Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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what type of bond is formed between a metal and a nonmetal? * 5 points …
1. B. Ionic 2. A. CaCl2
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which of the following compounds contains a covalent bond? * 5 points n…
1. C. $NH_3$ 2. B. $CO_2$ - Covalent bond - Carbon dioxide
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how many valence electrons does an atom need to satisfy the octet rule?…
8
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covalent bonds involve the... * 5 points single electron shared electro…
1. C. Sharing of electrons 2. A. KBr
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the bond in hf is best described as: * 5 points nonpolar covalent polar…
Polar covalent
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3. if you have a sample of atoms and each atom has 12 protons in its nu…
Magnesium
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question 1 of 10. which sentence describes a poems meter? a. the thunde…
D. There are 14 syllables in each line.
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traditional poetry has definite rhyme schemes, precise rhythms, and cle…
There is no one - size - fits - all answer. Poets may choose to follow rules to honor tradition and use established forms effectively, or they may break them to innovate and expre…
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13. other than using a catalyst, how can a reaction be sped up? 14. whi…
d. $C_5H_{10}O_5$
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14. which of the following is a carbohydrate? a. nh₃ b. co₂ c. c₂h₄o d.…
d. $C_5H_{10}O_5$
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exam: hand hygiene basics 1. when would alcohol - based hand rubs (abhr…
1. After contact with chemical substances 2. Before applying AND after removing the gloves 3. False
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87. consider the three flasks in the diagram below. assuming the connec…
The partial pressure of He is $6.67\ kPa$, the partial pressure of Ne is $10.13\ kPa$, the partial pressure of Ar is $12.0\ kPa$, and the total pressure is $28.8\ kPa$.
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85. consider the flasks in the following diagram. what are the fi- nal …
The final partial - pressure of $H_2$ is approximately 317 torr, the final partial - pressure of $N_2$ is approximately 50.7 torr and the total pressure is 368 torr.
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partial pressure 81. determine the partial pressure of each gas as show…
$P_{He}\approx0.44$ atm, $P_{Ne}\approx0.33$ atm, $P_{Ar}\approx0.22$ atm
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in the chemical equation hcl + caco₃ → ___, which of the following elem…
C. Nitrogen
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name: louis park jhs chemistry department podcast #4 - beryllium: the m…
1. C 2. C 3. E 4. B 5. A 6. F 7. H 8. G
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a tiny sample of an aqueous solution of two substances r and p is sketc…
Number of $R$ molecules: 4 Number of $P$ molecules: 8
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a tiny sample of an aqueous solution of two substances r and p is sketc…
Number of $R$ molecules: 4 Number of $P$ molecules: 8
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draw the lewis structure for the becl4^2 - ion. predict its geometry an…
Lewis structure: Be in the center with four single bonds to Cl atoms, each Cl has 3 lone - pairs and Be has a formal charge of - 2. Geometry: Tetrahedral. Hybridization of Be: \(s…
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part 2 of 3 select the single best geometry of becl4^2 - ion. tetrahedr…
Part 2 of 3: A. Tetrahedral Part 3 of 3: $sp^3$
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ammonia has been studied as an alternative \clean\ fuel for internal co…
0.35
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draw the lewis structure for n₂cl₂ molecule. be sure to include all lon…
The Lewis structure has a double - bond between the two N atoms (\(N=N\)), with a Cl atom single - bonded to each N atom (\(Cl - N=N - Cl\)). Each Cl atom has 3 lone pairs of elec…
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which of the following is not human - caused groundwater pollution? a) …
For the first question: B. Water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. For the second question: B. Sandstone
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question 17 using the rule of 13, what is a possible formula for m=120 …
all of the above are possible molecular formulas
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all of the following are major components of soil except a) organic mat…
For the first question: C. carbonic acid For the second question: B. It has been moved from another location.
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given this table of electronegativities: atom electronegativity h 2.2 c…
$H_2S<HI<NH_3<H_2O$
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question 15 0.5 pts a molecule has with the formula cₙh₂ₙ₊₂ will have t…
$C_nH_{2n+1}Cl$
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identify the substances that contain discrete molecules. check all that…
A. $CH_4$ C. $BF_3$
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classify the following substances as an ionic compound or a covalent co…
CH₄: covalent RbCl: ionic BF₃: covalent BaCl₂: ionic SrO: ionic
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list the following bonds in order of increasing ionic character: the ba…
$H - S<Cl - F<Ba - S<Li - F$
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draw the lewis dot symbols for the following atoms/ions. part 1 of 2 na…
Na: Na• O²⁻: [ :O: ]²⁻ (with 4 pairs of dots around O)
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miley cyrus always studied her spelling words so she would earn a gold …
Question 1: This is an example of positive reinforcement. Question 13: the extra chemical molecules are sucked back into the neuron in a process called reuptake.
