Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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what is it called when there are two of the same element that have the …
B. isotope
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when two intermediate chemical equations are combined, the same substan…
It is a reactant in one intermediate reaction and a product in the other
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consider these intermediate chemical equations. 2p(s) + 3cl₂(g) → 2pcl₃…
\(PCl_3\)
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consider these intermediate chemical equations. ca(s) + co₂(g) + 1/2o₂(…
is halved and has its sign changed.
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what is enthalpy? the total pressure of the system the total disorder o…
the total heat content of the system
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if a chemical reaction is reversed, what happens to the enthalpy of the…
The sign of the enthalpy of the reaction reverses.
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consider these intermediate chemical equations. ch₄(g)+2o₂(g)→co₂(g)+2h…
$CH_4(g)+2O_2(g) ightarrow CO_2(g)+2H_2O(g)+2H_2O(l)$
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enthalpy of reaction reaction energy the table shows the enthalpy value…
$\Delta H=(4\times413 + 2\times495)-(2\times799+4\times463)$
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when mixed into water, a strong acid will form a suspension. dissociate…
B. dissociate into ions.
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which of the following is both an anion and a compound? hco₃⁻ nacl k⁺ c…
$HCO_3^-$
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if an element is composed of atoms with an atomic number of 6 and a mas…
6 protons and 8 neutrons.
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the chemical notation that indicates concentration is represented as ()…
D. []
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this is how fluorine appears in the periodic table. which is one piece …
the atomic number
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the element phosphorus is located to the right of the element magnesium…
Phosphorus has a larger atomic mass.
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which two chemists organized elements based on properties such as how t…
A. Lavoisier and Mendeleev
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question 7 1 part | -- of 1 point a cation has a ______ charge. covalen…
E. positive
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this is how zirconium appears in the periodic table. rounded to the nea…
40
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while developing his periodic table, dmitri mendeleev broke his own rul…
Mendeleev observed that tellurium has chemical properties like other elements in its group, and he did not know that neutrons cause the greater atomic mass.
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based on the information in the table, which elements are most likely i…
Aluminum, boron, and gallium are likely together in one group because they have the same number of valence electrons, and carbon and germanium are likely together in another group…
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in an elements square on the periodic table, the number with the greate…
atomic mass.
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while looking at calcium (ca) on the periodic table, a student needs to…
directly to the right
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part of one row of the periodic table is shown. which elements atoms ha…
C. tellurium (Te)
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question 3 1 part | -- of 1 point water has the ability to dissolve mol…
C. forming hydration spheres around the molecule.
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using caution with chlorine chlorine is a respiratory irritant that can…
D. Gaseous chlorine—mucous membrane irritation
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describing uses for mercury mercury is widely used in labs for thermome…
C. Caustic soda and chlorine
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written in this form, na+ means an electron has been lost. sodium is an…
A. an electron has been lost.
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question 1 1 part | -- of 1 point the molecule co₂ is carbon oxide. car…
C. carbon dioxide
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identifying the properties of platinum locate the element platinum (pt)…
Melting point: 1768.3 Boiling point: 3825
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locate the element xenon (xe) on the periodic table and click on the sq…
C. noble gas
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using enthalpy diagrams consider these equations. ch₄(g) → c(s) + 2h₂(g…
represents the overall enthalpy of reaction
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using enthalpy diagrams consider these equations: ch₄(g) → c(s) + 2h₂(g…
has a magnitude that is greater than that of B
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using enthalpy diagrams consider these equations. ch₄(g) → c(s) + 2h₂(g…
exothermic
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using enthalpy diagrams consider these equations ch₄(g) → c(s) + 2h₂(g)…
$74.6\text{ kJ}$
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directions: read the passage below and answer the following questions. …
1. A wave is a disturbance that travels through a medium with regular vibration or oscillating motion. 2. Water wave, light wave, sound wave, seismic wave. 3. Mechanical wave and …
