Stoichiometry and Organic Chemistry Lecture Practice

Comprehensive practice flashcards covering chemical equilibrium, stoichiometry calculations, osmotic pressure, and organic chemistry structural concepts.

Solution A with $pOH = 10$ vs Solution B with $pOH = 12$

Solution A is more acidic than Solution B and has an $H_3O^+$ concentration that is $100$-times higher.

Solution A $c(H_3O^+)$ concentration at $pOH = 10$

$$1 \times 10^{-4} \, mol.l^{-1}$$

Products of $16.35 \, g$ Zinc reacting with sulfuric acid

$0.25 \, mol$ of $H_2$ ($500 \, mmol$) and $250 \, mmol$ of $ZnSO_4$ ($40.35 \, g$).

Ammonia synthesis from $4.5 \, mol$ of hydrogen

Produces $3 \, mol$ of ammonia, which is equivalent to $51 \, g$ or $67.2 \, dm^3$.

Glucose dose for a $20 \, kg$ child ($1.75 \, g/kg$ body weight)

$35 \, g$ of glucose, which corresponds to $35 \, ml$ or $116.66 \, ml$ depending on concentration.

Thermal decomposition of $7.5 \, g$ of calcium carbonate

Produces $4.2 \, g$ of $CaO$ and $1.68 \, dm^3$ of $CO_2$.

Combustion of $112 \, grams$ of sulfur

Requires $112 \, g$ of $O_2$ ($3.5 \, mol$) and produces $78.4 \, dm^3$ or $156.8 \, liter$ of $SO_2$.

Ferric chloride production from $0.5 \, mol$ of iron

Requires $16.8 \, dm^3$ ($0.75 \, mol$ or $53.25 \, g$) of chlorine to produce $81.25 \, g$ or $0.5 \, mol$ of $FeCl_3$.

Products of $23.4 \, g$ of potassium reacting with water

$0.6 \, mol$ of $KOH$ ($33.6 \, g$) and $0.3 \, mol$ of $H_2$ ($0.6 \, g$ or $600 \, mg$).

Reaction of $6 \, mol$ $NaOH$ with $1.8 \, mol$ $FeCl_3$

Forms $1.8 \, mol$ of $Fe(OH)_3$ ($192.6 \, g$), $5.4 \, mol$ of $NaCl$, and leaves $0.6 \, mol$ ($24 \, g$) of $NaOH$ unreacted.

Neutralization of $0.4 \, mol$ of oxalic acid

Requires either $0.8 \, mol$ of $LiOH$ or $0.4 \, mol$ of $Ba(OH)_2$ or $Mn(OH)_2$, or $0.3 \, mol$ of $Al(OH)_3$ (partial).

$LiOH$ concentration neutralized by $21 \, cm^3$ of $0.1 \, mol.dm^{-3} \, HCl$

$0.070 \, mol.l^{-1}$ or $70 \, mmol.l^{-1}$.

Neutralization of $30 \, ml \, HNO_3$ with $36 \, ml$ of $0.1 \, mol.dm^{-3} \, LiOH$

The $HNO_3$ concentration is $0.12 \, mol.l^{-1}$ ($120 \, mmol.l^{-1}$) and the amount of $LiOH$ used was $86.4 \, mg$.

$NaOH$ needed to neutralize $50 \, ml$ containing $1.5 \, mol$ sulfuric acid

$3 \, mol$ of $NaOH$ which equals $120 \, g$.

Equilibrium constant $K$ for $A + 2B \rightleftharpoons C$ ($[A]=0.5, [B]=1.6, [C]=2.56$)

$K = 2$; initial concentrations were $[A] = 2.1 \, mol.l^{-1}$ and $[B] = 4.16 \, mol.l^{-1}$.

Initial concentrations for $N_2 + 3 H_2 \rightleftharpoons 2 NH_3$ ($[N_2]=4.5, [H_2]=7, [NH_3]=8$)

Initial concentration of nitrogen ($[N_2]$) was $8.5 \, mol.l^{-1}$ and initial hydrogen ($[H_2]$) was $19 \, mol.l^{-1}$.

Phosphorus pentachloride decomposition equilibrium ($2$ of $8 \, moles$ in $10 \, L$)

$K = 0.067$, $[PCl_3] = 0.2 \, mol.l^{-1}$, $[Cl_2] = 0.2 \, mol.l^{-1}$, and $[PCl_5] = 0.6 \, mol.l^{-1}$.

Equilibrium state of $H_2 + I_2 \rightleftharpoons 2HI$ ($[H_2]=0.50, [I_2]=0.30, [HI]=1.6$)

$K = 17.067$; initial concentrations were $[H_2] = 1.3 \, mol.l^{-1}$ and $[I_2] = 1.1 \, mol.l^{-1}$.

Osmotic pressure of $KCl$ ($3 \, g$ in $0.5 \, liter$ at $30 \, ^{\circ}C$)

$403.6 \, kPa$ with an osmotically active particle concentration of $0.16 \, mol.l^{-1}$.