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for the following groups of elements, arrange elements in increasing or…
Part 1: Cs < Rb < K Part 2: I < Br < Cl Part 3: Ba < Na < Si < P
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arrange the following elements in order of increasing first ionization …
Cs - 1, Na - 2, Al - 3, S - 4, Cl - 5
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list the following ions in order of increasing ionic radius: br⁻, rb⁺, …
$Sr^{2+}<Rb^+<Br^-<Se^{2-}<As^{3-}$
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drag the correct words to complete the sentence. the tempo scheme of th…
slow
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which statement is true of ph buffers? (a) they consist of strong acids…
Part A: C. They consist of weak acids and weak bases. Part B: B. $A^-$ reacts with $H^+$ to become HA.
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buffers work best when... the ph is nearly neutral. nearly all of the b…
For the first question: about half of the buffer molecules are dissociated. For the second question: It's the same reaction running backward or forward.
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which statement must be mentioned in explaining why amphipathic molecul…
Part A: Nonpolar groups repel water. Part B: a mingling of molecules and/or ions.
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water has surface tension because... - molecules at the surface make mo…
First question: hydrogen bonds between surface water molecules resist being stretched. Second question: (a) A water molecule can make 4 hydrogen bonds.
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which factor is important in making it possible to cool yourself by swe…
Part (a): D. Both (a) and (b) Part (b): it takes energy to break hydrogen bonds.
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part e if you want a molecule that is highly polar, look for one that c…
H - N
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dr. harden says the o - o bond is polar and the c - c bond is non - pol…
First - part: Wrong again, Hugh. Both bonds are nonpolar. Second - part: OH
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match the words in the left column to the appropriate blanks in the sen…
1. acidic 2. neutral 3. basic 4. \(H^+\) 5. \(OH^-\) 6. buffer
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part e water is sometimes called the \universal solvent.\ is that accur…
For the most part. Water readily dissolves most substances, but not hydrophobic ones.
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which best describes how charges are distributed on a water molecule? t…
The oxygen end is negative relative to the end with the two hydrogen atoms. Water is highly cohesive. Its molecules tend to resist increases in their motion. When water is heated,…
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how does the ph of the solution on the right compare with that of the s…
The solution on the right is basic relative to the solution on the left.
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in a neutral solution the concentration of ______. hydrogen ions is gre…
C. hydrogen ions is equal to the concentration of hydroxide ions
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what is the arrow pointing to? electron hydronium ion hydrogen ion hydr…
B. hydronium ion
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about ______ molecules in a glass of water are dissociated. 1 in 5,000,…
E. 1 in 500,000,000
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part e what is the charge on a hydronium ion? 2- 0 1+ 2+ 1- submit requ…
Part E: C. 1+ Part F: B. 1-
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which of these is the correct equation for the dissociation of water? h…
For the dissociation of water: A. H₂O + H₂O <==> H₃O⁺ + OH⁻ For the charge on a hydronium ion: +1 (not shown as an option in the provided choices for the charge question, but it s…
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how did this molecule form? a hydrogen molecule bonded with an oh- mole…
C. A water molecule gained an hydrogen ion from another water molecule.
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what name is given to this molecule? hydronium ion hydroxide ion glucos…
A. hydronium ion
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part a the simplest unit of matter that still retains the properties of…
D. an atom
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what is the term for an atom that is electrically charged as a result o…
C. ion
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carbon-12 and carbon-13 are different in the number of ____________ the…
B. neutrons
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vocabulary: which chemical bonds hold atoms together? a chemical bond i…
1. ionic 2. ions 3. covalent 4. single 5. double 6. polar 7. nonpolar 8. hydrogen
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a phrase that applies to covalent bonding and not other kinds of bonds …
A. electron - sharing
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which model most accurately represents the current view of the structur…
1. B. Probability model 2. B. protons
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an atom has 8 protons, 8 neutrons, and 8 electrons. another isotope of …
1. 10 neutrons 2. an atom has too many neutrons
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two atoms always represent the same element if they have ... - the same…
First question: the same number of protons. Second question: C; it has 6 protons.
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which statement is true of the atom shown in the diagram? an electron w…
D. All of the above
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dr. jones says an atom has 3 electrons in the first shell and four elec…
First part: the first shell shouldn't have 3 electrons. Second part: The valence shell has higher energy than other occupied shells.
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dr. jones says an atom has 3 electrons in the first shell and four elec…
All of the above.
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part c an ionic bond involves ______. no atoms other than sodium and ch…
an attraction between ions of opposite charge
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atoms with the same number of protons but with different electrical cha…
Part A: E. are different ions Part B: C. ionic
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for the following molecule, what will be the percentages of the m, m+2,…
100%, 75%, 25%
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question 16 the following molecule has how many degrees of unsaturation…
5
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8. how long does it take for approximately 75% of carbon - 14 to decay …
11460 years
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complete the following table regarding acids and bases. | | acids | bas…
| | Acids | Bases | |--|--|--| | Effect on $H^+$ when dissolved in $H_2O$ | Increase $H^+$ concentration | Decrease $H^+$ concentration | | pH range | $pH < 7$ | $pH>7$ | | Exampl…
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percy likes to drink hot tea, and his friend likes to drink cold tea. p…
Does white sugar dissolve more quickly in warm water or in cold water? Does white sugar dissolve in warm water more quickly than brown sugar does?