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using enthalpy diagrams use the enthalpy diagram to answer this questio…
exothermic
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using enthalpy diagrams. use the enthalpy diagram to answer this questi…
A. A and D
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ons: $delta h_1=-393.5\text{kj}$ $delta h_2 = - 566.0\text{kj}$ $delta …
$852.85$
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applying hesss law consider the intermediate equations: c(s) + o₂(g) → …
The third equation must be reversed; The third equation must be halved
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consider the chemical equations shown here. c(s) + 2h₂(g) → ch₄(g) c(s)…
$CH_4(g)+4Cl_2(g) ightarrow CCl_4(g)+4HCl(g)$
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consider the equations. (1) ca(s) + co₂(g) + 1/2o₂(g) → caco₃(s) (2) 2c…
multiply equation (2) by $\frac{1}{2}$
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consider the equations. (1) fe₂o₃(s) → 2fe(s) + ³/₂o₂(g) (2) fe₂o₃(s) +…
\(3CO(g)+\frac{3}{2}O_2(g) ightarrow3CO_2(g)\)
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consider the equations. h₂ → 2h c₂h₄ + h → c₂h₅ c₂h₅ + h → c₂h₆ when th…
$C_2H_4 + H_2 ightarrow C_2H_6$
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complete the table. property description importance to life polarity hy…
| Property | Description | Importance to Life | |--|--|--| | Polarity | Hydrogen and oxygen within water molecules form a chemical bond that involves sharing of electron pairs bet…
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select the correct answer. lawrence wants to check the acidity of a sam…
B. a pH meter
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which of the following is an important aspect of an experiment? testing…
constant conditions
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question some products contain hydrogenated vegetable oils. select whic…
They have no double bonds between the carbon atoms They are solid at room temperature Margarine is made with hydrogenated vegetable oil
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the density of water is _____. 1.0 g/ml 0.1 g/ml 10 g/l none of these
A. 1.0 g/mL
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question① why is water particularly effective as a solvent? answer its …
Its polarity creates positive and negative regions that interact with many types of molecules.
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which of the following is a type of molecule that releases hydrogen ion…
C. An acid
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question which of the following statements about the ph scale are true?…
A. A solution with a pH of 7 has an equal number of hydrogen and hydroxide ions. B. The pH scale is a logarithmic scale based on powers of 10. D. A solution with a pH of 2 has 100…
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question 7 which of the following is the property of water that arises …
High heat capacity
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physical versus chemical changes _____15. what is the most important qu…
15. b. Did the composition change? 16. a. electrolysis 17. physical change 18. CC 19. PC 20. CC 21. PC 22. CC 23. CC 24. PC 25. PC
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question 1 which of the following statements about the following reacti…
B. Buffers prevent large changes in pH. C. The reaction indicates a dissociation of a weak acid. D. The reaction indicates that a proton can be donated or accepted.
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drag and match determine which of the following is a base, acid or salt…
Acid: HCl Salt: NaCl Base: KOH, NaOH Alkaline: KOH, NaOH
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question which of the following ph values are more acidic? select all t…
B. pH 4, C. pH 2
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learning: chapter 02: sections 5 - 8 question the ideal medium for most…
D. blood
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question ① the action of a buffer to maintain ph within normal limits i…
removing or replacing hydrogen ions
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name directed reading a continued chemical changes and new substances 9…
9. b. change into new substances. 10. c. the melting of a Popsicle 11. Ingredients react to form a new substance with different properties. Chemical reactions like decomposition o…
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question ① ph measures the concentration of ____________ in a solution.…
C. free hydrogen ions
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section: chemical properties chemical properties 1. the property of mat…
1. c. chemical property 2. a. reactivity 3. b. flammability 4. d. oxygen in the air 5. b. Characteristic properties may be either physical or chemical properties. 6. Burning wood …
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what would coffee, at a ph of 4, be considered? acidic a buffer basic
A. acidic
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on the ph scale, what is considered basic? above 7 below 7 7
above 7
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question which of the following statements about the following reaction…
The reaction indicates a dissociation of a weak acid. Buffers prevent large changes in pH. The reaction indicates that a proton can be donated or accepted.
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how is ph measured? it is a percentage between 1 and 100. it is a level…
It is based on a scale of 0 to 14.
