So in numbers : 9n + 6 = 24
or 9n = 24 - 6
or 9n = 18
or n = 18/9
so n = 2
Given that I no not see any explanation in the previos answer, I think you can benefit of this.
Exothermic refers only to the fact that the reaction releases energy in the form of heat when occurs. So, the enthalpy is higher at start and lower and the end.
Seen in this way, you can deduct that the change in enthalpy is negative, which is what the third option says.
To solve this problem, we need to use the Pythagorean Theorem, which states that a^2 + b^2 must equal c^2. "a" is the length of one of the legs (shorter sides of the triangle) and "b" is the length of the other leg. "c" is the length of the hypotenuse.
a = y = 36.25cm
b = x = 20.93cm
a^2 + b^2 = c^2
(36.25)^2 + (20.93)^2 = c^2
1314.0625 + 438.0649 = c^2
√1752.1274 = √c^2
c = 41.8584209 ≈ 41.86
So your final answer is...
The length of the hypotenuse is about 41.86 cm.
