When copper metal is added to nitric acid, the following reaction takes place Cu (s) + 4 HNO₃ (aq) → Cu(NO₃)₂ (aq) + 2 H₂O (l) + 2 NO₂ (g)
Calculate the volume in liters of NO₂ gas collected over water at 25.0 °C when 2.97 g of copper is added to excess nitric acid if the total pressure is 726.0 mmHg. The vapor pressure of water at 25.0 °C is 23.8 mm Hg.

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?