21% of oxygen in air with barometric pressure of 625. what's partial pressure

The chemical equation for the formation of ammonia is unbalanced. 3H2 (g) + N2 (g) Right arrow. NH3 (g) If three molecules of hydrogen react with one molecule of nitrogen, how many molecules of ammonia would be formed? 1 2 3 4

Instrumental methods need only a microscopic sample to return an accurate result. Why is this so?

The experimental evidence that electrons could act as waves was based on quantized wavelengths and diffraction pattern evidence. True or False?

The (triangle) Hrxn of formation of carbon dioxide is negative. Which statement is true? The reaction is endothermic. The reaction is exothermic. The amount of carbon dioxide is more than the amount of reactants.

In the compound MgI2, how many electrons are transferred? 1 2 3 4

Something occurs when a liquid changes to a gas below its surface as well as on the surface

What happens to the reaction c2h6 + 137 kj when the temperature of the reaction is increased?

If a car is going at a speed of 36 km/hr. what is the speed in m/s

You want to create 14.0 g of copper to meld into a piece of jewelry. You know that when copper (II) chloride reacts with aluminum, copper is a product. How much aluminum would you need to start your reaction with to get 14.

What happens to electronegativity values when moving from left to right across the period in the periodic table