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32 Cards in this Set
- Front
- Back
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Why are some molecules polar and some are not? |
Water is an example of a polar molecule since it has a slight positive charge on one side and a slight negative charge on the other. The dipoles do not cancel out resulting in a net dipole. Due to the polar nature of the water molecule itself, polar molecules are generally able to dissolve in water. |
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How dose water dissolve some ionic compounds? |
Ionic compounds dissolve in water because the water molecules hydrate the ions. |
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How dose polarity affect the behavior of water? |
Water has a partial negative charge on one side of the molecule and a partial positive charge on the other. When two water molecules are nearby, their complimentary positive and negative charges form a hydrogen bond. |
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What is the differences between a mixture and a pure substance? |
Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components. |
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What makes one mixture? |
A combination of two or more substance that are not chemically two or more substances are mixtures. |
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Why is a compound or an element a pure substance? |
A compound is a pure substance composed of two or more different atoms chemically bonded to one another.
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What dose a fixed proportion mean? |
states that a chemical compound always contains exactly the same proportion of elements by mass. |
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What is a heterogenous. Give an example. |
A heterogeneous mixture is simply any mixture that is not uniform in composition – it’s a non-uniform mixture of smaller constituent parts. Using various means, the parts in the mixture can be separated from one another
Example: * Pizza is a heterogeneous mixture because they can be separated by dough, sauce, cheese, and other toppings. |
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What is a homogenous mixture? Give an example. |
A homogeneous mixture is simply any mixture that is uniform in composition throughout.
Example: A cup of coffee is considered a homogeneous mixture. if the sugar is completely dissolved, the coffee is still considered homogeneous, since the mixture of coffee and sugar is uniform throughout the cup. |
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What is a solution? Give an example and why it is a solution. |
A liquid homogenous mixture,transparent, cannot be filtered.
Example: Some examples of solutions are salt water, rubbing alcohol, and sugar dissolved in water. When you look closely, upon mixing salt with water, you can't see the salt particles anymore, making this a homogeneous mixture. |
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What is a suspension? |
A heterogenous mixture that separates over time. |
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What is a colloid? GIve an example and why it is a colloid. |
A colloid contains some particles that are intermediate in size between the small particles in a solution and the larger particles in a suspension.
Example: (Milk) it is a colloid because Tiny particles of milk fat are suspended in the watery liquid and don't settle out. (Milk is white that is strong evidence it is a colloid.) |
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What is a solute? |
A solute is the thing that gets dissolved in a solution.
Example: * Sugar in Kool Aid.* Sugar in maple syrup. * Carbon dioxide (the bubbles) in soft drinks. * Acetic acid in vinegar |
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What is a solution? |
A liquid homogeneous mixture, transparent, cannot be filtered. |
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What is a concentration? |
The relative amount of a given substance contained within a solution or in a particular volume of space; the amount of solute per unit volume of solution. |
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How can you separate a mixture? |
The substances in a mixture are separated by the differences in their physical properties, such as their particle size. |
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What is filtration? |
A process that separate materials based on the size of their particles. |
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How dose filtration work? |
By forcing a liquid with particles suspended in it through a membrane that has holes large enough for the liquid to pass through. |
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What is distillation? Give an example. |
The action of purifying a liquid by a process of heating and cooling. |
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How dose distillation work? Give an example. |
* Salt water
When you boil the salt water the salts are left behind. When the water vapor condenses again, into pure water. |
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What would I use to get the salt out of saltwater? |
I would use distillation |
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What is solubility? |
A property of the solute ( solid, liquid, or gas) to dissolve in a solvent. |
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What is a supersaturated solution? |
Supersaturation is a state of a solution that contains more of the dissolved material than could be dissolved by the solvent under normal circumstances. |
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What is a saturated solution? |
A solution in which the maximum amount of solvent has been dissolved |
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What is a unsaturated solution? |
An unsaturated solution is one where there are less particles or solutes than solvent in the solution. |
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What is density? |
Is mass per unit volume how heavy something is compared to its size. |
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What is malleability? |
The ability of a solid to be hammered without shattering. Most metals are malleable. |
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What is viscosity? |
The tendency of a liquid to keep flowing or it's resistance to flowing. |
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What are the tree main evidences of of a chemical change? |
* A color change * Production of a gas * Formation of a substance |
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How are are physical and chemical changes different? |
A physical change in a substance doesn't change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed. |
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What is the law of conservation of mass |
The law of conservation of mass states thats mass is neither created nor chemical in a chemical reaction. |
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What s the difference between heterogenous and homogenous mixtures? |
The difference between heterogeneous and homogeneous mixtures is the degree at which the materials are mixed together and the uniformity of their composition. |
