Calculate the ΔHf for the following reaction: 2NaCl (aq) + H2SO4 (aq) > 2HCl (aq)+ Na2SO4

Which statement about sound is not true? a. air particles travel with sound waves. b. sound waves cannot travel through a vacuum. c. sound waves exist even if no one hears them. d. air particles vibrate along the path of a sound wave.

Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution? a. 3.88 m, b. 1.03 m, c. 1.5 m, d. 15.5 m

Needthe meter is the standard unit for: 1) height 2) length 3) weight 4) mass