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Benzene is converted into nitrobenzene by heating it with a mixture of concentrated nitric and sulfuric acids. The attacking species is the electrophile NO2+. Explain the mechanism by which benzene is nitrated by NO2+, showing the movement of…
The rate constant of a reaction at 40 °C is 2.5 times its value at 30 °C. Deduce the activation energy of the reaction, in kJ mol−1. Use sections 1 and 2 of the data booklet.
Proteins are polymers of amino acids. State the type of bonding that joins the amino acids together along a polypeptide chain.
A biochemist wants to find out which of the amino acids glycine, serine and leucine are present in a short peptide. Outline how paper chromatography can be used to do this.
The concentration of protein in egg white was determined by a dye-binding method. The absorbance at 595 nm of protein solutions of known concentration was used to draw a calibration line, with the equation shown. Calculate, using the linear equation, the…
Palmitic acid, CH3(CH2)14COOH, and palmitoleic acid, CH3(CH2)5CH=CH(CH2)7COOH, which has a cis C=C double bond, both have a chain of sixteen carbon atoms. Predict which of the two fatty acids has the higher melting point and give two reasons for…
Which solutions would show a wavelength of maximum absorbance different from that of 0.10 mol dm−3 CuSO4(aq)? I. 0.010 mol dm−3 CuSO4 II. 0.10 mol dm−3 Cu(NO3)2 III.…
Sucrose, a disaccharide, forms when a molecule of glucose joins a molecule of fructose. State the type of reaction by which two monosaccharides join to form a disaccharide.
The wavelength of maximum absorbance of an aqueous solution of 0.10 mol dm−3 CuSO4 is measured. Which aqueous solutions would have a different wavelength of maximum absorbance? I. 0.050 mol dm−3 Cu(NO3)2 II.…
Maltose is a disaccharide made of two glucose units. State the type of reaction in which a disaccharide forms from two monosaccharide molecules.