Which of the following equations can be used to determine the change in enthalpy of a system?

What is the name of region in Africa where human fossils are found

How will a positive and a negative charge react to each other

Scenario: You are testing two different household solutions with your cabbage indicator, using the color key to the right. The second solution turns purple. A possible hydrogen ion concentration for this solution is: A. 1 * 10-2 M B. 7 * 10-3 M C.

How much salt (in grams) must be added to a two liter bottle of pure water to make the resulting mixture 0.035 percent salt by weight

A 2.40 L volume of air has a pressure of 101.7 kPa. If initially the pressure of the air was 101.01 kPa, what was the initial volume of air? Assume all other properties remain constant.

Sarah heated some orange coloured crystals in a test tube. The crystals turned green and fizzed. After the fizzing stopped, the test tube was allowed to cool. A green powder was left in the tube.

In which orbital does an electron in a bromine atom experience the greatest effective nuclear charge?

Kool-Aid is made up of sugar (C6H12O6), food coloring, and water. It is an example of a (n) element heterogeneous mixture homogeneous mixture compound

A laboratory experiment requires 250 millimeters of water for boiling. It also requires 100 millimeters of water for a cooling process.

Which set of procedures and observations indicates a chemical change? A) Ethanol is added to an empty beaker and the ethanol eventually disappears. B) A solid is gently heated in a crucible and the solid slowly turns to liquid.