When is a reaction with a positive enthalpy spontaneous?

Explain why pure hydrogen cyanide does not conduct electricity, but become a conductor when it is dissolved in water? (at room temp, pure hcn exists as a volatile liquid)

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?

The ozone molecule o3 has a permanent dipole moment of 1.8×10−30 cm. although the molecule is very slightly bent-which is why it has a dipole moment-it can be modeled as a uniform rod of length 2.5×10−10 m with the dipole moment perpendicular to the axis of the rod. suppose an ozone molecule is in a 8000 n/c uniform electric field. in equilibrium, the dipole moment is aligned with the electric field. but if the molecule is rotated by a small angle and released, it will oscillate back and forth in simple harmonic motion.what is the frequency f of oscillation?