Chemistry S1.1.2 | Free Chemistry Video | RevisionDojo
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Chemistry S1.1.2
Learn Chemistry S1.1.2 in this free IB Chemistry video lesson for S1.1.2 The Kinetic Molecular Theory.
About this video
Learn Chemistry S1.1.2 in this free IB Chemistry video lesson for S1.1.2 The Kinetic Molecular Theory.
Summary of the Video
The video explores Structure 1.1.2, focusing on the Kinetic Molecular Theory (KMT) and the properties of solids, liquids, and gases. It explains that all substances are made of particles in constant motion, with elastic collisions and kinetic energy proportional to temperature. The arrangement and behavior of particles in solids, liquids, and gases are compared, highlighting their ability to flow, compressibility, shape, and volume.
Key changes of state are discussed, including:
Melting (s→l)
Evaporation/Boiling (l→g)
Condensation (g)
00:00In this video we look
00:01at structure 1 .1 .2
00:04which includes a quick look
00:05at the kinetic molecular theory
00:07of solids, liquids and gases.
00:09We look at the states
00:10of matter, we look at
00:12the use of state symbols
00:13and also the changes of
00:15state. So we'll start by
00:18looking at the particle models
00:19of a solid liquid and
00:20gas. So from left to
00:22right we have a solid
00:23
→
l
Freezing (l→s)
Sublimation (s→g)
Deposition (g→s)
The video also introduces state symbols used in chemical reactions and physical processes:
(s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous solutions. Examples include reactions like sodium with chlorine and methane with oxygen, as well as physical processes like melting and sublimation.
in the middle we have
00:25our liquid and on the
00:27right we
00:28have our gas. So according
00:31to the Kinetic Molecular Theory
00:33or the KMT, all substances
00:35are made up of particles.
00:38These particles are in constant
00:40straight line motion. They have
00:42elastic collisions, which means there's
00:44no loss in kinetic energy
00:46when two particles collide. And
00:48the absolute temperature of the
00:50substances is directly proportional to
00:52the kinetic energy of the
00:54particles.
00:56So for a solid, the
00:57particles are all closely packed
00:59together. For liquid, the particles
01:01are still quite close together,
01:03but there's a little bit
01:04of space which shows the
01:06particles are able to move.
01:08And in a gas, we
01:09can see that there's a
01:10lot more space between the
01:11particles. So next we look
01:14at some properties which other
01:15flow can they be compressed,
01:17their shape and their volume.
01:19So solids cannot flow, they
01:21cannot be compressed, they have
01:23a fixed shape,
01:24and a fixed volume. Liquids
01:27can flow but cannot be
01:29compressed. They don't have a
01:31fixed shape instead they take
01:32the same shape as the
01:34bottom of the container that
01:35they're in. But they do
01:37have a fixed volume. Gases
01:39can flow and can be
01:41compressed. They don't have a
01:44fixed shape instead they take
01:45the same shape as the
01:46shape of the container that
01:48they're in, and they don't
01:49have a fixed volume.
01:52Next we look at the
01:53changes of state which are
01:54melting, evaporation and boiling, condensation,
01:58freezing, sublimation, and deposition. So
02:03let's start with melting which
02:04is a change of state
02:05from solid to liquid, s
02:08to l. Then we have
02:09evaporation and boiling which is
02:11the change of state from
02:12liquid to a gas or
02:14from l to g. Even
02:16though both are for the
02:18change of state from liquid
02:19to gas, they are not
02:20the
02:20same. Boiling tends to occur
02:22at a specific point, which
02:24is termed the boiling point
02:25of a substance. And evaporation
02:28can occur at lower temperatures
02:29than boiling. Next we have
02:32condensation, which is gas to
02:34liquid or G to L.
02:37And then we have freezing,
02:38which is liquid to solid
02:39or L to S. So
02:42these are the changes of
02:43state that we are fairly
02:44familiar with in our everyday
02:45lives, which leaves two changes
02:48of state
02:48which are not so common,
02:50sublimation and deposition. Sublimation is
02:54the change of state from
02:55a solid directly to a
02:57gas, so from s to
02:58g with no liquid state.
03:08And deposition is the change
03:10of state from gas directly
03:11to a solid, again with
03:14no liquid state.
03:16Although these changes of state
03:23are less common, you do
03:24need to be familiar with
03:26those, so make sure you
03:27remember to include sublimation and
03:29deposition when learning your changes
03:31of state. So next we
03:35look at state symbols. So
03:36state symbols represent the state
03:39that a reactant or product
03:41is in in a chemical
03:43reaction.
03:44So the state symbols we'll
03:47use are S, which is
03:49for solid, L, which is
03:51for liquid, G, which is
03:54for gas, and then A,
03:56Q, which is for substance
03:58in an aqueous solution. So
04:02here we have an example,
04:03chemical reaction in which sodium
04:05reacts with chlorine to form
04:07sodium chloride. In terms of
04:10state symbols, we have an
04:11S for sodium,
04:13from G for chlorine and
04:15an S for sodium chloride.
04:18This means that the sodium
04:20is a solid, the chlorine
04:21is a gas, and the
04:23sodium chloride is a solid.
04:26In the next example, we
04:28have the reaction between methane
04:29and oxygen to produce carbon
04:31dioxide and water. So in
04:33terms of state symbols, we
04:35have G for methane, which
04:36is a gas, the same
04:37for oxygen, the same for
04:39carbon dioxide, and then we
04:41have L for water, which
04:42is a liquid. And the
04:44last example, we have the
04:46reaction between lithium and water
04:47to produce lithium hydroxide and
04:49hydrant gas. So we have
04:51S for lithium, which is
04:53a solid. We have L
04:55for water, which is a
04:55liquid. We have AQ for
04:58lithium hydroxide, which means that
05:00it is dissolved in solution.
05:02So it's an aqueous solution.
05:04And then we have G
05:05for hydrogen, which means it's
05:07a gas. So this
05:09chemical reaction has all four
05:11state symbols. We can also
05:13use state symbols to represent
05:15physical processes. For example, here
05:18we have H20S, which is
05:20solid water or ice, and
05:22that's forming liquid water, and
05:25this process is known as
05:26melting. Another example is the
05:29sublimation of iodine, where iodine
05:31as a solid changes directly
05:34to iodine as a gas.
05:36So here we have the
05:37state symbols changing from S
05:39directly to G. So state
05:43symbols can be used in
05:44both chemical reactions and also
05:47they can be used to
05:47represent physical changes such as
05:50melting or sublimation.
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