Chemical industry

• What colour is ammonia?


  colourless
• What state is ammonia and what is its smell? gas, strong smell
• How reactive is ammonia? and why is this? unreactive due to strong triple bond holding atoms together. A lot of energy is needed to break this bond (extremely high bond enthalpy) A temperature of 450c and iron catalysts are needed.
• What can Ammonia also be called? A nitrogen hydride (NH3)
• What can Ammonia act as and why? Ammonia can act as a base due to its lone pair on the nitrogen. This allows it to form a dative bond with a hydrogen ion.
• name NO


  Nitrogen oxide
• Name NO2


  Nitrogen dioxide
• Name N2O


  Dinitrogen oxide
• What is the appearance of NO: colourless gas, turns to brown NO2 in air
• What is the appearance of NO2


  Brown gas
• What is the appearance of N2O


  Colourless gas
• Where does NO come from? Combustions process, especially through vehicle engines, thunderstorms, formed in the soil by denitrifying bacteria.
• Where does NO2 come from? From oxidation of NO in the atmosphere
• Where does N2O come from? Formed in the soil by denitrifying bacteria
• What is the test for Nitrate (V) ions? Add sodium hydroxide solution & Devarda's Alloy, Cu/Al/Zn and gently heat. A positive test produces Ammonia gas. Ammonia makes damp red litmus paper blue. Forms whites fumes of ammonium chloride when it comes into contact with hydrogen chloride.
• What is the test for Ammonium ions ? (NH4+): add Sodium Hydroxide solution and gently heat. A positive test = ammonia gas given off.
• Give the equations for forming Nitrogen (IV) dioxide from Nitrogen (II) oxide in a combustion process: N2 + O2 --> 2NO

  2NO + O2 --> 2NO2
• Define: rate of reaction: The change in the amount or concentration of a reactant or product per unit of time.
• Define: rate constant: a measure of the speed of a chemical reaction
• Define: order of reaction: the relationship between the rate of a chemical reaction and the concentration of the species taking part in it.
• Rate of reaction =


  change in property/time taken
• What is the general rate equation?


  rate=k[A]^m[B]n
• What does m & n represent in the rate equation? The concentrations (usually have the value 1,2 or 3)
• What are the terms m & n called? order of reaction
• What is the Arrhenius equation?


  k=Ae^(-Ea/RT)
• What is the rate determining step? The step with the lowest rate
• What is k in the Arrhenius equation? the rate constant
• What is Ea in the Arrhenius equation? The activation enthalpy
• What is T in the Arrhenius equation? Temperature in Kelvin
• What is R in the Arrhenius equation? The gas constant (8.31J K⁻¹ mol⁻¹)
• What is A in the Arrhenius equation?


  pre-exponential factor
• If a reactant isn't in the rate equation, it cant be the...: rate-determining step
• What is the half-life of a reactant? The time it takes for half of the reactant to react
• What is rate of reaction usually measured in? mol dm−3 s−1
• What equation can be used to calculate the rate constant from half-life? Which orders does it apply for? k=ln2÷t12 Only applies to first order reactants (because with other orders, the half-life is constantly changing
• In a rate equation, what do the superscript integers represent? The order of that reactant/catalyst
• What is Devarda's alloy? An alloy made from aluminium and copper
• The order of a reactant can only be determined with ___. (can be multiple words): Experimental data
• How is nitrogen gas formed in the nitrogen cycle? Nitrate(V) ions + H+ + e-
• What is the effect of adding a catalyst on the equilibrium constant? None