Zadania z chemii IB HL

Pentadecane produced by cyanobacteria can be used as a biofuel. Explain why burning this biofuel adds less to the long-term buildup of atmospheric carbon dioxide than burning the same mass of pentadecane refined from crude oil.

Pentadecane can be cracked into smaller molecules. Consider the reaction: $\ce{C15H32(g) -> 3C4H8(g) + C3H8(g)}$ where $\ce{C4H8}$ is but-1-ene. (i) Use the bond enthalpies in section 12 of the data booklet to determine $\Delta H^\ominus$ for this reaction.…

But-1-ene is converted into butan-2-ol in a single reaction. State the corresponding equation.

Butan-2-ol reacts with octadecanoic (stearic) acid to form an ester that is used as a lubricant. $\ce{C17H35COOH(l) + CH3CH(OH)CH2CH3(l) <=> C17H35COOCH(CH3)CH2CH3(l) + X(l)}$ (i) Identify the by-product X(l) and state the type of reaction taking place. (ii)…

The equilibrium constant, $K_\mathrm{c}$, for the reaction in (f) is $6.4 \times 10^{-5}$ at 80 °C. (i) $1.00\ \mathrm{dm^3}$ of a mixture that is initially $0.20\ \mathrm{mol\,dm^{-3}}$ in octadecanoic acid and $0.20\ \mathrm{mol\,dm^{-3}}$ in butan-2-ol is…

Ammonium ions and phosphate ions combine to form an ionic compound. What is its formula? A. $\ce{NH4PO4}$ B. $\ce{(NH4)2PO4}$ C. $\ce{(NH4)3PO4}$ D. $\ce{NH4(PO4)3}$

(i) Iodine molecules, $\ce{I2}$, undergo homolytic fission when they absorb light. Write an equation for this process, using curly arrows to show the movement of the electrons. (ii) In the presence of a suitable reagent the I–I bond can instead break…

The boiling points of the five simplest straight-chain primary amines, $\ce{CH3NH2}$ to $\ce{CH3(CH2)4NH2}$, and of the five simplest 1-fluoroalkanes, $\ce{CH3F}$ to $\ce{CH3(CH2)4F}$, are plotted below against the number of carbon atoms in the molecule. An…