Solutions Review OL Chem

An insect like a water strider can skate along the top of a pond because:

• water has a high specific heat

• water has high surface tension

• water has low surface tension

• when water freezes, it becomes less dense, causing ice to float

Why does ice float?

• As water freezes, it expands and its density decreases.

• As water freezes, it takes up more hydrogen from the atmosphere, causing it to have a greater buoyancy.

• As water freezes, air becomes trapped between the water molecules.

• As water freezes, it takes up more oxygen from the atmosphere, causing it to have a greater buoyancy.

A molecule with electrically charged areas is called a _______________.

• magnet
• polar molecule
• solution
• electrical molecule

Tags

NGSS.MS-PS1-1

Which end of the water molecule has a slightly positive charge?

• the oxygen end
• the hydrogen end
• both ends are slightly positive
• neither end is positive

Water is a universal solvent because it...

• It can be found anywhere

• It freezes when it gets cold

• floats when frozen

• Dissolves a lot of substances

Ice floats when placed in a liquid water because:

• ice is less dense than the liquid
• ice is more dense than the liquid
• ice is soluble
• water is adhesive

Which of the following is LEAST likely to dissolve in water?

• nonpolar fats and oils
• polar sugar molecules
• salt made of a positive sodium ion and a negative chloride ion
• all of the substances will dissolve easily in water

Tags

NGSS.HS-PS1-1

Which statement best describes an effect of the low density of frozen water in a lake?

• When water freezes, it contracts, decreasing the water level in a lake.
• Water in a lake freezes from the bottom up, killing most aquatic organisms. 
• When water in a lake freezes, it floats, providing insulation for organisms below.
•  Water removes thermal energy from the land around a lake, causing the lake to freeze.

Tags

NGSS.HS-ESS2-5

Water is very resistant to changing temperature. This is because it has

• High density

• Low density

• High specific heat

• Low specific heat

Tags

NGSS.HS-ESS2-5

The substance being dissolved in a solution.

• is always a gas

• is called the solute

• is called the solvent

• is always a solid