CHM113 Chapter 4A: Chemical Reactions

Flashcards for General Chemistry I (CHM113) Chapter 4A covering reaction types, balancing equations, solubility rules, electrolytes, and net ionic equations.

What do the chemical phase symbols $(s)$, $(l)$, $(g)$, and $(aq)$ represent in a chemical equation?

$(s)$ represents solid, $(l)$ represents liquid, $(g)$ represents gas, and $(aq)$ represents an aqueous solution where water is the solvent.

What is the key rule regarding coefficients and subscripts when balancing a chemical equation?

You can change coefficients in front of chemical formulas, but you must never change subscripts within formulas.

What is the recommended order of elements to follow when balancing a chemical equation?

Balance elements appearing only once on each side first, typically balancing metals first, then non-metals, and finally hydrogen and oxygen.

What is the balanced chemical equation for $CHNO + O_2 \rightarrow CO_2 + H_2O + NO_2$ using integer coefficients?

$$4CHNO + 7O_2 \rightarrow 4CO_2 + 2H_2O + 4NO_2$$

What are the primary types of chemical reactions discussed in Chapter 4A?

Combination, decomposition, single displacement, double displacement, precipitation, gas forming, and acid-base neutralization.

What criterion determines whether a single displacement reaction will take place between a metal and an aqueous ionic compound?

Metal activity: a free metal will displace another metal from a compound only if it is more active than the metal in the compound.

Based on the reactivity series of metals, will the reaction $Cu(s) + FeCl_2(aq) \rightarrow CuCl_2(aq) + Fe(s)$ occur?

No reaction occurs because copper ($Cu$) is less active than iron ($Fe$).

What visual indicator differentiates an electrolyte solution from a non-electrolyte solution in a electrical conductivity setup?

An electrolyte solution conducts electricity and lights the bulb, whereas a non-electrolyte solution does not conduct electricity and the bulb remains unlit.

What are spectator ions in a chemical reaction?

Spectator ions are ions present in the solution that do not participate in the chemical reaction and remain unchanged on both sides of the ionic equation.

What is the net ionic equation for the precipitation reaction $NaCl(aq) + AgNO_3(aq) \rightarrow NaNO_3(aq) + AgCl(s)$?

$$Ag^+(aq) + Cl^-(aq) \rightarrow AgCl(s)$$

Which ions act as spectator ions in the reaction $NaCl(aq) + AgNO_3(aq) \rightarrow NaNO_3(aq) + AgCl(s)$?

$Na^+(aq)$ and $NO_3^-(aq)$

According to the solubility rules, what are the exceptions to the solubility of nitrate ($NO_3^-$) and acetate ($CH_3COO^-$) compounds?

There are no exceptions; all compounds containing $NO_3^-$ or $CH_3COO^-$ are soluble.

Which metal cations form insoluble exceptions when paired with chloride ($Cl^-$), bromide ($Br^-$), or iodide ($I^-$) ions?

$Ag^+$, $Hg_2^{2+}$, and $Pb^{2+}$

What products are formed in the gas-forming double displacement reaction $Na_2CO_3(aq) + H_2SO_4(aq) \rightarrow \text{?}$

$$Na_2SO_4(aq) + CO_2(g) + H_2O(l)$$

Which intermediate compound decomposes into water and carbon dioxide gas during a carbonate gas-forming reaction?

Carbonic acid ($H_2CO_3$)

What is the net ionic equation for the acid-base neutralization reaction $2NaOH(aq) + H_2SO_4(aq) \rightarrow Na_2SO_4(aq) + 2H_2O(l)$?

$$H^+(aq) + OH^-(aq) \rightarrow H_2O(l)$$

What shortcut can be used when balancing double displacement reactions involving polyatomic ions in aqueous solutions?

Balance polyatomic ions as single intact units rather than balancing their individual constituent atoms.

What is the balanced molecular equation for $(NH_4)_2SO_4(aq) + BaCl_2(aq) \rightarrow BaSO_4(s) + NH_4Cl(aq)$?

$$(NH_4)_2SO_4(aq) + BaCl_2(aq) \rightarrow BaSO_4(s) + 2NH_4Cl(aq)$$

What is the balanced molecular equation for the double displacement reaction between $Pb(NO_3)_2(aq)$ and $KI(aq)$?

$$Pb(NO_3)_2(aq) + 2KI(aq) \rightarrow PbI_2(s) + 2KNO_3(aq)$$