What does it mean for a mixture to be homogenous?
The substances are uniformly distributed; the mixture looks the same throughout (e.g. homogenized milk).
The solubility of salt in water is 357g/L. What does this mean?
The max amount of salt that can dissolve in a liter of room temperature water is 357 grams - after that, salt will start to settle on the bottom.
Why is it important NEVER to mix household cleaning products (or use different cleaning products on the same surface)?
The substances in each solution could react to form a new, dangerous substance
Name 4 different ways to separate a mixture. Provide an example where you would use one of them.
Magnetism, sifting, filtration, buoyancy, evaporation, distillation
What are the three main parts of an atom?
Protons, neutrons, electrons.
Which of these mixtures has the substances mixed the most closely (+ most stable)? Colloid, heterogenous mixture, suspension, solution, emulsion
Solution
When a gas substance is cooled, what happens to its particles? Show using words and a picture.
...
What's an exothermic reaction?
A reaction that releases energy (heat)
What's a way to increase solubility of a substance?
Heat
Explain what density is.
A ratio between mass and volume. How much mass is in a given volume. It has a relation to hardness - for example, diamond is harder than rubber because it's...
You are asked to separate a mixture of sugar and pepper. Using scientific vocab, describe how you would do it.
(dissolving, floating/settling, evaporation, etc.)
What are the 3 main types of chemical reactions? Explain what each involves.
Synthesis (combination of reactants); Decomposition (breaking down into simpler parts); Replacement (switching)
What's an endothermic reaction?
A reaction that absorbs heat (energy)
Give an example of a solid solution, liquid solution, and gas solution.
Solid: 14k gold, steel, bronze... Liquid: saltwater, sugar water, vinegar, tea, coffee, etc. Gas: air, smoke, etc.
In a solution, the substance that the solute dissolves in is called __________
the solvent
What type of reaction is involved when stuff rusts?
Synthesis (Fe + O -> FeO)
What are 3 ways to make a chemical reaction more likely to happen (or faster)?
increase temperature, surface area, pressure, concentration, stir reactants together, etc.
What happens during a replacement reaction?
Elements in compounds switch around.
When pure silver (Ag) tarnishes, it becomes Silver Sulfide (AgS). What kind of reaction do you think this is NOT? Why?
Decomposition
What does "soluble" mean? Explain with an example
Sugar can dissolve in water. It is soluble in water.
Vinegar is a solution of a very strong acid (acetic acid) and water. Which is the solute and which is the solvent?
Solvent = water; Solute = acid
Many things can dissolve in water. For that reason, water is sometimes called the universal _______.
Solvent
What is an alloy? Give an example.
A mixture (usually a solution) of a metal with another solid. e.g. brass, steel...
In a solution, the substance that dissolves in the other is called ________
The solute.