Chemistry Questions

Given the balanced equation representing a reaction:Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g)This reaction occurs more quickly when powdered iron is used instead of a single piece of iron of the same mass because the powdered iron(1) acts as a better catalyst than the single piece of iron(2) absorbs less energy than the single piece of iron(3) has a greater surface area than the single piece of iron(4) is more metallic than the single piece of iron
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Which formula represents a polar molecule?(1) Br2 (3) CH4(2) CO2 (4) NH3
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Which terms are used to identify pure substances?(1) an element and a mixture(2) an element and a compound(3) a solution and a mixture(4) a solution and a compound
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The percentage by mass of Br in the compoundAlBr3 is closest to(1) 10.% (3) 75%(2) 25% (4) 90.%
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SELECT ALL THAT APPLYat STP conditions, 0.25 moles of CO2(g), H2(g), NH3(g)1. Will contain the same number of molecules 2. Will contain the same number of atoms3. Will occupy the same volume4. Will have the same g.f.w
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Molecules of 1-bromopropane and 2-bromopropane differ in(1) molecular formula(2) structural formula(3) number of carbon atoms per molecule(4) number of bromine atoms per molecule
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Based on intermolecular forces, which of these substances would have the highest boiling point?(1) He (3) CH4(2) O2 (4) NH3
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A specific amount of energy is emitted when excited electrons in an atom in a sample of an element return to the ground state.This emitted energy can be used to determine theA) mass of the sample B) volume of the sample C) identity of the element D) number of moles of the element
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How do the energy and the most probable location of an electron in the third shell of an atom compare to the energy and the most probable location of an electron in the first shell of the same atom?(1) In the third shell, an electron has more energy and is closer to the nucleus.(2) In the third shell, an electron has more energy and is farther from the nucleus.(3) In the third shell, an electron has less energy and is closer to the nucleus.(4) In the third shell, an electron has less energy and is farther from the nucleus.
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Which ion is most easily reduced?(l ) Zn2+ (2) Mg2+ (3) Co2+ (4) Ca2+
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From which of these atoms in the ground state can a valence electron beremoved using the least amount of energy?(1) nitrogen (3) oxygen(2) carbon (4) chlorine
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In terms of energy and entropy, systems in nature tend to undergo changes toward(1) higher energy and higher entropy(2) higher energy and lower entropy(3) lower energy and higher entropy(4) lower energy and lower entropy
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Which formula represents lead(II) chromate?(1) PbCrO4 (3) Pb2CrO4(2) Pb(CrO4)2 (4) Pb2(CrO4)3
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Which compound has hydrogen bonding between its molecules?(1) CH4 (3) KH(2) CaH2 (4) NH3
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What is the total number of electrons found in an atom of sulfur?(1) 6 (2) 8 (3) 16 (4) 32
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Which element is malleable and a good conductor of electricity at STP?(1) argon (3) iodine(2) carbon (4) silver
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Do Sugar Crystals Grow Faster In Tap Water Or In Distilled Water?
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In which type of reaction do two lighter nuclei combine to form one heavier nucleus?(1) combustion (3) nuclear fission(2) reduction (4) nuclear fusion
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