Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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8. some farmers store animal droppings in containers and capture natura…
methane
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5. thymine and adenine form a base pair in the dna molecule. these two …
D. The diagram showing correct hydrogen bonding between thymine (left) and adenine (right) via two hydrogen bonds, with proper donor-acceptor interactions.
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(a) the c-f is easier to break than the c-h bond. (b) the c-f is more p…
B. \( \text{Na}^+ \) ### Second Question (Boiling Point of Hydrocarbons)
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1. | compound name | structural formula | molar mass (g/mol) | | ---- |…
D. Propanoic acid, because it can form intermolecular hydrogen bonds ### Second Question (Nonane vs 2,3,4 - trifluoropentane Boiling Point) (Note: The question seems cut off, but …
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3. pharmaceutical drug diversion schemes generally involve: a. all pres…
3. d. controlled substances 4. a. motorized wheelchairs and scooters
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who was johannes kepler, and why is he known today? (5 points) he was a…
He was a German astronomer who figured out that planets orbit in ellipses, not perfect circles.
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summarize what you have studied if a substance is ionic, then it likely…
conduct electricity when dissolved in water (or melted), and have a high melting/boiling point
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calcium oxide (cao) is ✓ ionic complete what properties would you expec…
- It is likely soluble in water. - It will likely light up a bulb in a conductivity apparatus. - It will likely have a high melting point.
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spoon beaker stirring rod graduated cylinder distilled water in spray b…
Spoon, Beaker, Stirring Rod, Graduated Cylinder
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exercise 6th february, 2020 1. state the three main type of salt and ex…
1. Acidic Salt - Example: $\ce{NaHSO_4}$ 2. Basic Salt - Example: $\ce{Ca(OH)Cl}$ 3. Neutral Salt - Example: $\ce{NaCl}$ ### Sub - Question 2: State any 4 properties of salt
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the term used to describe atoms chemically joined together is... select…
d. bonded.
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what is the correct ratio of the atoms of the two elements present in a…
1. c. 1:2 2. b. 2 hydrogen atoms
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a shorthand that uses chemical symbols and subscripts to represent the …
1. c. formula. 2. a. 3
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in the compound represented by the chemical formula nh₄cl there would b…
1. d. 1 nitrogen atom. 2. a. A
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bonding in which atoms share electrons is called... select one: a. bina…
b. covalent bonding.
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consider the possible bonding of the atom shown below. the atom would p…
a. lose an electron.
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analyze how the conductivity test worked how does a conductivity appara…
Ions complete the flow of electrons to form a circuit.
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which of the following elements is correctly matched with the number of…
c. Chlorine (Cl) .. 1
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which of the following statements about the valence electrons is false?…
First question: d. Valence electrons are found in the nucleus. Second question: c. II and IV
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select one: a. i and ii b. ii and iii c. ii and iv d. iii and iv which …
d. III and IV --- ### Second Question (Diatomic Molecule)
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which of the following models represents a positive ion? a: 11 protons …
a. A
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when atoms bond by gaining or losing electrons, what kind of bond is fo…
d. Ionic bond
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sulfur has 16 electrons. after it bonds with magnesium it acquires a 2-…
1. d. 18 2. a. BeO
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lab: ionic and covalent bonds assignment: reflect on the lab active det…
No, the hypothesis is not completely supported. There are key exceptions: some polar covalent substances dissolve in water and conduct electricity in solution, and some ionic subs…
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when magnesium combines with chlorine, it loses 2 electrons. what is th…
1. a. +2 2. a. oppositely charged ions attract.
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which of the following will become a negative ion when it bonds with an…
a. A
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one calcium atom (ca⁺²) will combine with which of the following atoms …
b. O⁻²
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when the atom pictured below is entering into a chemical bond, it has a…
c. gain electrons.
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when a fluorine atom gains an electron from a lithium atom and the stab…
1. d. ionic. 2. c. C
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which of the following elements will form an ionic bond with the elemen…
1. b. B 2. c. +1
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which of the following statements about an oxidation number is false? s…
1. c. An oxidation number is equal to the number of electrons found in an atom of the element. 2. b. -1
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seleniums oxidation number is -2. to become stable it must... select on…
1. a. lose 2 electrons 2. d. $\text{Na}_2\text{S}$
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the correct name for the compound that has the formula bacl₂ is... sele…
1. b. Barium chloride. 2. d. $\text{CaI}_2$
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which of the following is the correct formula for the compound formed b…
1. a. $\text{ScCl}_3$ 2. c. potassium oxide
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the oxidation numbers in a compound always add up to... select one: a. …
1. d. 0 2. b. -1
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in the compound mgo, what is the oxidation number of oxygen? select one…
1. d. -2 2. d. Polyatomic ions do not combine with ions of the opposite charge to form chemical compounds
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when the polyatomic ion (so₄)²⁻ combines with the iron (iii) ion, fe³⁺,…
1. c. $\text{Fe}_2(\text{SO}_4)_3$ 2. b. sodium carbonate
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which of the following isotopes should be expected to be radioactive? (…
d. D ($_{94}^{244}\text{Pu}$)
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atoms of the same element that have different mass numbers are called..…
a. isotopes.
