Plsss helppp How many moles of nitrogen gas would be produced if 7.63 moles of copper ( ) oxide were reacted with excess ammonia in the following chemical reaction ? 2 NH 3 (g)+3 CuO(s) 3Cu(s)+N 2 (g)+3H 2 O(g)

How are evaporation and sublimation similar? a both involve the formation of a gas. b both release energy to the surroundings. c both take place throughout a solid. d both take place at the surface of a liquid.

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?