Calculate the lattice enthalpy of potassium fluoride from the following data. enthalpy of formation of k(g): +89 kj · mol−1 first ionization energy of k(g): +418 kj · mol−1 enthalpy of formation of f(g): +79 kj · mol−1 electron affinity of f(g): +328 (∆h = −328) kj · mol−1 enthalpy of formation of kf(s): −567 kj · mol−1

Acentrifuge in a medical laboratory rotates at an angular speed of 3,700 rev/min. when switched off, it rotates through 54.0 revolutions before coming to rest. find the constant angular acceleration (in rad/s2) of the centrifuge. your response is within 10% of the correct value. this may be due to roundoff error, or you could have a mistake in your calculation. carry out all intermediate results to at least four-digit accuracy to minimize roundoff error. rad/s2