The rust that appears on steel surfaces is iron(III) oxide. If the rust found spread over the surfaces of a steel car body contains a total of 1.188×1023 oxygen atoms, how many grams of rust are present on the car body?

The following questions a24 - a26 relate to 100 ml of 0.0150 m solution of benzoic acid (c6h3cooh). ka(c6h3cooh) = 6.4 x 10^-5. what is the ph of the solution after the addition of 1 x 10^-3 moles of naoh? you may assume no volume change to the solution upon addition of the naoh.