Osmotic pressure of non-electrolyte ($75 \, mmol$ in $250 \, ml$ at $37 \, ^{\circ}C$)

$774.13 \, kPa$ with an osmotically active particle concentration of $0.3 \, mol.l^{-1}$.

Glucose isotonicity

The resulting solution with $0.3 \, mol.l^{-1}$ particles is hypertonic to the $NaCl$ physiological solution.

Molecular weight of a non-electrolyte in $1 \, liter$ ($7.256 \, g$ at $100 \, kPa, 25 \, ^{\circ}C$)

$180$, which can be fructose or glucose.

Molecular weight of carbohydrate ($12.61 \, g$ in $300 \, ml$ at $700 \, kPa, 27 \, ^{\circ}C$)

$150$, which can be xylulose, ribulose, or ribose.

Propane combustion ($44.8 \, dm^3$)

Consumes $224 \, liters$ ($10 \, moles$) of $O_2$ and forms $8 \, moles$ ($144 \, g$) of $H_2O$.

Reaction of $92 \, mg$ sodium with $5 \, mmol$ ethanol

Releases $0.002 \, mol$ ($2 \, mmol$) of $H_2$ and leaves $20 \, \%$ of ethanol unreacted.

Mass of sucrose for $1 \, tonne$ of glucose

$1,900 \, kg$ ($1.9 \, tonnes$) of sucrose ($C_{12}H_{22}O_{11}$) from $9,500 \, kg$ of sugar cane.

Methane explosive limits ($1.12 \, m^3$ mixture)

$40 - 120 \, g$ ($2.5 - 7.5 \, mol$) of methane corresponds to the $5$ to $15 \, \%$ volume range.

Ethane production from $13 \, g$ acetylene and $44.8 \, L$ hydrogen

$0.5 \, mol$ of ethane is produced, equaling $15 \, g$ or $11.2 \, liters$.

Dichloroethane preparation (from $49.5 \, g$ material)

Requires $11.2 \, liters$ ($14 \, g$) of ethene and $11.2 \, liters$ ($35.5 \, g$) of chlorine.

Benzene preparation from $6.72 \, dm^3$ acetylene ($50 \, \%$ yield)

$3.9 \, g$ ($3.9 \times 10^{-3} \, kg$ or $3,900 \, mg$) of benzene ($C_6H_6$).

Toluene preparation from $26 \, g$ benzene

Produces $30.66 \, g$ toluene and consumes $16.83 \, g$ ($0.333 \, mol$) of chloromethane ($CH_3Cl$).

Methyl formate (Methyl methanoate)

An ester of formic acid with formula $HCOOCH_3$; $6 \, g$ reacts with $50 \, ml$ of $2 \, mol.l^{-1} \, NaOH$.

Phenolate preparation from $47 \, g$ phenol and $47 \, g \, KOH$

$66 \, g$ ($0.066 \, kg$ or $0.5 \, mol$) of potassium phenolate ($C_6H_5OK$).

Ethyl formate preparation ($222 \, g$)

Requires $138 \, g$ ($3 \, mol$) of formic acid ($HCOOH$) and $138 \, g$ ($3 \, mol$) of ethanol ($C_2H_5OH$).

Ethyl acetate preparation for $22 \, g$ yield ($25 \, \%$ theoretical yield)

Requires $46 \, g$ ($1 \, mol$) of ethanol ($CH_3CH_2OH$).

Electron configuration of carbon (excited state)

$1s^2 \, 2s^1 \, 2p_x^1 \, 2p_y^1 \, 2p_z^1$ (or $1s^2 \, 2s^1 \, 2p^3$).

Characteristics of organic compounds

Depend on types of functional groups, structure, constitution, and internal arrangement of atoms.

Methane molecule ($CH_4$) structure

A four-bonded carbon in the center of a regular tetrahedron with binding angles of $109^{\circ} \, 28'$.

Secondary carbon atom

A carbon atom bonded to two other carbon atoms, such as the atoms marked $2$ or $3$ in butanone.

Tertiary carbon atom

A carbon atom bonded to three other carbon atoms, as found in $(CH_3)_3C-OH$.

Constitutional isomers

Compounds with the same molecular formula but different structural formulas (e.g., n-pentane and isopentane or ethyl alcohol and dimethyl ether).

Cis-trans isomerism examples

Possible in 2-butene, 3-hexene, 1,2-dichloroethylene, 9-octadecenic acid, and butenedioic acid.

Ethyl acetate (Ethyl ester of acetic acid)

Represented by the formulas $CH_3-CO-O-CH_2-CH_3$ and $CH_3-CH_2-O-CO-CH_3$.

Butanone

A চার-carbon ketone structure often used to illustrate secondary carbon atoms.

Isopentane vs 2-methylbutane

Different names for the same constitutional isomer of pentane.

Gas constant $R$ used in osmotic calculations

$8.32 \, J.K^{-1}mol^{-1}$.

Binding angle of $120^{\circ}$

The angle characteristic of double-bonded carbon atoms (not methane).

Butenedioic acid

An organic acid that exhibits cis-trans isomerism.

Tautomers

Constitutional isomers that readily interconvert, though not the relationship represented by the ethyl acetate/ethyl ester pair.