Use the following information on cr to determine the amounts of heat for the three heating steps required to convert 126.3 g of solid cr at 1760°c into liquid cr at 2060°c. mp = 1860°c bp = 2672°c enter in kj. useful data: \delta hδ hfus = 20.5 kj/mol; \delta hδ hvap = 339 kj/mol; c(solid) 44.8 j/g°c; c(liquid) = 0.94 j/g°c

Answer : The amount of heat required is, 639.3 KJ

Solution :

The conversions involved in this process are :

Now we have to calculate the enthalpy change.

where,

= enthalpy change or heat required = ?

m = mass of Cr = 126.3 g

= specific heat of solid Cr =

= specific heat of liquid Cr =

n = number of moles of Cr =

= enthalpy change for fusion = 20.5 KJ/mole = 20500 J/mole

Now put all the given values in the above expression, we get

    (1 KJ = 1000 J)

Therefore, the amount of heat required is, 639.3 KJ

explanation:

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here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.

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