Nacl has a hfus = 30.2 kj/mol. what is the mass of a sample of nacl that needs 732.6 kj of heat to melt completely? 24.3 g 82.7 g 1,407.1 g 1,417.7 g

Answer : The mass of the sample of NaCl will be, 1417.7 grams.

Explanation : Given,

This means that,

As, 1 mole of sample of NaCl has an enthalpy of fusion = 30.2 kJ

And, 1 mole of NaCl has the mass = 58.44 grams

As, 30.2 kJ of heat is needed for a mass 58.44 grams of NaCl

So, 732.6 kJ of heat will be needed for = grams of NaCl.

Hence, the mass of sample of NaCl will be, 1417.7 grams.

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm