Question

how much heat in kilojoules is absorbed when 84.88 grams of carbon tetrachloride (ccl₄) is melted at its normal melting point? (δhfus = 3.28 kj/mole)
enter just the number. no units

Explanation:

Step1: Calculate the molar mass of \(CCl_4\)

The molar mass of \(C\) is \(12.01\space g/mol\), and the molar mass of \(Cl\) is \(35.45\space g/mol\). For \(CCl_4\), \(M = 12.01+(4\times35.45)=153.81\space g/mol\)

Step2: Calculate the number of moles of \(CCl_4\)

Using the formula \(n=\frac{m}{M}\), where \(m = 84.88\space g\) and \(M = 153.81\space g/mol\). So \(n=\frac{84.88}{153.81}\approx0.552\space mol\)

Step3: Calculate the heat absorbed

Using the formula \(q = n\times\Delta H_{fus}\), where \(n = 0.552\space mol\) and \(\Delta H_{fus}=3.28\space kJ/mol\). Then \(q=0.552\times3.28 = 1.81056\approx1.81\)

Answer:

\(1.81\)