Chemistry 12/8 – Flashcards

Activation energy is the energy given off when reactants collide an energy barrier between reactants and products the heat released in a reaction generally very high for a reaction that takes place rapidly

Why does a higher temperature cause a reaction to go faster? there are more collisions per second only collisions occur with greater energy only there are more collisions per second or the collidions are of greater energy there are more collisions per second and the collisions are of greater energy

Why does a higher concentration make a reaction faster? There are more collisions per second and the collisions are of greater energy There are more collisions per second or the collisions are of greater energy Collisions occur with greater energy only There are more collisions per second only

Why does a catalyst cause a reaction to proceed faster? The activation energy is lowered only There are more collisions per second and the collisions are of greater energy There are more collisions per second only The activation energy is lowered

What happens to a catalyst in a reaction? It evaporates away It is incorporated into the products It is unchanged It is incorporated into the reactants

The rate of a chemical reaction normally is slowed down by a catalyst decreases as reactant concentration increases decreases as temperature increases increases as reactant concentration increases

Which of the following substances act as a catalyst in the body? nucleic acids lipids enzymes carbohydrates

At equilibrium, what is the rate of production of reactants compared with the rate of production of products? lower the same higher much higher

If sulfur dioxide and oxygen can be made into suffer trioxide, what is the reverse reaction? SO2 + 2SO3 -- 3S + 4O2 2SO3 -- 2SO2 +O2 SO3 + O2 -- SO5 2SO2 + O2 -- 2SO3

Consider the reaction N2 + 3H2 -- 2NH3. What is the effect of decreasing the volume on the contained gases? The pressure on the gases decreases momentarily Ammonia is consumed in the reaction The system reacts by increasing the number of gas molecules The reaction shifts toward the product gas

What happens to a reaction at equilibrium when more reactant is added to the system? The reaction is unchanged The answer cannot be determined The reaction makes more products The reaction makes more reactants

In an endothermic reaction at equilibrium when more reactant is added to the system? The reaction is unchanged The answer cannot be determined The reaction makes more products The reaction makes more reactants

In a reaction (at equilibrium) that makes more moles of gas than it consumes, what is the effect of increasing the pressure? The reaction is unchanged The answer cannot be determined The reaction makes more products The reaction makes more reactants

Which of the changes listed below would shift the following reaction to the right? 4HCl + O2 -- 2Cl2 + 2H2O increase of pressure addition of Cl2 decrease of pressure removal of O2

What is the effect of adding more water to the following equilibrium reaction? CO2 + H2O -- H2CO3 There is no effect More H2CO3 is produced CO2 concentration increases The equilibrium is pushed in the direction of the reactants