PS02 and PS03 TEST - Water and Solutions

Solid, liquid and gas are the three ________ of water on our planet.
1. colors
2. chemical compositions
3. formulas
4. states
Water changes into vapor or evaporates at 100ºC and the reverse, or ________ at 100ºC.
1. melts
2. condenses
3. freezes
4. flows
When water ________ it turns into ice.
1. evaporates
2. condenses
3. freezes
4. melts
When ice ________ , it turns into liquid.
1. melts
2. freezes
3. evaporates
4. condenses
The attraction of water molecules to each other forms a “skin” on the surface due to the ________ ________ forces.
1. surface tension
2. skin elastic
3. surface repulsion
4. surface solution
What doesn't a liquid need to be contained?
1. side
2. top
3. inside
4. bottom
Why does ice float?
1. less dense than water
2. same density as water
3. ice sinks
4. more dense than water
Why is water known as the “Universal Solvent”?
1. We needed a name for it.
2. molecules are always made up of two words.
3. So few things are dissolved in it.
4. So many things are dissolved in it.
Salt in water is a solution. Salt is the _________ there is more water than salt.
1. mixture
2. soluter
3. solvent
4. solute
Liquids take the shape of their ________ and need only sides and a bottom.
1. lid
2. container
3. top
4. solid
Ice, made from water, ________ in water because it is less dense than liquid water.
1. floats
2. sinks
3. sinks to the bottom
4. turns red
Slight electrical forces between water molecules make them ________ to other water molecules.
1. shift to the bottom
2. float
3. repelled
4. attracted
When one thing is dissolved into another a ________ is formed.
1. solution
2. solte
3. solute
4. solvent
Salt __________ the melting point of ice.
1. raises
2. neither raises nor lowers
3. lowers
4. doubles
What two things happen to water at 100º C?
1. evaporation and condensation
2. melting and freezing
3. boiling and freezing
4. boiling and melting
We either add heat energy or remove heat energy to change the ________ of water and ice.
1. color
2. state
3. coolness
4. direction
Water molecules are polar because the atoms make one side a bit electrically positive and another side the north pole.
1. true
2. false
This happens when atoms break free of chemical bonds and recombine to form new substances.
1. endothermic reactions
2. color shifts
3. chemical reactions
4. exothermic reactions
These typically have one, two or three letters with the first one capitalized.
1. chemical thermics
2. chemical symbols
3. chemical drawings
4. chemical colors
Chemical reactions can be ___________ by counting the numbers of atoms on the reactant side and the product side of a balanced equation.
1. colored
2. predicted
3. estimated
4. divided
This happens when chemicals break their bonds and recombine to form new compounds.
1. reaction
2. replacement
3. fixture
4. exothermic
Which is NOT a way to show a chemical reaction?
1. picture or drawing
2. chemical shorthand or symbol
3. color or taste
4. word equation
Matter can neither be created nor destroyed. This is the law of _________ of mass.
1. destruction
2. conservation
3. distortion
4. changing
The number of atoms in the reactants is __________ the number of atoms in the products.
1. half
2. equal
3. twice
4. 3.982 times
A subscript tell how many electrons are in a molecule.
1. true
2. false
A coefficient tells how many molecules are in a reaction.
1. true
2. false
Exothermic means that the reaction gives off heat.
1. true
2. false
Endothermic means that the reaction gives off heat.
1. true
2. false
Endothermic means that the reaction gives off cold
1. true
2. false
Hydrogen and oxygen combine to form water.
1. true
2. false
in a chemical reaction, the ____________ of atoms remains the same.
1. polarity
2. color
3. exothermic
4. number
The terms exo and endo describe the heat of a reaction.
1. true
2. false

PS02 and PS03 TEST - Water and Solutions

Select the best answer.