Describe the effect of each of the following on the rate of...

Name: Problem 7, Chapter 12: Chemistry
Uploaded: 2020-03-26T22:56:13-08:00
Duration: 5 min 17 s
Channel: Alexandra Woodruff
Description: Describe the effect of each of the following on the rate of the reaction of magnesium metal with a solution of hydrochloric acid: the molarity of the hydrochloric acid, the temperature of the solution, and the size of the pieces of magnesium.

Describe the effect of each of the following on the rate of the reaction of magnesium metal with a solution of hydrochloric acid: the molarity of the hydrochloric acid, the temperature of the solution, and the size of the pieces of magnesium.

Key Concepts

Reaction Rate

The reaction rate is the speed at which reactants are converted into products. It is influenced by factors such as the concentration of reactants, the temperature of the system, and the surface area of the solid reactants, all of which affect how frequently reacting particles encounter each other.

Concentration

The molarity of the hydrochloric acid represents its concentration, meaning the number of acid particles present per unit volume. A higher concentration increases the frequency of collisions with magnesium atoms, leading to an accelerated reaction rate due to more frequent effective interactions.

Temperature

Temperature plays a critical role in reaction kinetics because it determines the kinetic energy of the molecules involved. An increase in temperature results in more energetic collisions between magnesium and acid particles, thereby overcoming the activation energy barrier more easily and speeding up the reaction.

Surface Area

The size of the magnesium pieces affects the available surface area for the reaction. Smaller pieces expose more surface area relative to their volume, allowing more acid molecules to contact the magnesium simultaneously. This increased contact area leads to more collision opportunities, thus enhancing the reaction rate.

Transcript

00:01 Okay, so our question is asking us the effect of different variables on the rate of the reaction between hcl and magnesium.

00:16 And i drew three different graphs here to show the three variables that they're asking about.

00:23 The first one is the concentration of hydrochloric acid.

00:28 You can't really see it, but it's down here.

00:31 Here, the concentration of hydrochloric acid.

00:34 The second one is rate versus temperature.

00:40 And the third one they asked about is rate versus the particle size.

00:46 And so to begin, this has to do with the collision theory, which has a couple of factors.

00:56 The first being that molecules have to collide in order to react.

01:03 The second one is they have to overcome the activation energy of the reaction.

01:12 And then the third is that they have to have the right orientation in order to have a successful reaction.

01:22 And so mostly we just have to think of the first two.

01:25 The overcoming the activation energy and that they must collide.

01:32 And so if we're thinking about our first variable, which is a concentration of hydrochloric acid, if you increase the concentration of hydrochloric acid, this is increasing going this way, there's more particles in your solution.

01:53 So there's more chance for particles to collide and make a reaction.

02:00 So as your concentration of your reactant increases, also your rate increases.

02:09 So your graph would look something like this.

02:13 For the next one, let's see, we have rate versus temperature.

02:19 And so this has to do with overcoming the...

02:25 Activation energy and also more collisions because as you increase the temperature, which is increasing going this way, then you have more energy in your solution...

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