Which reaction is endothermic?

H2 (g) + ½ O2 (g) → H2O (g), ΔH = - 57.82 kcal

½N2 (g) + O2 (g) + 8.1 kcal → NO2 (g)

½N2 (g) + 3/2H2 (g) → NH3 (g) + 11.0 kcal

C (diamond) + O2 (g) → CO2, ΔH = - 94.50 kcal

Crude oil is separated into different substances such as gasoline, petroleum, diesel fuel, and propane by which process? Osmosis Chromatography Filtering Fractionation

What happens when nitrogen fills its valence shell? a. three electrons are lost, creating n 3 b. three electrons are lost, creating n-3 c. three electrons are gained, creatingn 3 d. three electrons are gained, creatingn-3

How can iodine (Z = 53) have a higher atomic number yet a lower atomic mass than telluriurn (Z = 52) ?

A voltaic cell is constructed with a Cu/Cu2 half-cell and an Ni/Ni2 half-cell. The nickel electrode is negative. Write both balanced half-reactions and the overall reaction.

Identifying How to Stay Safe during a Tornado Use the drop-down menus to complete each statement about tornado safety.

Complete and balance the molecular equation, including phases, for the reaction of aqueous ammonium bromide, nh4br, and aqueous lead (ii) acetate, pb (c2h3o2) 2.

A magnesium atom has 2 valence electrons in its third shell. Which is a TRUE statement about what happens when it forms an ion? A. It will be an anion. B. It will have more electrons than protons. C.

What scientific discoveries led to changes in Dalton's atomic theory?

What does berkelium react with

Classifying living things