Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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draw the lewis structure of n₂. click to draw a new structu
``` :N≡N: ```
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a lewis structure with placeholder elements is shown. if the formal cha…
B. \( Cl, Br, \text{or }I \)
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what is the ratio amount (mol) f atoms ? amount (mol) c atoms enter you…
\(1\)
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is this a thesis statement? rosalind franklin should have won the 1962 …
Yes
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mass: 3.00 g molar mass percent compositions h₂o 18.015 11.18 h 88.81 o…
4
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chemistry students are learning about lewis structures. their instructo…
II
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add commas, semicolons, or colons if needed. otherwise, submit the text…
Unfortunately, most people are unaware of the contributions of female scientists such as Ida Noddack, a German chemist, Cecilia Payne - Gaposchkin, an American astronomer, and Mur…
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which of the lewis structures in the image is correct?
A. \(Br - \begin{array}{c} \ddot{S}\\ | \\ Br \end{array}-Br\)
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add commas, semicolons, or colons if needed. otherwise, submit the text…
Unfortunately, most people are unaware of the contributions of female scientists such as Ida Noddack, a German chemist, Cecilia Payne - Gaposchkin, an American astronomer, and Mur…
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elements, compounds, and mixtures classify each of the pictures below b…
1. \(B\) 2. \(C\) 3. \(E\) 4. \(E\) 5. \(A\) 6. \(B\) 7. \(A\)
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what element is isoelectronic with co^{+6}? answer by inputting the sym…
\(Sc\), \(21\)
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question 11 0.75 pts what is the complete electronic configuration for …
1s22s22p63s23p64s23d104p64d2
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the aluminum is allowed to react with the sulfuric reaction until it st…
- Partial pressure of hydrogen gas: \(722.8\) torr - Moles of hydrogen gas: \(0.0255\) mol - Mass of aluminum reacted: \(0.459\) g
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question 7 a mixture of three noble gases (he, ne and ar) is confined t…
- Total pressure: \(7.54\space atm\) - Mole fraction of Ne: \(0.156\) - Mass of Ar: \(25.9\space g\)
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a molecular - level representation of a mixture of two gases (a and b) …
Mole fraction of gas A: \(0.615\) Mole fraction of gas B: \(0.385\) Partial pressure of gas A: \(89.2\ kPa\) Partial pressure of gas B: \(55.8\ kPa\)
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question 1 metal carbonates react with acid to produce a salt, water an…
\(11.84\) ### Question 2 #### Part 1
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sigfigcalc3. an empty beaker weighs 12.408g. after some solid is added …
B. \(0.300\ \text{g}\)
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read the sentence. 1 alejandros guidance counselor is helping him plan …
sentence 3
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read the paragraph. 1 ji - yoo is brainstorming topics for a term paper…
sentences 3 and 6
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you are conducting a flame test with three unknown substances. the flam…
Red flame - likely calcium (\(Ca^{2 + }\)), blue flame - likely copper (\(Cu^{2+}\)), yellow flame - likely sodium (\(Na^{+}\))
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what is an atom? one of the states of matter a type of energy the tinie…
The tiniest building blocks that all matter is made of.
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which of these is true about atoms? scientists have never observed an a…
Atoms are too small to see with our eyes.
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read the paragraph. 1 alejandros guidance counselor is helping him plan…
sentence 4
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read the paragraph. 1 alejandros guidance counselor is helping him plan…
sentence 3
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write the balanced net ionic equation for the reaction when hi and sr(o…
\(H^{+}(aq)+OH^{-}(aq)\to H_2O(l)\)
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3 multiple answer 3 points which of the following statements about meta…
- Metals can be drawn into wires. - Metals in solid form have specific crystal structures. - Metals can be hammered into different shapes.
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2 fill in the blank 2 points fill in the blanks to complete the sentenc…
electrons
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a group of high school chemistry students is practicing how to write mo…
- Correct Formula: $\ce{N2O}$, $\ce{SO2}$, $\ce{CCl4}$ - Incorrect Formula: $\ce{CaCl4}$, $\ce{S2O2}$, $\ce{NO2}$
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acidity changes after dry ice is added what happens to the acidity of s…
The pH of solution A decreases, and the pH of solution B decreases.
