Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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chemical splashes in the eye should be rinsed a minimum of select minut…
20 (from the select options, the correct choice is the option with "20")
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toxic chemicals can be poured down the drain if you run plenty of water…
b. False
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lesson 31b - specific heat capacity round to two significant figures. y…
1. 42 K 2. 4.184 J/g·K 3. 4400 J 4. 1.1 Calories
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what is required to determine the amount of heat required to heat up 2.…
mass, change in temperature, specific heat capacity of platinum
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which of these stanzas is in blank verse? \let us go then, you and i, w…
no rhyme, ten syllables to a line, and pairs of syllables in which the second syllable is stressed
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lesson 31b - specific heat capacity round to two significant figures. y…
1. 93 K 2. 0.129 J/g·K 3. 560 J 4. 0.13 Cal
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health care professionals who are overexposed to select hazards are at …
radiation
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order the following in the order of increasing energy required to heat …
Gold < Platinum < Lead < Cadmium < Silver < Copper < Zinc < Nickel < Chromium = Iron < Calcium < Silicon < Carbon < Aluminum < Neon < Water
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currently, new regulations control the use of pesticides and chemical f…
Water contamination
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which of the following is matched correctly in the equation $q = mc_p\\…
q = heat, Cp = specific heat capacity, ΔT = change in temperature, m = mass
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this is a form of ground water pollution where heavier chemicals fall b…
B. Deposition
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lesson 31a - energy unit convert. 430 cal = \\boxed{} kj
1799.12
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lesson 31a - energy unit convert. 700 kj = cal
167304
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lesson 31a - energy unit convert. 8.5 kj = \\boxed{} cal
2.03 (or 2.0, depending on rounding convention)
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lesson 31a - energy unit convers convert. 8.5 kj = \\boxed{} cal
2.0315
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lesson 31a - energy unit conversio convert 966 cal = \\boxed{} j
4041744
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composition of air nitrogen - 78% oxygen - 20.9% other gases - >0.17% a…
D. nitrogen
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arrange in order of increasing abundance (from least to most). composit…
carbon dioxide, other gases, argon, oxygen, nitrogen
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perform the following temperature conversions. use appropriate signi to…
348.15 16.85 297.15 29.44 53.6 213.8 23.89 290.93 116.33 275.37 76.73
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for years, biologists have experimented with using grime - eating bacte…
B. In many cases,
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which element would be most electronegative? * a. k b. na c. br d. f id…
D. F ### Second Question (Identify the mystery element):
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how many valence electrons does oxygen have? * 1 point a. 2 b. 4 c. 6 d…
C. 6 ### Second Question (Mystery Element)
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metalloids are found: * a. far left side b. far right side c. randomly …
D. Along the zig - zag staircase ### Second Question (Family with 1+ ions)
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3. draw all possible resonance structures for each of these compounds. …
a. SO₂: 2 resonance structures; formal charges: S=0, one O=0, one O=-1 per structure; bond order=1.5 b. NO₃⁻: 3 resonance structures; formal charges: N=+1, one O=0, two O=-1 per s…
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the 2022 nobel prize in chemistry was awarded to three pioneers in the …
A. Stanford;
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lesson 25 - different forms of energy why is the energy in food conside…
chemical bonds in food store energy
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question 2. select the correct answers from the drop-down menu for each…
a) lower b) higher
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which statements correctly describe the properties of air? select three…
- Air pressure is created by the weight of the atmosphere pushing on Earth's surface. - Denser air is heavier than less dense air. - Air is less dense at higher altitudes.
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7. the bond angle in cl₂o is expected to be approximately 120°. 180°. 1…
The option with 115° (the fourth option in the list)
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question 7 7. the bond angle in cl₂o is expected to be approximately 12…
110°
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lesson 24: systems and energy during a chemical or physical change, the…
remains the same
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lesson 24: systems and energy which of the following is due to a flow o…
All of the options (chemical changes, phase changes, chemical reactions, freezing) are due to a flow of energy.
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lesson 24: systems and energy which of the following is true about the …
the total energy remains the same; the reaction is exothermic
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lesson 24: systems and energy which of the following is true about the …
the reaction is endothermic, the system becomes warmer
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read the text. you have probably heard of the ph scale, which measures …
- Hydronium ions form in the solution: The solution becomes more acidic. - Hydroxide ions form in the solution: The solution becomes more basic.
