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Which statements about the organization of the elements in the periodic table are correct? I. Elements with atomic numbers 3, 11 and 19 have atoms with the same number of electrons in the outer energy level. II. Elements with atomic numbers 7, 15 and 33 have…
Fructose, C6H12O6, exists mainly as a ring, but a small proportion of the molecules in solution are in the straight-chain form shown. State the names of the functional groups present in the straight-chain form of fructose.
Which period 3 oxide forms a solution with pH > 7 when it is added to water? A. Al2O3 B. Na2O C. SiO2 D. SO2
A hydrogen ion reacts with a water molecule to form a hydronium ion. H2O + H+ → H3O+ What type of bond forms between the oxygen atom and the hydrogen ion? A. Ionic bond B. Hydrogen bond C. Covalent bond in which each atom supplies one electron to the…
Which row correctly states the types of intermolecular force present between molecules of ethane, methylamine and fluoromethane? A. Ethane: London (dispersion) forces only; methylamine: London forces, dipole-dipole forces and hydrogen bonding; fluoromethane:…
The structure of a compound is shown below. Atom (1) is the nitrogen atom of the ring, atom (2) is the ring carbon bonded to the triple bond and atom (3) is the terminal carbon of the triple bond. What is the molecular geometry around each of the numbered…
Which statements about alloys are correct? I. Alloys can contain non-metallic elements as well as metals. II. Alloys are usually softer than the pure metals they contain, because their layers slide over each other more easily. III. Atoms of different sizes…
Petrol (gasoline) is a mixture of hydrocarbons and can be blended with bioethanol. The carbon footprint of a fuel can be expressed as the mass of carbon dioxide, in kg, produced per kg of fuel burned. Calculate the carbon footprint of heptane, C7H16, in…
Petrol (gasoline) is a mixture of hydrocarbons and can be blended with bioethanol. The carbon footprint of a fuel can be expressed as the mass of carbon dioxide, in kg, produced per kg of fuel burned. State a reason why replacing part of the petrol with…
Ethyl 4-hydroxybenzoate is a preservative used in some oral medicines. It was synthesized by heating 0.745 g of 4-hydroxybenzoic acid with excess ethanol and a few drops of concentrated sulfuric acid as catalyst. C7H6O3 + C2H6O ⇌ C9H10O3 + H2O Mr…