Properties
This property of water allows a pin to float on the surface of water.
What is surface tension?
Why does propane C3H8 mix poorly with water
Propane is made up of C and H so propane is nonpolar and will not have areas of + and - charge.
Why are nonpolar substances less dense in general?
Density equals mass/volume. Since nonpolar molecules are spaced farther apart, they occupy more volume. More volume results in lower density.
Give more than one reason why water experiences particularly strong hydrogen bonding.
The O-H bond has a greater degree of partial + and partial - charge and water has 2 O-H bonds.
This property of water demonstrates the attraction of one water molecule to another.
What is cohesion?
Which types of elements make up salts?
Metals and nonmetals.
Why doesn't the stability change much when nonpolar substances are mixed together?
Nonpolar substances do not have areas of + and - charge, which means they will not attract each other much.
In the specific heat capacity lab, why was the metal immersed for around 20 minutes in the boiling water bath?
In order to ensure that the metal reaches thermal equilibrium with the boiling water.
This property of water allows water to attach to other surfaces?
What is adhesion?
Why is salt able to dissolve in water?
The metals in salts have + charges and nonmetals have - charges which attract the + and - areas in water.
Why does KCl mix poorly with oil.
K is a metal (metals are in columns 1-13) and Cl is a nonmetal (nonmetals are in columns 14-18). When metals and nonmetals pair together, metals tend to have + charges and nonmetals tend to have - charges. The strong attractive force between K and Cl makes it a solid at room temperature. Oil has no areas of + and - charge and will be unable to separate K from Cl.
The temperature of a substance doesn't depend on the quantity of the substance. However heat does. Why?
The greater the mass, the more energy which can be trapped by the substance.
Water molecules tend to "stick" together because of positively and negatively charged "ends" of the molecule. So, we say it is what kind of molecule?
What is a polar molecule?
Which element wants to gain electrons more - F or N and why?
F because it is closer to the noble gas neon than N is.
Many larger nonpolar molecules are liquids instead of gases. Compare the boiling point of nonpolar substances to that of polar substances.
Boiling involves the change of phase from liquid to gas. It requires energy for something to boil because the molecules in the liquid state must be pushed farther apart. Since nonpolar molecules are farther apart in general, then nonpolar substances require less energy to boil. The boiling point of nonpolar liquids are lower in general.
Why does hot water take such a long time to drop in temperature?
Water has a particularly high specific heat capacity, so when the water reaches a high temperature, this means that considerable energy was trapped by the water. If a lot of energy was absorbed, more energy must be released to see an noticeable drop in temperature.
Calculate the heat gained by water if the specific heat capacity is 4.18 J/gC, and the sample size is 150 mL, and the starting temperature is 21 C and the maximum temperature reached is 24 C.
1881 J
How can you break the surface tension of water?
By adding a nonpolar substance such as oil. Oil is less dense than water so it will form a layer above the water. Also, the nonpolar molecules are not attracted to each other because they do not have areas of + and - charges so a surface "skin" is unable to form.
Algae is increasingly being used to make biofuel, an oily substance. In order to remove oil from the algae, what can be done?
Remove the oil, by using mixing the algae with a nonpolar substance such as hexane C6H14. It will form a layer separate from the polar layer.
Why did the different brass samples have different values for the specific heat capacities.
Brass is made up of the two metals copper and zinc. Copper and zinc each have different specific heat capacities and not all the brass samples have the same percentages of copper and zinc.