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bismuth - 210 is an isotope that radioactively decays by about 13% each…
$104.85$
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2. oils are nonpolar substances (molecules formed by nonpolar covalent …
Oils are non - polar and have no favorable interactions with polar water. NaCl is ionic, and its ions are attracted to water through ion - dipole interactions.
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15. you add a negatively charged substance to the water molecules shown…
The negatively charged substance would orient itself such that it is attracted to the slightly positive hydrogen atoms of the water molecules.
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14. in the following chemical equation, identify the products and react…
Reactants: $6CO_2$ and $6H_2O$. Products: $C_6H_{12}O_6$ and $6O_2$. The equation is balanced.
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13. are transformations of matter that result in new substances being m…
Chemical reactions
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nh₄cl, an expectorant spell out the full name of the compound. part d s…
Ammonium chloride Strontium nitrate Potassium nitrite
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part a zn(c₂h₃o₂)₂, a cold remedy spell out the full name of the compou…
Part A: Zinc acetate Part B: Magnesium nitrate
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chapter 2: essential chemistry for biology 12. complete the diagram ill…
Under Atom Y: $Y^{-}$ Under Atom X: $X^{2 + }$ Under Atom Y: $Y^{-}$
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enter the correct formula for the following compounds. part a zinc chlo…
$Zn(ClO_{3})_{2}$
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copper(i) sulfate express your answer as a chemical formula. a chemical…
$Cu_2SO_4$
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read the excerpt from act 1, scene 3, of julius caesar. cassius. and wh…
Cassius portrays Caesar as a cruel - hearted tyrant, and at the same time says he pities Caesar because Caesar can't help himself.
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part c magnesium bicarbonate express your answer as a chemical formula.…
Part C: $Mg(HCO_3)_2$ Part D: $KNO_2$
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zinc chlorate express your answer as a chemical formula. a chemical rea…
Part A: $Zn(ClO_{3})_{2}$ Part B: $(NH_{4})_{2}O$
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consider the molecule f₂. part: 0 / 2 part 1 of 2 draw the mo diagram f…
Follow the steps above to draw the MO diagram for F₂ with 18 electrons filled in the molecular orbitals in the correct order of energy.
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6 multiple choice 1 point if an irritating chemical has splashed in you…
6. flood the eye with running water from the most convenient source immediately. 7. the steps for responding to a fire.
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draw a possible resonance structure for the bromate ion (bro₃⁻) with mi…
Draw a structure with Br as the central atom. Connect two oxygen atoms to Br with single - bonds and one oxygen atom to Br with a double - bond. Place 3 lone - pairs on each of th…
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question 16 0.5 pts a molecule has with the formula c_nh_2n+3n will hav…
$C_{n}H_{2n+2}O$
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she experimented with other fluids at home, she also asked her sons che…
B. comma splice
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chapter 14 review 10. a common kind of mechanical weathering is called …
10. b. ice wedging 11. b. acid rain 12. d. jointing 13. d. hot, wet climates 14. c. the parent material 15. a. thick 16. d. irrigation 17. b. a mudflow 18. c. abrasion 19. c. diff…
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0.235 g ti, 0.298 g f₂ express the mass in grams to three significant f…
$0.608$ g
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draw lewis structure for nh₄⁺, showing formal charges.
The Lewis structure of $NH_{4}^{+}$ has a nitrogen atom in the center bonded to four hydrogen atoms with single bonds. The formal charge on the nitrogen atom is + 1 and the formal…
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consider the reaction: zno(s) + h2o(l) → zn(oh)2(aq) given an initial m…
19.64 g
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decide whether each molecule or polyatomic ion is polar or nonpolar. if…
| molecule or polyatomic ion | polar or nonpolar? | atom closest to negative side | | ---- | ---- | ---- | | NH₃ | polar | N | | F₂ | nonpolar | | | OCS | polar | O |
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what is the hybridization of the central atom in the orthosilicate (sio…
$sp^{3}$
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answer the questions below about the highlighted atom in this lewis str…
In how many sigma bonds does the highlighted atom participate? 4 In how many pi bonds does the highlighted atom participate? 0 What is the orbital hybridization of the highlighted…
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answer the questions in the table below about the shape of the phosphor…
How many electron groups are around the central phosphorus atom? 4 What phrase best describes the arrangement of these electron groups around the central phosphorus atom? Tetrahed…
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answer the questions in the table below about the shape of the sulfur h…
What word or two - word phrase best describes the shape of the $SBr_6$ molecule? Octahedral What is the angle between the sulfur - bromine bonds? 90
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what is the hybridization of the central atom in the methane (ch₄) mole…
$sp^3$