Which equation is commonly used to calculate the change in thermal energy (q) of a substance during a temperature change?

• A. q = m riangle H
• B. q = m c riangle T
• C. q = n R T
• D. q = P riangle V

Answer: (B)

Verified step by step guidance

1. Understand that the problem asks for the equation used to calculate the change in thermal energy (q) when a substance undergoes a temperature change.
2. Recall that thermal energy change depends on the mass of the substance (m), the specific heat capacity (c), and the temperature change (\triangle T).
3. Identify the correct formula for thermal energy change as: \(q = m \times c \times \triangle T\) where \(q\) is heat energy, \(m\) is mass, \(c\) is specific heat capacity, and \(\triangle T\) is the temperature change.
4. Recognize that the other options correspond to different concepts: \(q = m \triangle H\) relates to enthalpy changes, \(q = nRT\) is related to ideal gas law, and \(q = P \triangle V\) relates to work done by gas expansion or compression.
5. Conclude that the equation \(q = m c \triangle T\) is the commonly used formula to calculate the change in thermal energy during a temperature change.