List four possible clues to a chemical change

Is pain reliever a prescription drug?

Use Hess's Law or the summation equation to calculate the ΔHrxn. Round to the nearest tenth! ___NF (g) + ___F2 (g) - -> ___NF2 (g) ½N2 (g) + ½F2 (g) - > NF (g) Hf = 86.6 kJ ½N2 (g) + F2 (g) - > NF2 (g) Hf = 33.8 kJ

When a molecule absorbs IR electromagnetic energy, what are the vibrational modes affected

You have a solution that contains 1.0 g of oxalic acid dissolved in 100 mL of ether. This solution is placed in a separatory funnel, and then washed with 100 mL of water. Diethyl ether and water are immiscible solvents.

Which option describes a common property of the elements, nitrogen (N), phosphorus (P), arsenic (As) ? Hint: Review your periodic table. They have the same amount of reactivity. They have the same amount of atomic mass.

A student Increases the temperature of a 417 cubic centimeter balloon from 278 K to 231 K. Assuming constant pressure what should the new volume of the balloon be

What is the molarity of a solution with 1.17 moles of Ca (OH) 2 disolved in 0.2 liters of water? A. 1.17 M B. 0.2 M C. 0.17 M D. 5.85 M

What happens to acetone molecules when you add heat to a beaker of liquid acetone?

An effluent discharge with a flow of 1.5 m3/s and an ammonium-N concentration of 2 mg/L is released to a river with a flow of 12 m3/s and an ammonium-N concentration of 0.015 mg/L.

If you were to pour 4 different liquids into a glass and the liquids separated into 4 layers, which liquid would have the highest density?