Substance a is a base, and substance b is an acid
C. a plane for forming a scientific hypotheses
The average speed is 75 Km per hour. Remember the equation for speed is Speed = Distance divided by Time
There are several information's already given in the question. Based on those information's the answer can be easily determined.
M = <span>1.11 g CH4
C = </span>4.319 kJ g C⋅°
∆T = 35.65 - 24.85 degree centigrade
= 10.8 degree centigrade.
Then
∆H =−M ⋅ C ⋅∆T
= - 1.11 * 4.319 * 10.8
= - 51.776 kJ/<span>mol
I hope the procedure is clear enough for you to understand.</span>