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the decomposition of organic matter in the presence of oxygen choose an…
aerobic decomposition
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9. you just determined that the isotope rubidium - 85 is most abundant …
\(_{37}^{85}\text{Rb}\)
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8. the atomic mass of rubidium is 85.47 amu. predict which isotope of r…
rubidium - 85
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true or false 1 point the name of the formula pbcl4 is lead tetrachlori…
True
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3. add a neutron to the nitrogen - 14 nucleus. observe how the mass num…
protons, neutrons
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which of the following statements are supported by the data? select all…
The correct statements are: - The compound with the highest melting point is made up of ions held together by ionic bonds. - It takes more energy to overcome the attractive forces…
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3. click the plus sign next to \symbol\ and \abundance in nature\ to op…
A. \(7\) B. \(7\) C. \(7\)
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which of the following statements are true once the sodium chloride bon…
- The resulting sodium cation has a stable octet in its valence shell. - The resulting chlorine anion has a stable octet in its valence shell. - The electrostatic attraction betwe…
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select the correct answer. which is the best definition of a dietary su…
a pill, liquid or powder that is not a food item and contain some nutrients
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3. viscosity is property of matter. viscosity describes a fluids resist…
Viscosity is a physical property.
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a group of high school chemistry students is practicing how to write mo…
carbon tetrachloride: \( CCl_4 \) sulfur dioxide: \( SO_2 \) dinitrogen monoxide: \( N_2O \)
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two elements, x and y, have electronegativities of 3.0 and 0.9 respecti…
An ionic bond will form because the electronegativity difference is large, causing one atom to transfer electrons to the other.
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question 5 (1 point) what is a hydrate? salt that is thermally decompos…
an ionic compound containing water molecules that are bound weakly to the metal
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question 3 (1 point) how many moles of water, h₂o, are present in 75.0 …
4.17 moles
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69. a gas mixture contains 1.25 g n₂ and 0.85 g o₂ in a 1.55 l containe…
- Mole fraction of \(N_2\): \(x_{N_2}\approx0.626\), mole fraction of \(O_2\): \(x_{O_2}\approx0.374\) - Partial pressure of \(N_2\): \(P_{N_2}\approx0.682\space atm\), partial pr…
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consider the thermal decomposition reaction for magnesium sulfate monoh…
1. \(MgSO_{4}\) 2. the lowest whole - number ratio of different atoms in a compound
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exemptions of products from whmis some products are already covered by …
Warning labels should have been placed on the drums to indicate the chemical's highly flammable nature. Also, the worker should have been educated on safe handling procedures, inc…
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67. a 1.20 g sample of dry ice is added to a 755 ml flask containing ni…
\(1389\space Torr\)
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1) __ h_{3}po_{4}+__ koh ightarrow __ k_{3}po_{4}+__ h_{2}o 2) __ k+__ …
1. \(1\) \(3\) \(1\) \(3\) 2. \(6\) \(1\) \(3\) \(2B\) 3. \(1\) \(1\) \(1\) \(1\) 4. \(10\) \(2\) \(6\) \(1\)
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which is a complete sentence? two hydrogen atoms and one oxygen atom co…
The first sentence "Two hydrogen atoms and one oxygen atom compose each molecule of water." is a complete sentence.
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which best explains why blood is considered to be a suspension? it has …
It contains particles that can settle out.
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what are homogeneous mixtures of metals commonly called? alloys colloid…
A. alloys
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mixture a was made by mixing different components together, but it appe…
solution
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the water in a 150 - ml flask is poured into a beaker that contains 600…
ethyl alcohol because it has a much larger volume than water
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five milliliters (ml) of alcohol is poured into a beaker that contains …
C. alcohol and salt
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a nonaqueous solution has a solvent that is not water. which is an exam…
steel
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which is a characteristic of a solution? its particles scatter light. i…
"its particles are evenly distributed"
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which refers to a mixture that contains more than one phase in which th…
heterogeneous
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which substance is an example of a colloid? milk sugar and water tomato…
milk
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in which situation can a mixture always be called a solution? when ther…
when the mixture is homogeneous
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which method would increase the solubility of a gas? increasing the pre…
A. increasing the pressure
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a student was comparing the solubility of equal amounts of table salt a…
1
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which factor increases the rate of dissolution in an unsaturated soluti…
# Explicación breve: - La velocidad de disolución se ve afectada por varios factores. - Cuando se aumenta la temperatura, las partículas del solvente y el soluto tienen más energí…
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solutions and solubility a chemist dissolved crystals of an unknown sub…
its solubility
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which refers to the amount of a solute that will dissolve in a given vo…
solubility
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solute crystals are added to a solution until they begin to sink to the…
unsaturated
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a 1 - l soda bottle contains dissolved carbon dioxide gas. which bottle…
a bottle that is sealed
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which is the second step in the dissolving process? the solute is mixed…
The solvent molecules surround the solute particles.
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which is true about dissolving a polar substance in water? the solvent …
The solute particles are carried into the solution.
