Qrtr 4 final

answers like decreasing temperature and decreasing concentration would accomplish the opposite
effect- they would decrease the rate of the reaction. Basically, a lower temperature means particles
will move slower and collide less often in terms of the reaction. Likewise, a lower concentration of
reactants means that particles will collide less often and slow down the reaction. In terms of pressure,
it has a similar effect to a catalyst, just not as straightforward, so catalyst will do the job the best in
this situation.
3 For the reaction
A​ +​ ​ (aq)​
+ B​ —​ ​ (aq)​
→ AB ​ (s)
increasing the temperature increases the rate of the reaction. Which is the best explanation for this
happening?
A The pressure increases, which in turn increases the production of products.
B The concentration of reactants increases with an increase in temperature.
C The average kinetic energy increases, so the likelihood of more effective collisions between ions
increases.
D Systems are more stable at high temperatures.
Kinetic energy and heat works in this way: as the heat is increased, particles gain more energy
and move faster. As they move faster, they move at a higher rate and allow for more collisions which
quickens the reaction. This is because collisions are what conduct a reaction for the most part. When
particles of the reactants collide, they build up energy for the reaction and in turn, the product made at
the end. Anyways, this is a roundabout way to say that the more energy the particles have (from
kinetic energy/heat), the faster they move. The faster they move, the faster the reaction will proceed.
4 Which statement explains why the speed of some reactions is increased when the surface area of
one or all the reactants is increased?
A increasing surface area changes the electronegativity of the reactant particles
B increasing surface area changes the concentration of the reactant particles
C increasing surface area changes the conductivity of reactant particles
D increasing surface area enables more reactant particles to collide
Surface area is a bit difficult to explain. To explain it a bit better, if you take a piece of thick
bread, and toast it, the crust and the outer part will be nice and toasty, but you’ll have to toast it for a
really long time for the inside chewy part to get toasty. HOWEVER, when you cut up the bread into
smaller chunks and toast them, you get croutons that are toasty all the way through in a shorter
period of time. So particles behave in a similar way. A big chunk of a reactant will react slower
because the other parts of the reactant have a limited number of particles to collide with- that is just
the outside. When it is divided into smaller pieces, the reactants have more surface area to collide
with and interact with. This allows for the reaction to go faster.
catalyst