:32 PM 19% Question Question Q11.55 Q11.50 Which of the following statements is true about melting? Multiple Choice Determine the amount of heat required to convert 65.25 g of solid Ca at 651°C into liquid Ca at 951°C. The following information on Ca may be used to calculate the amounts of heat for each of the heating steps. melting point 851°C, boiling point 1487 C Specific Heat Capacities ssolid 0.65 J/g °C sliquid- 0.77 J/g C AHfusion-9.33 kJ/mole AHvaporization- 162 kJ/mole (Answer in kJ) During the melting process, there is no increase in temperature Numerical Answer B The solid is converting to liquid Type your response The thermal energy is being utilized to disrupt the intermolecular forces All of the above Unanswered Answered: Has been answered

Explanation / Answer

11.55

This is a three step process.

Step 1: Solid Ca at 651 oC to solid Ca at 851 oC.

Q1 = m C dT
   = (65.25 g) x (0.65 J g-1oC-1) x (851 oC - 651 oC)
   = (65.25 g) x (0.65 J g-1oC-1) x (200 oC)
   = 8482.5 J

Step 2: Solid Ca at 851 oC to liquid Ca at 851 oC to

Q2 = m dHfusion
   = (65.25 g) x (9.33 kJ mol-1)
   = (65.25 g / 40 g mol-1) x (9330 J mol-1)
   = (1.63125 mol) x (9330 J mol-1)
   = 15219.56 J

Step 3: Liquid Ca at 851 oC to liquid Ca at 951 oC.

Q3 = m C dT
   = (65.25 g) x (0.77 J g-1oC-1) x (951 oC - 851 oC)
   = (65.25 g) x (0.77 J g-1oC-1) x (100 oC)
   = 5024.25 J

Total heat = Q1 + Q2 + Q3
                   = 8482.5 J + 15219.56 J + 5024.25 J
                   = 28726.31 J
                   = 28.73 kJ

11.50

Answer is option (D) All of the above

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