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1 multiple choice 2 points how does food waste contribute to economic s…
1. It leads to more efficient resource use and cost reduction 2. Decomposing organic material into nutrient - rich soil 3. They minimize harm to the planet
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2. circuits are drawn using various symbols that represent electrical c…
Resistor: 9, Battery: 12, Motor: 13, Switch: 10, Relay: 8, Junction Block: 15, Circuit Breaker: 11, Fuse: 4, Transistor: 6, Diode: 3, Ground: 5, Capacitor: 2, Connector: 14, Lamp:…
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circuits are drawn using various symbols that represent electrical comp…
- Resistor: 9 - Switch: 10 - Circuit Breaker: 11 - Diode: 3 - Connector: 14 - Battery: 12 - Relay: 8 - Fuse: 4 - Ground: 5 - Lamp: 1 - Motor: 13 - Junction Block: 15 - Transistor:…
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15. a gas expands in volume from 26.7 ml to 89.3 ml at constant tempera…
D. -9.5 J
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14. what is the change in internal energy, \\( \\delta u \\), for a sys…
C. -198 J
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rates of reaction and equilibrium consider the reaction below. $h_{2}(g…
\(4.9\times 10^{-1}\)
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solid barium sulfate dissolves into its respective ions at 25^{circ}c. …
\(3.10\times10^{-6}\)
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in the hypothetical reaction below, substance a is consumed at a rate o…
\(2.0\space mol/L\cdot s\) (la tercera opción)
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12. a sample of oxygen gas was found to effuse at a rate equal to three…
A. \( 288\ g/mol \)
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which is true about reaction rates? high reaction rates occur only in s…
Reaction rates are not related to spontaneity.
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consider this chemical reaction of bromothym blue indicator. it appears…
The solution will remain yellow.
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according to le chateliers principle, a change in pressure affects the …
Some of the reactants or the products are in the gaseous phase.
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11. arrange the following gases in order of increasing average molecula…
A. \(CO_2 < O_2<N_2 < He\)
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which statement is usually true about the relationship between activati…
High activation energy barriers result in low rates.
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a gas that has a volume of 28 liters, a temperature of 318 k, and an un…
\(2.57\)
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10. calculate the root - mean - square speed of the molecules in a samp…
B. \(515\text{ m/s}\)
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to dissolve in water, zinc (zn) should form a compound with carbonate (…
chloride (\(Cl^-\))
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which sulfate is soluble? barium sulfate mercury(i) sulfate gold(ii) su…
# Explicación breve: La ley general de solubilidad de sulfatos establece que los sulfatos de calcio (\(CaSO_4\)) son ligeramente solubles en agua. Los sulfatos de bario (\(BaSO_4\…
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which compound is soluble in water? iron(iii) hydroxide copper(ii) sulf…
nickel(II) chloride
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which ionic compound is water soluble? nh₄no₃ srso₄ cus znf
$NH_{4}NO_{3}$
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consider the reaction ( x longleftrightarrow y + 2z ). if the molar sol…
8.
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diatomic elements when writing an equation, it is important to remember…
1. \(2Li(s)+2H_{2}O(l) ightarrow H_{2}(g)+2LiOH(aq)\) 2. \(2Na(s)+Cl_{2}(g) ightarrow 2NaCl(aq)\) 3. \(2CaCO_{3}(s) ightarrow 2CO_{2}(g)+O_{2}(g)+2Ca(s)\) 4. \(FeSO_{4}(s)+BaCl_{2…
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answer in 1 - 2 sentences each. 1. what happens to the motion of partic…
1. Particles gain energy and motion increases. 2. Warm moist air cools on cold glass, water vapor condenses. 3. Sweat evaporation absorbs body heat. 4. Dry ice sublimating. 5. Mel…
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iron(ll) carbonate (feco₃) has a solubility product constant of 3.13 × …
\(5.59\times 10^{-6}\text{ M}\)
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how many iron atoms are contained in 354 g of iron? 2.62 × 1025 fe atom…
3.82×10²⁴ Fe atoms
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given that the ( k_{sp} ) of ( alpo_{4} ) is ( 9.84\times10^{-21} ) at …
$9.92\times 10^{-11}\text{ M}$
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question 24 (10 points) how many moles of fructose are in a sample cont…
\(2.37\text{ mol}\)
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3 numeric 1 point an unknown gas has a volume of 17 l, a temperature of…
$136$
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9. given the equation: 2 c₂h₆(g) + 7 o₂(g) → 4 co₂(g) + 6 h₂o(g) determ…
E. \(358\ L\) (the small difference in the final digit is due to rounding differences in the intermediate steps)
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question 23 (10 points) what mass (in g) does 3.99 moles of kr have? 14…
334 g
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26 physical science 1 bility equilibrium which compound is water solubl…
$\text{KCl}$
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if i have 2.9 l of gas at a pressure of 5 atm and a temperature of 323 …
160