An ideal gaseous reaction (which is a hypothetical gaseous reaction that conforms to the laws governing gas behavior) occurs at a constant pressure of 30.0 atm and releases 72.6 kJ of heat. Before the reaction, the volume of the system was 7.40 L . After the reaction, the volume of the system was 2.00 L . Calculate the total internal energy change, ΔE, in kilojoules.

What is the most common reason for matter changing its state?

Identify the branch of chemistry. percentage purity of glucose.

Yasmin's teacher asks her to make a supersaturated saline solution. her teacher tells her that the solubility of the salt is 360 g/l at room temperature (25 °c). how can yasmin make a supersaturated saline solution? she can add 380 g of salt to 1 l of hot water (75 °c) and stir until all the salt dissolves. then, she can carefully cool the solution to room temperature (25 °c). she can add 360 g of salt to 1 l of room temperature water (25 °c) and stir the solution until all the salt dissolves. she can add 380 g of salt to 1 l of cold water (5 °c) and stir the solution until most of the salt dissolves. then, she can carefully heat the solution to room temperature (25 °c). she can add 380 g of salt to 1 l of room temperature water (25 °c) and let the solution sit for 24 hours, so the salt dissolves.