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what kind of nuclear radiation consists of the most massive and slowest…
1. c. Alpha 2. c. Physical
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hydrogen and oxygen combine to form water. this is an example of what t…
1. b. Chemical 2. d. a nuclear change.
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when placed in a cloud chamber, a radioactive substance does which of t…
1. a. Leaves a trail of condensed water vapor. 2. b. nuclear fission.
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which of the following statements about the normal operation of nuclear…
1. b. A small amount of fuel produces a large amount of energy. 2. c. Fossil B contains more carbon-14 than fossil A does.
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a certain volume of water contains 100,000 hydrogen atoms and 50,000 ox…
8000000
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73 of 74 concepts completed assignment is past due fill in the blank qu…
phase diagram
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complete the sentence with the correct comparative or superlative adver…
worst
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the added sugar content in a serving of this cereal is minimal (< 1g). …
Apple juice concentrate
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a popular breakfast cereal has a claim on the front panel of the box, w…
d. nutrient claim
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exercise 1. state the three main type of salt and example each 2. state…
1. Acidic Salt - Example: $\ce{NaHSO4}$ 2. Basic Salt - Example: $\ce{Ca(OH)Cl}$ 3. Neutral Salt - Example: $\ce{NaCl}$ ### Sub - Question 2: State any 4 properties of salt
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which statement best describes the rhyme scheme in \a psalm of life\? t…
D. Each stanza adheres to its own rhyme scheme (ABAB, CDCD, EFEF, etc.).
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which statement best describes the rhyme scheme of \a thought on the in…
There are two stanzas with the rhyme scheme ABCB throughout.
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which statement best describes the rhyme schemes of \the author to her …
Bradstreet uses couplets for their overall rhyme scheme and structure; Wheatley uses couplets to enhance the poem as a song of praise for creation.
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match the type of intermolecular force with the description of where it…
To solve this, we analyze each intermolecular force: ### Dipole - Dipole Forces These act between polar molecules (molecules with permanent dipoles, i.e., partial positive and par…
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question 13 1 point which otc product is used to provide temporary reli…
1. B. Cough suppressant 2. B. Aspirin
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5. convert 2.50 x 10⁷ ng into cg. 6. convert 9.7 x 10⁻⁶ kj into mj. 7. …
5. $2.50 \times 10^2\ \text{cg}$ 6. $9.7\ \text{mJ}$ 7. $\approx 8.28\ \text{kL}$ (rounded to 3 significant figures) 8. $\approx 0.20\ \text{km}$ (rounded to 2 significant figures…
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if 14.0 grams of co₂ are removed from the lunar module air, how many mo…
\( 1.91 \times 10^{23} \) molecules (Option: 1.91 x 10^23 molecules)
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ground control reports that 38.5 grams of lioh have been used in the sc…
59.48 grams
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environmental sensors detect 3.42 grams of h₂o inside the lunar module.…
\(0.380\) Moles
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label the following diagram with the correct phase changes. drag the la…
- Water → Vapor (up): Evaporation - Vapor → Water (down): Condensation - Water → Ice (down): Freezing - Ice → Water (up): Melting - Ice → Vapor (left curve): Sublimation - Vapor →…
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which of the following changes in state require energy to occur? which …
- Energy is required: Melting, Evaporation, Sublimation - Energy is released: Freezing, Condensation, Deposition
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ground control predicts that 0.426 moles of co₂ will accumulate in the …
20.41 grams (Option: 20.41 grams)
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when the explosion occurred, the o₂ tank lost 145,000 g of o₂ and power…
4530 Moles (the option: 4530 Moles)
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multiple choice question which group of elements commonly forms ions th…
Be, Mg, Ca, Sr, Ba
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multiple select question select all that apply which statements describ…
- The sum of the oxidation number of each ion multiplied by the number of ions in a formula unit must equal zero. - If no subscript is written, it is assumed to be one. - Subscrip…
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multiple choice question what term describes a one - atom ion, such as …
A. monatomic ion
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fill in the blank question the chemical formula for an ionic compound, …
empirical formula
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multiple choice question for an element in an ionic compound, the numbe…
A. oxidation
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multiple select question select all that apply which statements about f…
- The overall charge of a formula unit is zero. - The chemical formula for an ionic compound represents a formula unit. - The formula unit represents the simplest ratio of the ion…
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multiple choice question most transition metals and group 13 and 14 met…
more than one possible ionic charge
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fill in the blank question a one - atom ion is called a(n) □ ion.
