CHEMISTRY & SOCIETY
WATER UNIT B TEST
NAME______
DATE______PERIOD______
MATCHING
1. ______Atom a) Permanent mixture that is clear throughout
2. ______Cation b) Positively charged atom or group of atoms
3. ______Control c) Temporary mixture that separates over time
4. ______Mixture d) Used to show a positive result for an experimental test
5. ______Anion e) Smallest part of an element retaining properties of that element
6. ______Reference f) Physical blend of two or more substances
7. ______Molecule g) Two or more atoms bonded together
8. ______Suspension h) Simplest form of matter from which all things are composed
9. ______Solution i) Negatively charged atom or group of atoms
10. ______Element j) Used to show a negative, or baseline, result in an experiment
SHORT ANSWER / FILL-IN
10. When light is scattered by reflecting off of small particles this is called the ______.
11. Fill out the missing information in the following table. First determine whether the given matter is a substance or mixture. Then write whether the Substance is a compound or element (if it is a substance) OR whether the mixture is Heterogeneous or Homogeneous (if it is a mixture). The first one has been done for you.
Type of Matter / Substance / MixtureSalt water / ------/ homogeneous
Milk
Carbon monoxide
Italian dressing
Lead
12. Provide 2 observations that may be made that would let you know that you had observed a CHEMICAL
CHANGE: ______, ______.
13. Tell whether each of the following is a PHYSICAL or a CHEMICAL change:
OBSERVATION / PHYSICAL or CHEMICALIce melts
Litmus paper turns red in acid
Sugar dissolves in water
Dry ice evaporates to gives off “fog”
Sodium metal reacts with water to give off a gas
14. Tell how many ATOMS of EACH element are in the following molecules:
A) H2S B) NaCl C) MgSO4 D) CaCl2
H = ______Na = _____ Mg = _____ Ca = ______
S = ______Cl = ______S = ______Cl = ______
O = ______
15. The high surface tension of water can be best illustrated by which of the following :
A) rain forms beads on your car B) Water has a high boiling point
C) Water dissolves many things D) Water is present in all three physical phases
16. We can never get completely pure water because :
A) The government is cheap B) Dissolved gasses remain in all water
C) Water is already pure D) We must save chlorine for future use
17. Which one of these would be best classified as an element?
A) Na B) Na+
C) NaCl D) More than one
18. Which one of these would be best classified as a compound?:
A) Na B) Na+
C) NaCl D) More than one
19. Which one of these would be best classified as an ion?
A) Na B) Na+
C) NaCl D) More than one
20. Provide the correct name or symbol for the elements below (NO it’s not matching):
Sodium ______K ______
Phosphorus ______Fe______
Gold ______Ca______
21. Answer the following questions given the chemical reaction below showing the formation of ammonia (NH3) :
N2 + 3H2 2NH3
a) How many nitrogen atoms are there on the left side of the arrow? ______
b) How many hydrogen atoms are there on the left side of the arrow? ______
c) How many nitrogen atoms are on the right side of the arrow? ______
d) How many hydrogen atoms on the right side of the arrow? ______
e) How many nitrogen molecules on the left side of the arrow? ______
f) How many hydrogen molecules on the left side of the arrow ______
g) How many ammonia molecules are formed on the right side of the arrow? ______
h) The small numbers written to the right of some atoms are called ______
i) The large numbers written to the left of some molecules are called ______
22. Provide two unusual properties of water, and describe the effect on life on this planet if these properties were different.
______
23. In the Water Testing Lab, you used Distilled water as a control. On NPR yesterday morning, there was a story about Nasal Irrigation. This is a process by which an otherwise sane person squirts copious amounts of saline solution up their nose to ….well….irrigate it. The people that practice this swear by the fact that it keeps them from getting sick. Devise an experiment that you could try to determine whether these claims have any merit….Include the use of a control in your experiment.
______