Question

the heat of fusion of nacl(s) is 0.48 kj/g. how much heat is absorbed when 20.0 g of nacl(s) at its melting point melts completely?
a 0.024 kj
b 9.6 kj
c 28 kj
d 42 kj

Explanation:

Step1: Identify the formula

The formula for heat absorbed \(q = m\times\Delta H_{fus}\), where \(m\) is the mass and \(\Delta H_{fus}\) is the heat of fusion.

Step2: Substitute the values

Given \(m = 20.0\space g\) and \(\Delta H_{fus}=0.48\space kJ/g\).
\(q=(20.0\space g)\times(0.48\space kJ/g)\)

Step3: Calculate the result

\(q = 20\times0.48\space kJ=9.6\space kJ\)

Answer:

B. \(9.6\space kJ\)