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30. how much energy (heat) is required to convert 52.0 g of ice at -10.…
157.8 kJ (closest option)
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lesson 24: systems and energy you walk into a room and you start to fee…
an exothermic process is occurring, you are losing heat
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lesson 24: systems and energy which of the following are exothermic pro…
liquid to solid, gas to liquid
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lesson 24: systems and energy which of the following processes occur wh…
liquid to solid, Gas turns into liquid
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how many grams of cl are in a 38.0-g sample of the chlorofluorocarbon c…
13.1
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how many grams of cl are in a 38.0-g sample of the chlorofluorocarbon c…
21.6
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how many grams of cl are in a 38.0-g sample of the chlorofluorocarbon c…
22.3 g 29.4 g
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determine the mass of oxygen in a 7.20-g sample of al₂(so₄)₃. express y…
4.04 g O 55.4 g Fe
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determine the mass of oxygen in a 5.8-g sample of sodium bicarbonate (n…
3.3 g O
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1.74 kmol sulfur trioxide m_{so_3} = g
139321.8
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1.02 mmol carbon disulfide m_{cs_2} = g submit request answer
0.0777
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answer the following questions. 33. explain why an atom with a high ion…
- **33**: A high ionization - energy value means a large amount of energy is needed to remove an electron. Since forming a positive ion requires losing an electron, an atom with h…
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0.615 mol magnesium fluoride m_mgf₂ = g
38.3
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part a 1.28 mol carbon tetrafluoride m_cf₄ = g
112.65
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19. drag the processes from the column on the left to the correct class…
- Physical Processes: Freeze - Thaw, Heat Expansion, Deposition, Wind Erosion - Chemical Processes: Carbonic Acid, Limestone Hydrolysis, Weak Acidification, Dissolution ### Questi…
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question 10 0.5 pts given the following data, determine the enthalpy of…
-603 (rounded to the correct significant figures)
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using enthalpies of formation, determine the balanced thermal chemical …
-13.07
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using enthalpies of formation, determine the enthalpy of the following …
s: First reaction enthalpy: $\boldsymbol{-6535}$ Second reaction heat: $\boldsymbol{-117.0}$
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using bond dissociation energies, determine the approximate enthalpy of…
(First Problem: Approximate, assuming BDE values) -1994 (or -2000, but based on calculation with given O2=7, though unbalanced, but following problem’s numbers)
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using bond dissociation energies, determine the approximate enthalpy of…
-986
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etylene, c₂h₄, reacts with hydrogen to produce methane, ch₄. c₂h₄ (g) +…
# Explanation: ## Step1: Identify Target Reaction Target: $\ce{C2H4(g) + 2 H2(g) -> 2 CH4(g)}$ ## Step2: Manipulate Given Reactions 1. Reaction 1: $\ce{2 C2H6(g) + 7 O2(g) -> 4 CO…
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etylene, c₂h₄, reacts with hydrogen to produce methane, ch₄. c₂h₄ (g) +…
### First Sub - Question (Using Hess's Law) # Explanation: ## Step 1: List the target reaction and given reactions Target reaction: $\ce{C2H4 (g) + 2 H2 (g) -> 2 CH4 (g)}$ Given r…
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strontium oxide reacts with liquid water to produce strontium hydroxide…
s: Question 1: \(-132\) Question 2: \(-1743\)
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student activity: energy tracker observation log instructions: as you w…
1. When WALL - E was chasing the red light, the space ship's potential energy was converted into kinetic energy as it moved. 2. The Axiom spaceship uses electrical energy to move …
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freezing point depression, boiling point elevation, and osmotic pressur…
True
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question 3 fill in the gaps in the following table, assuming each colum…
Filling the gaps (assuming neutral atoms, \( \text{Electrons} = \text{Protons} \), \( \text{Mass No} = \text{Protons} + \text{Neutrons} \)): - **Cd**: Electrons = 48 (matches Prot…
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3 lélectrolyse de leau consiste à en séparer les constituants, cest-à -…
- a) Représentation : Mêmes molécules H₂O, arrangement plus espacé que dans l'eau solide. - b) Représentation : Mêmes atomes d'or, arrangement modifié pour la forme du bijou. - c)…
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question 2 1 pts in a 2020 paper, arya udry et al. cautioned that altho…
A. proxies for
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a roller coaster car traveling uphill has an initial potential energy o…
A. There was 500 J of work done by friction as the car traveled up the hill.
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drag and drop the words or phrases to accurately complete the diagram. …
Left blank: thermal energy Right blank: thermal energy
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1 mark for review which of the following correctly indicates whether th…
C. It does not conduct electricity because its ions cannot move freely within the solid.
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10. model with math in a chemical compound, there are 3 parts zinc for …
The amount of zinc is 60 grams. The equation is \( \frac{3}{16} = \frac{z}{320} \) and its solution is \( z = 60 \).