monatomic
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multiple choice question what is the term for the chemical formula for …
a formula unit
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fill in the blank question a formula unit represents the simplest of th…
ratio
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wilhelm conrad roentgen discovered x - ray by: observing an x - ray pro…
A. observing as X - ray produced with high voltage (assuming the first option is A, adjust the identifier based on actual numbering) ### Question 2 (Thomas Edison contributed grea…
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. $\boldsymbol{2F_2(g) + O_2(g) ightarrow 2OF_2(g)}$
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \( \ce{2 F2(g) + O2(g) → 2 OF2(g)} \)
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complete the table below. for example, in the first row decide whether …
To solve for the most likely ions, we analyze each element based on its position in the periodic table and typical ion formation: ### Chlorine (Cl) - **Step 1: Determine ion type*…
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fill in the missing information: | symbol | atom or ion? check all that…
| symbol | atom or ion? (check all that apply) | number of protons | number of electrons | |--------|--------------------------------------|-------------------|-------------------…
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add or subtract the following measurements. be sure each answer you ent…
First: \( 14.50 \, \text{mL} \) Second: \( 16.1 \, \text{mL} \) Third: \( 0.7 \, \text{mL} \)
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the redox reaction given below occurs in a basic solution. \\(\\ce{hpo^…
The number of electrons transferred in the $\ce{HPO_3^{2 - }}$ half - reaction is 2. The balanced half - reaction is $\ce{2e^- + 2H_2O + HPO_3^{2 - } = H_2PO_2^- + 3OH^-}$ (the nu…
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select the correct answer from each drop - down menu. a potassium ion c…
To solve this, we analyze ionic and covalent bonding in potassium compounds: ### For the first drop - down (compound with both ionic and covalent bonds): A compound like $\ce{KNO3…
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2al + 3sn²⁺ → 2al³⁺ + 3sn in the voltaic cell above, which letter repre…
C
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3cu²⁺ + 2cr → 2cr³⁺ + 3cu in the voltaic cell above, which letter repre…
D
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consider the redox reaction below. ag⁺(aq) + zn(s) → zn²⁺(aq) + ag(s) b…
The balanced silver half - reaction is \(Ag^+(aq)+e^-\to Ag(s)\), and the number of electrons transferred is 1.
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the $e_{\\text{cell}}^{\\circ}$ value for the cell is -0.55 v. calculat…
+106 (or more precisely +106.13 or +106.15, but typically rounded to a reasonable number of significant figures. The given $E^\circ_{cell}$ has two significant figures? Wait, $E^\…
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calculate the $\\mathrm{e^\\circ_{cell}}$ for the cell given below. $\\…
\(-0.55\)
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calculate the gibbs free energy for the cell. the cell has a potential …
-376 (or -376.3, depending on rounding; the exact calculation gives -376291.5 J = -376.2915 kJ, so approximately -376 kJ)
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calculate the e⁰_cell value for the cell. 2fe³⁺ + mn → mn²⁺ + 2fe²⁺ hal…
\(+1.95\)
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a current of 5.25 a is applied to the aluminum sulfate solution for 112…
\boxed{3.29} (or more accurately, let's recalculate: Wait, maybe I made a mistake in the number of electrons. Wait, Al³+ gains 3 electrons, so 3 moles of e⁻ per 1 mole of Al. So t…
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aluminum plating is sometimes used to reduce corrosion in materials exp…
3
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how many minutes will it take to plate the spoon with 0.25 g silver? $\…
\boxed{0.93} (Wait, no, wait, let's check again. Wait, 0.25 g Ag: moles = 0.25 / 107.87 ≈ 0.002317 mol. Q = 0.002317 mol * 96485 C/mol ≈ 223.6 C. t = 223.6 / 4 = 55.9 s ≈ 0.93 min…
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how many minutes will it take to plate the spoon with 10.3 g cr? cr³⁺ +…
\( \approx 103 \) (or more precisely, around 102.8) minutes.
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what is the ecell for the electrolysis of molten mni₂(l)? half-reaction…
-1.72 V (corresponding to the option: -1.72 V)
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what is the balanced net ionic equation for the electrolysis of molten …
A. \(MnI_2(l) ightarrow Mn(s)+I_2(s)\)
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knowing that h₂ is produced during reduction and o₂ is produced during …
\(-2.06\ V\) (corresponding to the option - 2.06 V)
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knowing that h₂ is produced during reduction and o₂ is produced during …
\(4H_2O ightarrow 4OH^-+2H_2+O_2 + 4H^+\) (the option with this equation)
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what occurs during oxidation in the reaction for the electrolysis of 1.…
Oxygen gas is produced.
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what occurs during reduction in the reaction for the electrolysis of 1.…
D. Hydrogen gas is produced.
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what product forms at the anode when molten nibr₂ goes through electrol…
\(Br_2\) (the option: \(Br_2\))
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what reaction takes place at the cathode when molten nibr₂ goes through…
D. \( \ce{Ni^{2+} + 2e^- \to Ni} \)
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what product forms at the cathode when cucl₂ goes through electrolysis?…
D. Cu (assuming the options are labeled as A. $\ce{Cu^{2+}}$, B. $\ce{Cl^{-}}$, C. $\ce{Cl_{2}}$, D. $\ce{Cu}$)