Memorization Quiz #2

Warmup: Write a balanced equation for the reaction that occurs when: Liquid carbon disulfide reacts with oxygen gas to produce carbon dioxide and sulfur dioxide gas. CS 2 (l) + O 2 (g)  CO 2 (g) + SO 2 (g) Solid aluminum metal reacts with aqueous zinc (II) chloride to produce solid zinc metal and aqueous aluminum chloride. Al(s) + ZnCl 2 (aq)  Zn(s) + AlCl 3 (aq)

The 5 Main Types of Chemical Reactions We may occasionally run into a reaction that does not fit into any category, or fits into several different ones. Don’t stress!

Synthesis (Combination): Two (or more) elements combine to form one, complicated compound. A + X  AX 2Fe (s) + O 2 (g)  2FeO (s) 2 reactants1 product

Predicting Products of Synthesis Reactions: Mg (s) + O 2(g) → C (s) + O 2(g) → Na (s) + Cl 2(g) → MgO (s) CO 2(g) NaCl (s) 2 Predicting products can be tough. I will test you on very obvious ones. For homework and class problems, just try to come up with likely products, ok? 2 22

Decomposition Reactions One compound produces two or more simpler substances. A X  A + X CaCO 3 (s)  CaO(s) + CO 2 (g) Ca C O O O C O O O +

Predicting Products of Decomposition Reactions: HgO (s) → (demo!!!) KClO 3(s) → H 2 SO 4(s) → Hg (s) + O 2(g) KCl (s) + O 2(g) H 2 O (l) + SO 3(g)

Single Replacement (Displacement): one ion replaces a similar ion to make a new compound A + BX  AX + B 2Al (s) + 3Pb(NO 3 ) 2 (aq)  2Al(NO 3 ) 3 (aq) + 3Pb (s) Notice that nitrate doesn’t separate…

Predicting Products of SR Reactions I 2(l) + NaBr (aq) → Zn (s) + HCl (aq) → Fe (s) + CuSO 4(aq) → NaI (aq) + Br 2(l) ZnCl 2(aq) + H 2(g) FeSO 4(aq) + Cu (s) 2 2 2

Double Replacement (Displacement) Reactions: The cations and anions of 2 ionic compounds switch places in an aqueous solution, forming 2 new ionic compounds A X + BY  AY + BX NaCl (aq) + AgNO 3 (aq) → NaNO 3 (aq) + AgCl (s)

Predicting Products of DR Reactions AlCl 3(aq) + Na 2 SO 4(aq) → HCl (aq) + FeS (s) → H 2 SO 4 (aq) + NaOH(aq) → (demo on next slide…..) NaCl (aq) + Al 2 (SO 4 ) 3(s) FeCl 2(aq) + H 2 S (g)

BEVERAGE MAGIC 1. water to wine 2. wine back to water H 2 SO 4 (aq) + NaOH(aq) → HOH(l) + Na 2 SO 4 (aq) What type of reaction is this? 3. water to milk Na 2 SO 4 (aq) + BaCl 2 (aq)→ BaSO 4 (s) + 2NaCl(aq) What type of reaction is this? 4. milk to strawberry shake

Combustion of Hydrocarbons: One reactant mixes with oxygen gas, releasing energy in the form of heat and light. Water vapor is always made. Sometimes carbon dioxide is also made. C 3 H 8 (g) + 5O 2 (g)  3CO 2 (g) + 4H 2 O(g)

Predicting Products of Hydrocarbon Combustion C 3 H 7 OH (l) + O 2(g) → C 4 H 10(g) + O 2(g) → C 12 H 22 O 12 + O 2 → Demo on next slide! CO 2(g) + H 2 O (g)

The Gummi Bear Electric Chair first reaction: heat + NaClO 3 → NaCl + O 2 oxygen fuels the second reaction C 12 H 22 O 12 + O 2 → CO 2 + H 2 O + heat

Classify each rxn with a buddy, 3 minutes 1. HCl (aq) + FeS (s) → FeCl 2(aq) + H 2 S (g) 2. C 2 H 2 + O 2  CO 2 + H 2 O 3. NaBr + Ca(OH) 2  CaBr 2 + NaOH 4. H 3 PO 4 + LiOH  Li 3 PO 4 + H 2 O 5. NH 3 + H 2 SO 4  (NH 4 ) 2 SO 4 6. AgBr + Hg  HgBr 2 + Ag

Write reactants. Predict products. Balance. 1. Sulfuric acid is added to solid calcium phosphate H 2 SO 4 (aq) + Ca 3 (PO 4 ) 2 (s) → CaSO 4 + H 3 PO 4 2. Hydrogen sulfide gas is bubbled into a mercury(II)chloride solution H 2 S(g) +HgCl 2 (aq) → HgS + HCl

Write reactants. Predict products. Balance. 3. A bar of zinc metal is immersed in a solution of copper(II) nitrate Zn(s)+ Cu(NO 3 ) 2 (aq)→ Zn(NO 3 ) 2 (aq) + Cu(s) 4. Ethanol is burned in oxygen C 2 H 5 OH(l) + O 2 (g) → CO 2 (g) + H 2 O(g) 32 3