A large piece of iron was reacted with an acid. What would happen to the rate of the reaction had the large piece been finely divided into smaller pieces?

It will decrease because the reactant particles are moved farther apart.
It will increase because the reactant particles are brought closer together.
It will decrease because larger particles provide more surface area to react.
It will increase because smaller particles provide more surface area to react.

When 225mg of anthracene, c14h10(s), was burned in a bomb calorimeter the temperature rose by 1.75k. calculate the calorimeter constant. by how much will the temperature rise when 125mg of phenol, c6h5oh(s), is burned in the calorimeter under the same conditions? (δch< (c14h10,s)=–7061 kj mol−1.)

What does the symbol (–hfus) indicate in a phase change?

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?