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list as many differences between these three species as you can. check …
- Number of oxygen atoms differ. - The solubility in water differ. - \( \text{SO}_4^{2-} \) is ion, \( \text{SO}_2 \) and \( \text{SO}_3 \) represent molecular compounds.
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write the correct formula for each species: sulfur dioxide, sulfur trio…
- All contain 1 sulfur atom. - All contain sulfur and oxygen. - All contain nonmetals only.
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write the correct formula for each species: sulfur dioxide, sulfur trio…
$SO_2$, $SO_3$, $SO_4^{2-}$
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a compound contains only nitrogen and oxygen and has a formula mass of …
$\ce{N2O}$
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calculate the formula mass for hydrochloric acid. express your answer i…
\( 36.46 \)
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give the correct formula for hydrochloric acid. express your answer as …
$\ce{HCl}$
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give the correct formula for hydrochloric acid. express your answer as …
$\ce{HCl}$
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calculate the formula mass for copper(i) sulfate. express your answer i…
\(223.17\)
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part e give the correct formula for copper(i) sulfate. express your ans…
\( \text{Cu}_2\text{SO}_4 \)
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calculate the formula mass for dinitrogen trioxide. express your answer…
\( 76.02 \)
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give the correct formula for dinitrogen trioxide. express your answer a…
\( \text{N}_2\text{O}_3 \)
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calculate the formula mass for barium chloride. express your answer in …
208.23
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give the correct formula for barium chloride. express your answer as a …
\( \text{BaCl}_2 \)
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c₇h₁₆ express your answer in atomic mass units to two decimal places. f…
100.20
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fe(no₃)₃ express your answer in atomic mass units to two decimal places…
241.88
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c₆h₁₂o₆ express your answer in atomic mass units to two decimal places.…
180.16
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cs₂ express your answer in atomic mass units to two decimal places. for…
76.15
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what is the formula mass of a compound? it is the sum of the atomic mas…
A. It is the sum of the atomic mass of all elements in the chemical formula.
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eight dinitrogen monoxide molecules express your answer as an integer. …
24
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seven sulfur dioxide molecules express your answer as an integer. atoms
21
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eight dinitrogen monoxide molecules express your answer as an integer. …
24
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eight dinitrogen monoxide molecules express your answer as an integer. …
24
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the name trisodium phosphate is incorrect for the compound na₃po₄ becau…
B. you cannot use a prefix for the first element of an ionic compound.
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part a what is the correct name for the bro₄ ¹⁻ ion? ○ hypobromite ○ br…
C. perbromate
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part a what is the correct formula for potassium dichromate? kcr₂o₇ k₂c…
B. \(K_2\text{Cr}_2\text{O}_7\)
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for each solute, click the button under the better solvent. | solute | …
- For the first solute (benzene - like structure): \(CH_3(CH_2)_4CH_3\) is the better solvent. - For \(CaCl_2\): \(CH_3OH\) is the better solvent. - For \(NH_4Br\): \(CH_3CH_2OH\)…
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where do you need to orient your eye level to take an accurate reading …
Exactly parallel to the meniscus
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write the correct formula for each species: sulfur dioxide, sulfur trio…
$\ce{SO_4^{2-}}$ is ion, $\ce{SO_2}$ and $\ce{SO_3}$ represent molecular compounds, The solubility in water differ, Number of oxygen atoms differ. (Corresponding to the first, thi…
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write the correct formula for each species: sulfur dioxide, sulfur trio…
A. $\ce{SO_4^{2-}}$ is ion, $\ce{SO_2}$ and $\ce{SO_3}$ represent molecular compounds. C. The solubility in water differ. D. Number of oxygen atoms differ.
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list as many differences between these three species as you can. check …
- $\boldsymbol{\ce{SO_4^{2-}}}$ is ion, $\ce{SO_2}$ and $\ce{SO_3}$ represent molecular compounds. - The solubility in water differ. - Number of oxygen atoms differ.
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write the correct formula for each species: sulfur dioxide, sulfur trio…
- \( \ce{SO4^{2-}} \) is ion, \( \ce{SO2} \) and \( \ce{SO3} \) represent molecular compounds. - The solubility in water differ. - Number of oxygen atoms differ.
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part c list as many differences between these three species as you can.…
- $\ce{SO_4^{2-}}$ is ion, $\ce{SO_2}$ and $\ce{SO_3}$ represent molecular compounds - Number of oxygen atoms differ - The solubility in water differ
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write the correct formula for each species: sulfur dioxide, sulfur trio…
- All contain 1 sulfur atom. - All contain nonmetals only. - All contain sulfur and oxygen.