Question

if 75.4 j of energy is absorbed by 0.25 mol of ccl4 at constant pressure, what is the change in temperature? the specific heat of ccl4 is 0.861 j/g°c

Explanation:

Step1: Calculate the mass of \(CCl_4\)

The molar mass of \(CCl_4\) is \(M=(12 + 4\times35.5)\space g/mol=154\space g/mol\).
Given \(n = 0.25\space mol\), using \(m=n\times M\), we have \(m=0.25\space mol\times154\space g/mol = 38.5\space g\).

Step2: Use the heat - mass - specific heat - temperature change formula

The formula for heat \(Q = mc\Delta T\), where \(Q = 75.4\space J\), \(m = 38.5\space g\), \(c=0.861\space J/g^{\circ}C\).
We need to solve for \(\Delta T\), so \(\Delta T=\frac{Q}{mc}\).
Substitute the values: \(\Delta T=\frac{75.4\space J}{38.5\space g\times0.861\space J/g^{\circ}C}\).
First, calculate \(38.5\times0.861 = 33.1485\).
Then \(\Delta T=\frac{75.4}{33.1485}\approx2.3^{\circ}C\).

Answer:

C. \(2.3^{\circ}C\)