CP Chemistry Toxins Unit 1 Practice Problems - key

Review: Counting Atoms (using subscripts and coefficients)

Identify the type of atom and the quantity of the atom in each of the following formulas:

  1. C8H9NO2 (acetaminophen in Tylenol)

8 carbon atoms, 9 hydrogen atoms, 1 nitrogen atom, 2 oxygen atoms

  1. Zn(C2H3O2)2 (dietary supplement to obtain zinc)

1 zinc atom, 4 carbon atoms, 6 hydrogen atoms, 4 oxygen atoms (2 acetate groups)

  1. 2 MgCl2

2 magnesium atoms, 4 chlorine atoms

  1. 5 Ca (NO3)2

5 calcium atoms, 10 nitrogen atoms, 30 oxygen atoms (10 nitrate groups)

Review: Writing Chemical Formulas (Ionic)

  1. Write the correct IONIC formula for compounds formed between the following:
  1. Na+1 and O-2Na2O
  2. B3+ and N3-BN
  3. Al3+ and S-2Al2S3
  4. Rb+1 and P-3Rb3P
  5. Ca2+ and (PO4)-3Ca3 (PO4)2
  1. Write the correct IONIC formula for compounds that form between the following:
  1. ION of Potassium and ION of BromineKBr
  2. ION of Gallium and ION of ArsenicGaAs
  3. ION of Cesium and ION of FluorineCsF
  4. ION of Berylium and the polyatomic ION HydroxideBe(OH)2

Balancing Equations & Types of Reactions

1.Balance each of the following equations:

The Odd-Even technique:

  1. _4__Fe + _3__O2 _2__Fe2O3
  2. _2__ H2O2 __2_H2O + __1_O2
  3. _2__C8H18 + _25__ O2 _16__ CO2 + __18_H2O

Polyatomics as a Group:

  1. __1_ Zn + __1_ Pb(NO3)2 __1_ Pb + __1_ Zn (NO3)2
  2. __1_H2C2O4 + __2_ NaOH _1__ Na2C2O4 + _2__ H2O
  3. __2_ Al + __3_ CuSO4 _1__Al2 (SO4)3 + _3__Cu

Mixed Problems:

  1. _1__K2SO4 + __1_BaCl2 _1__ BaSO4 + _2__ KCl
  2. __1_Fe2O3 + __3_CO __1_Fe + __3_ CO2
  3. _2__ K + _2__H2O __2_KOH + __1_H2
  4. __1_Si3N4 __3_Si + _2_ N2
  5. _3__Mg + __2_H3PO4 _1__Mg3(PO4)2 + _3__H2
  6. __1_C2H5OH + __3_O2 _2__CO2 + _3__H2O

2. Types of Reactions: Balance and Identify the type of reaction.

  1. __4_Fe (s) + __3_ O2 (g) __2_Fe2O3 (s) synthesis/combination/addition
  2. __1_Mg(s) + __2_AgNO3 (aq) _1__Mg(NO3)2(aq) + _2_Ag (s)

single replacement/displacement/exchange

  1. _1__CuCO3(s) _1__CuO (s) + _1__ CO2 (g)decomposition
  2. _1__NaOH (aq) + _1_HCl(aq) __1_NaCl (aq) + __1_H2O (l)

double replacement/displacement/exchange

  1. __2_C6H6 (l) + _15__O2(g) __12_ CO2 (g) + _6__H2O (l)

combustion

3. Predict the products for each of the sets of reactants in the problems below AND balance each equation AND identify the type of reaction.

Reaction Type

  1. __Mg(s ) + ___Na2SO42Na + MgSO4single replacement
  1. __Fe2(CO3)3 + _2_Au (s)2Fe + Au2(CO3)3single replacement
  1. 2AgNO3 (aq) + ___ CuCl2 (aq)2AgCl + Cu(NO3)2double replacement
  1. _2_ NaCl (aq) + __Ca(OH)2 (aq)2NaOH + CaCl2double replacement
  1. __Na2SO4 (aq) + __Ca(NO3)2 (aq)CaSO4 + 2NaNO3double replacement

f._4__C2H5O (l) + _11__O2 (g)8CO2 + 10H2Ocombustion

Recognizing types of reactions from a diagram

Label each of the following diagrams as to the general type of chemical reaction of which it is representative.

synthesis

decomposition

single replacement

double replacement

CB – cation first

Physical vs. chemical changes

  1. Look at the following pictures. Based on each picture decide if what is represented in each picture is a “Physical” or “Chemical” process. Write your decision on the line beneath each picture:

______

Physical (evaporation)Chemical (Decomposition)

Chemical (synthesis)Physical (sublimation)

  1. A chemical reaction of an antacid produces bubbles of CO2 and water by the following equation:

NaHCO3 (s)NaHCO3 (aq)

NaHCO3 (aq)CO2 (g) + H2O (l)

  1. What would you observe in this reaction?

A gas bubbling out of a liquid

  1. Name at least one reason why this equation represents a chemical change.

The reactant is decomposing into new products