Chem-assignment

CHEM-Assignment: week one 1. Do these statements describe chemical or physical properties?

(a) Oxygen gas supports combustion. Answer: ____________

(b) Fertilizers help to increase agricultural production. Answer: ____________

(c) Water boils below 100 C on top of a moun-tain. Answer: ____________

(d) Lead is denser than aluminum. Answer: ____________

(e) Uraniumis a radioactive element. Answer: ____________

2.Does each of these describe a physical change or a chemical change?

(a) The helium gas inside a balloon tends to leak out after a few hours.

Answer:________________________

(b) A flashlight beam slowly gets dimmer and finally goes out.

Answer:________________________

(c) Frozen orange juice is reconstituted by adding water to it.

Answer:________________________

(d) The growth of plants depends on the sun’s energy in a process called

photosynthesis.

Answer:________________________

(e) A spoonful of table salt dissolves in a bowl of soup.

Answer:________________________

3. Write the molecular formula of ethanol. The color codes are: black

(carbon), red (oxygen), and gray (hydrogen).

Answer:_______________________

CHEM-Assignment: week one 4. Write the formulas for these compounds:

(a) rubidium nitrite, (b) potassium sulfide, (c) perbromic acid, (d) magnesium phosphate, (e) calcium hydrogen phosphate, (f) boron trichloride, (g) iodine heptafluoride, (h) ammonium sulfate, (i) silver perchlorate, (j) iron (III) chromate, (k) calcium sulfate dihydrate.

5. Calculate the mass of 50.0 m L of ethanol (thedensity of ethanol 0.798 g/m L).

6. Mercury is the only metal that is a liquid at room temperature. Its density is 13.6 g/m L. How many grams of mercury will occupy a volume of 95.8 m L?

7. What is the periodic table, and what is its significance in the

study of chemistry? What are groups and periods in the periodic table?