Homework # 10

9)  11 grams sugar

 44 grams water

10)  150,000 ppm

11) A water molecule is polar because both negative and positive charges at opposite ends that attract one another. 

12) 

13)

a. oxygen because it is negatively charged

b. hydrogen because it is positively charged

14) Heavy metals are called "heavy" because their atoms have a much greater mass than other metals. Heavy metals can be dangerous to humans and other living creatures.

15) numbness, brain damage, tunnel vision

16)

a.

When lead entered the atmosphere through automobile exaust as lead oxide from lead being added to gasoline, humans were exposed to it.

b. Humans were exposed to mercury because mercury when mercury was used to make felt hats, the people making the hats would absorb the mercury into their skin and experience mercury posioning. 

17) Hydroxide ions 

18) Hydrogen 

19)

a. basic

b. basic

c. acidic

d. chemically neutral

20) 

a. soft drink

b. black coffee

c. milk of magnesia

21) A solution is 100 times more acidic at 2.0 compared to a 4.0

22)

Acidic: The development of fish eggs is hurt and the concentrations of metal ions in water is raised by extracting metal ions from neighboring soil

Basic: Skin and fish scales can be dossolved

Highly nasic: If animals were accidentaly exposed to items such as drain cleaner, it could damage their scales and hurt them.

23) Polar molecules have opposite charges on either end that attract one another. Nonpolar molecules have an even distribution of charge, and do not have positive and negative charges at either end. 

24) Because we already know that water and ethanol are polar substances, lamp oil would clearly be the choice becauce it is the only one left. Therefore, it must be a non polar molecule.

25) NaCl is a polar molecule. So,  it can dissolve in water which is also a polar substance. But oil is non polar. So, it doesn't mix well or dissolve in water.

26) The phrase “like dissolves like,” describes solubility behavior. Polar substances dissolve is polar solvents and non polar substances dissolve in non polar solvents because they are alike. 

27) Water and grease are composed of different molecules. Since oil is non polar, you would need a non polar moluecule to fully clean the grease off. 

33)

a. Materials that contain non polar molecules

b. These cleaners are non polar and grease is non polar, so it would be a bettter way to dissolve the grease compared to water because water is polar so it would not work very well

35) Because fluorine has the highest electronegativity, than it has the most electrons. So, flourine is negative. Because we know this, we know Hydrogen has less electrons and therefore has a positive charge.