Part IV - Pennies

- Turn hot plate on to “3”

- use steel wool to “clean up” pennies

- use your forceps to place pennies into the “silver pot”

Putting It Together – COM Review

Which of the following is a compound?(a) lead (c) potassium(b) wood (d) water

Which of the following is a mixture?(a) water (c) wood(b) chromium (d) sulfur

How many atoms are represented in the formula Na2CrO4?

(a) 3 (b) 5 (c) 7 (d) 8

(d) water

(c) wood

(c) 7

Which of the following is a characteristic of nonmetals?

(a) always a gas (b) poor conductor of electricity (c) shiny (d) combines only with metals

Which of the following is a characteristic of metals?

(a) ductile (b) easily shattered (c) extremely strong (d) dull

(a) ductile

(b) poor conductor of electricity

Chromium, fluorine, and magnesium have the symbols

(a) Ch, F, Ma (c) Cr, F, Mg (b) Cr, Fl, Mg (d) Cr, F, Ma

When a pure substance was analyzed, it was found to contain carbon and chlorine. This substance must be classified as

(a) an element (b) a mixture (c) a compound (d) both a mixture and a compound

Coffee is an example of (a) an element(b) a compound(c) a homogeneous mixture(d) a heterogeneous mixture

Sodium, carbon, and sulfur have the symbols

(a) Na, C, S (c) Na, Ca, Su (b) So, C, Su (d) So, Ca, Su

The number of oxygen atoms in Al(C2H3O2)3

is(a) 2 (b) 3 (c) 5 (d) 6

Which of the following is a mixture?(a) water (c) sugar solution (b) iron(II) oxide (d) iodine

Which is the most compact state of matter?(a) solid (c) gas(b) liquid (d) amorphous

Part IV – continued

- Turn hot plate down to “1”

- use your forceps to flip pennies over

- take your seat

Which is not characteristic of a solution?a) a homogenous mixtureb) a heterogeneous mixturec) contains 2 or more substancesd) has a variable composition

A chemical formula is a combination ofa) symbols b) atoms c) elements d) compounds

The number of nonmetal atoms in Al2(SO3)3 is a) 5 b) 7 c) 12 d) 14

Which of the following is not a physical change?a) boiling point b) physical state c) bleaching action d) color

Which of the following is a physical change?a) A piece of sulfur is burnedb) A firecracker explodesc) A rubber band is stretchedd) A nail rustsWhich of the following is a chemical change?a) Water evaporates b) Ice

meltsc) Rocks are ground to sand d) a penny tarnishes

When 9.44g of calcium are heated in air, 13.22g of calcium oxide are formed. The percent by mass of oxygen in the compound isa) 28.6% b) 40.0% c) 71.4% d)13.2%BaI2 contains 35.1% barium by mass. An 8.50g sample of BaI2

contains what mass of iodine?a) 5.52g b) 2.98g c) 3.51g d) 6.49g

HgS contains 86.2% mercury by mass. The mass of HgS that can be made from 30.0g of mercury isa) 2586g b) 2.87g c) 25.9g d) 34.8gThe changing of liquid water to ice is known as a a) chemical change b) heterogeneous changec) homogeneous changed) physical change

Which of the following does not represent a chemical change?a) Heating of copper in airb) Combustion of gasolinec) Cooling of red-hot irond) Digestion of food

Changing hydrogen and oxygen into water is a a) Physical changeb) Chemical changec) Conservation reactiond) No correct answer given

Part IV – continued

- Turn off the hot plate

- Light & adjust bunsen burner - “see” the interior blue cone

- “hear” it

- use your forceps to remove pennies, rinse in beaker, pat dry

- use your forceps to heat pennies over hottest part of flame

– watch for transition & cool in beaker