1.3 Mixtures of substances and Diffusion Flashcards
Chapter 1: States of Matter (34 cards)
What is diffusion?
Diffusion is the movement of particles from an area of high concentration to an area of low concentration.
Over time, the particles spread out and the concentration becomes even throughout the space.
Q: Does diffusion require energy?
Diffusion happens on its own and does not require energy. It occurs naturally as particles move from high to low concentration.
How does temperature affect the rate of diffusion?
Diffusion happens faster at higher temperatures because the particles gain more kinetic energy and move more quickly.
How does diffusion in gases compare to diffusion in liquids?
Diffusion occurs faster in gases than in liquids because gas particles are farther apart and have more kinetic energy, allowing them to spread out more quickly.
Do gases diffuse at the same rate at the same temperature?
At the same temperature, gases do not diffuse at the same rate.
Lighter gases (with smaller molecules) diffuse faster than heavier gases (with larger molecules).
Why do gases diffuse at different rates at the same temperature?
At the same temperature, gases diffuse at different rates because of the difference in molecular masses.
Lighter particles travel faster, so they diffuse faster than heavier particles.
How can the difference in diffusion rates of gases be demonstrated?
It can be demonstrated in the reaction between ammonia (NH₃) and hydrogen chloride (HCl) gases inside a glass tube.
The NH₃ (lighter gas) will diffuse faster and react with HCl to form ammonium chloride (NH₄Cl), creating a visible white ring closer to the HCl end of the tube.
How does the reaction between ammonia (NH₃) and hydrogen chloride (HCl) demonstrate the difference in diffusion rates?
When ammonia (NH₃) and hydrogen chloride (HCl) gases are introduced in a glass tube, they react to form ammonium chloride (NH₄Cl), which appears as white smoke.
The white smoke forms closer to the HCl end of the tube because ammonia (MR = 17), being a lighter gas, diffuses faster than hydrogen chloride (MR = 36.5), so they meet before reaching the middle of the tube.
What is soluble?
If a substance dissolves in a solvent, it is said to be soluble.
What is a mixture?
two or more substances mixed together
but not chemically combined - the substances
can be separated by physical means
What is solution?
is formed when a substance (solute)
dissolves into another substance (solvent)
What is solvent?
solvent: the liquid that dissolves the solid solute
to form a solution; water is the most common
solvent but liquids in organic chemistry that can
act as solvents are called organic solvents
What is suspension?
a mixture containing small particles of an insoluble solid, or droplets of an insoluble liquid, spread (suspended) throughout a liquid
What is precipitation reaction?
a reaction in which an
insoluble salt is prepared from solutions of two
soluble salts
What is insoluble?
If a substance does not dissolve in a solvent, it is said to be insoluble.
What is miscible?
If two liquids form a completely uniform
mixture when added together, they are said to
be miscible
What are alloys?
Alloys are mixtures of elements (usually metals)
designed to have the properties useful for a
particular purpose, e.g. solder (an alloy of tin and
lead) has a low melting point
What is saturated solution?
A solution that contains
as much dissolved solute as possible at a particular temperature
What is concentration?
Concentration is a measure of how much solute is dissolved in a given amount of solvent or solution.
Solutions can be dilute (with a high proportion of
solvent), or concentrated (with a high proportion
of solute)
What is solubility?
A measure of how much of a solute dissolves in a solvent at a particular temperature
What is the most commonly used solvent?
or
What is called the universal solvent?
Water
What are organic solvents used for?
Organic solvents are important when we need to dissolve materials that don’t dissolve in water, making them essential in chemistry labs, cleaning products, and manufacturing.
What are organic solvents?
Most solvents other than water are organic liquids. This means they are made from carbon-based compounds. Examples include: Ethanol, Propanone, Trichloroethane
Give an example of a mixture of solids.
sand and salt, Alloys like brass (copper and zinc)
