Write the net ionic equation for this reaction occurring in water: ammonium fluoride and magnesium chloride are mixed to form magnesium fluoride and ammonium chloride. 1. no reaction occurs. 2. 2 nh+ 4 + 2 cl− → 2 nh4cl 3. 2 f− + mg2+ → mgf2 4. 2 nh4f + 2 cl− → 2 f− + 2 nh4cl 5. 2 f− + mgcl2 → mgf2 + 2 cl−

Harvey kept a balloon with a volume of 348 milliliters at 25.0˚c inside a freezer for a night.  when he took it out, its new volume was 322 milliliters, but its pressure was the same.  if the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer? the temperature of the freezer is  kelvins.

Ajet plane is speeding down the runway during takeoff. air resistance is not negligible. identify the forces on the jet.

There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. in the first step, calcium carbide and water react to form acetylene and calcium hydroxide: cac2 (s) + 2h2o (g) → c2h2 (g) + caoh2 (s) =δh−414.kj in the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6c2h2 (g) + 3co2 (g) + 4h2o (g) → 5ch2chco2h (g) =δh132.kj calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. round your answer to the nearest kj .