Choose whether the reaction is exothermic or endothermic 2C(s) + 2H2(g) → C2H4(9) --Select--
2H2(g) + O2(g) → 2H20() --Select--
N2(g) + 3H2(g) → 2NH3(9) --Select--

In what environment would mineral formation caused by high pressures and high temperatures most likely occur?

Cryolite, na3alf6(s), an ore used in the production of aluminum, can be synthesized using aluminum oxide. start this question by first balance the chemical equation.1.) balance the equation: - alo3(s)+naoh(l)+hf(> na3alf6+h2o(g). 2.) if 17.5 kilograms of al2o3(s), 51.4 kilograms of naoh(l), and 51.4 kilograms of hf(g) react completely, how many kilograms of cryolite will be produced? 3.)which reactants will be in excess, (al2o3, naoh, or hf) 4.)what is the total mass of the excess reactants left over after the reaction is complete in kg?

Concentrations expressed as a percent by mass are useful when the solute is a a. liquid b. gas c. solid