Reacting masses, volumes and concentrations

(i) The first step is the catalytic oxidation of ammonia gas to nitrogen monoxide. $\ce{4NH3(g) + 5O2(g) -> 4NO(g) + 6H2O(g)}$ Determine the volume, in dm$^3$, of nitrogen monoxide produced from 20.0 g of ammonia, at STP, using section 2 of the data booklet.…

(i) Determine the enthalpy of combustion of pentane, in kJ mol$^{-1}$, using table 12 in the data booklet. $\ce{C5H12(g) + 8O2(g) -> 5CO2(g) + 6H2O(g)}$ (ii) Calculate the mass, in g, of carbon dioxide, $\ce{CO2}$, produced when 45.0 g of pentane react with…

A sample of the sodium hydroxide solution is gradually added to 25.0 cm$^3$ of an aqueous solution of an unknown organic acid, producing the following pH curve. Calculate the concentration of the unknown organic acid.

(i) Suggest, giving a reason for each, two different safety precautions that should be taken when carrying out either of these preparations. (ii) Deduce the coefficients needed to balance the following equation for the reaction of silver with concentrated…

Gallium forms a sulfate of formula $\ce{Ga2(SO4)3}$. (i) Both ionic and covalent bonding are present in this compound. State which particles are held together by each type of bond. (ii) Contrast covalent and ionic bonds in terms of what happens to the valence…

What volume of propane gas, in $\mathrm{cm^3}$, must be burned completely in oxygen to give 90 $\mathrm{cm^3}$ of carbon dioxide, all volumes being measured at the same temperature and pressure? $\ce{C3H8(g) + 5O2(g) -> 3CO2(g) + 4H2O(g)}$ A. 18 B. 30 C. 90 D.…

A chemist treated 22.99 g of galantamine with sulfuric acid to make the sulfate salt: $\ce{2C17H21NO3 + H2SO4 -> (C17H22NO3)2SO4}$ The mass of salt isolated was 24.65 g. Determine the percentage yield of the salt. Use section 7 of the data booklet.

What amount of oxygen, in mol, is required to burn 8.72 g of butane, $\ce{C4H10(g)}$, completely? $M$(butane) = 58.14 $\mathrm{g\,mol^{-1}}$ A. 0.0231 B. 0.150 C. 0.975 D. 1.95

(i) If the reaction has a percentage yield of 80 %, calculate the mass, in g, of benzene that would be produced from 2.0 kg of cyclohexane. (ii) Calculate the atom economy for this reaction, as a percentage.

Hexanoic acid, $\ce{CH3(CH2)4COOH}$, is a weak acid. The graph shows how the pH changes during the titration of a 20.0 $\mathrm{cm^3}$ aqueous solution of hexanoic acid with aqueous sodium hydroxide. (i) Deduce an expression for the equilibrium constant, $K$,…

What volume of hydrogen, in $\mathrm{cm^3}$, is produced at STP when 0.810 g of aluminium reacts with an excess of hydrochloric acid? $\ce{2Al(s) + 6HCl(aq) -> 2AlCl3(aq) + 3H2(g)}$ Molar volume of an ideal gas at STP = 22.7 $\mathrm{dm^3\,mol^{-1}}$ A. 341 B.…

A $20.00\ \mathrm{cm^3}$ sample of a solution containing 1.21 g of HA is titrated with $0.500\ \mathrm{mol\,dm^{-3}}$ sodium hydroxide solution, NaOH(aq). Exactly $27.40\ \mathrm{cm^3}$ of the NaOH(aq) is required to neutralize the acid completely. Determine…

When $10.0\ \mathrm{cm^3}$ of a gaseous hydrocarbon, $\ce{C_xH_y}$, is burned completely, $70.0\ \mathrm{cm^3}$ of gaseous products is formed. This volume falls to $30.0\ \mathrm{cm^3}$ when the water vapour condenses. All volumes are measured at the same…

Propane hydrate, $\ce{C3H8.17H2O}$ ($M_r = 350$), is a crystalline solid that can form in natural gas pipelines at low temperature. What mass of carbon dioxide is produced by the complete combustion of 17.5 g of propane hydrate? A. 2.20 g B. 6.60 g C. 17.5 g…

In a redox titration, dichromate(VI) ions are reduced to chromium(III) ions and iron(II) ions are oxidized to iron(III) ions. $\ce{Cr2O7^2-(aq)}$ reduced to $\ce{Cr^3+(aq)}$ $\ce{Fe^2+(aq)}$ oxidized to $\ce{Fe^3+(aq)}$ What volume, in $\mathrm{cm^3}$, of…