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what is a base? a solution that has more hydrogen (h+) ions when water …
a solution that has more hydroxide (OH-) ions when water breaks down into ions
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what is a buffer? a strong acid that keeps the ph low a weak acid or ba…
a weak acid or base that keeps the pH from changing
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question which statement about buffers is true? select all that apply b…
A. Buffers neutralize solutions donating hydrogen ions or accepting hydrogen ions. C. Buffers help maintain homeostasis. D. Buffers prevent large changes in pH.
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drag and match match the following bonds to their correct descriptions.…
Nonpolar covalent bonds: Equal sharing of electrons between atoms Hydrogen bonds: Water molecules are attracted to each other by this type of bond Polar covalent bonds: An unequal…
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poetry of langston hughes quiz complete 1 3 8 10 in what way are the li…
The poem uses repetition to create meaning
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question dissolved ions that can conduct an electrical current in a sol…
B. electrolytes
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question 7 a solution that dissociates to release hydrogen ions into so…
A. an acid
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drag and match determine the correct description of each type of soluti…
Solution: A uniform mixture of a solvent and a solute Colloid: A solution with dispersed proteins that will not settle Suspension: A solution with large particles that will settle…
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question which of the given solutions is the most acidic? answer a solu…
B. A solution with a pH of 2
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how many hydrogen atoms are in one molecule of water? 2 hydrogen 3 hydr…
2 hydrogen
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question when table salt is put into a glass of water, it dissolves. th…
dissociation or ionization
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how many oxygen atom(s) are in one molecule of water? 3 oxygen 1 oxygen…
B. 1 oxygen
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question which properties of water make it stick to your hand and get i…
B. Polarity, C. Hydrophilic
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question chemicals that must be in our diet in order for the body to fu…
B. nutrients
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what is the charge distribution in a water molecule? hydrogen is positi…
Hydrogen is positively charged, and oxygen is negatively charged.
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what is a solution? a mixture of two or more substances in which the mo…
A mixture of two or more substances in which the molecules of the substances are evenly distributed.
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question 1 a chemical that can release free hydroxide ions or accept fr…
base
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question the major difference between inorganic and organic compounds i…
not composed of carbon and hydrogen
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gasoline at room temperature does not combust. how can one increase the…
B. Lower the energy of activation by creating a spark.
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if oxygen has an atomic weight of 16, what is the molecular weight of a…
A. 32
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question the chemical properties of every element are determined by ans…
the number and arrangement of electrons in the outer energy level
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drag and match certain bonds are formed based on the attraction of the …
Ion: A charged atom Cation: Positively charged atom due to losing an electron Anion: Negatively charged atom due to gaining an electron
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what is the primary mechanism through which freshwater mussels reduce t…
By actively filtering and removing suspended particles from the water
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drag and match determine the type of energy the following molecules or …
Combustion of gasoline to make the car move: Energy in motion, Kinetic energy Gasoline: Energy stored in matter, Potential energy Generating energy for muscle movement: Energy sto…
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question the unequal sharing of electrons in a molecule of water is an …
B. a polar covalent bond
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to the right of the arrow in the reaction below, what is oxygen (o2)? 6…
product
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question ① compounds are formed when two or more different elements bin…
Glucose, Water
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in a chemical reaction, on which side of the arrow do the reactants (th…
A. left
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question which of the following statements is correct? answer because o…
An anion is a negatively charged atom or group of atoms.
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refer to the slide show above, test tube 2. why did the water level in …
The atoms of Na and Cl occupied the spaces between the water molecules.
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question 1 select which of the following are isotopes of hydrogen. sele…
B. Hydrogen atom with different number of neutrons C. Tritium D. Deuterium
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multiple choice question which one of these is defined as a chemical or…
B. Buffer
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a solution with a ph of 7 is ________. basic reason: the terms \basic\ …
neutral
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question the symbol h₂o means that each molecule of water is composed o…
B. two hydrogen atoms and one oxygen atom
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during a chemical reaction, which of the following does the arrow stand…
C. yields
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multiple choice question a solution with a ph of 7 is o basic o alkalin…
C. neutral