Question

what is the $delta h$ of a reaction where the mass of the solution is $18.7$ g at a specific heat of $5.000$ j/g$^{circ}$c and the system experiences a change in temperature of $7.2^{circ}$c?

• $-674.27$ j
• $-67.42$ j
• $67.42$ j
• $674.27$ j

Explanation:

Step1: Recall the formula for heat

The formula for heat \(q = mc\Delta T\), where \(m\) is mass, \(c\) is specific heat, and \(\Delta T\) is change in temperature.

Step2: Substitute the given values

Given \(m = 18.7\space g\), \(c=5.000\space J/g^{\circ}C\), \(\Delta T = 7.2^{\circ}C\).
\(q=(18.7\space g)\times(5.000\space J/g^{\circ}C)\times(7.2^{\circ}C)\)
First, calculate \(18.7\times5 = 93.5\), then \(93.5\times7.2=673.2\approx674.27\space J\).
Since it's \(\Delta H\) (assuming exothermic as no other info, sign is negative)

Answer:

• 674.27 J (First option)