Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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a 126 - gram sample of titanium metal is heated from 20.0°c to 45.4°c w…
A. \(0.525\ J/g\cdot^{\circ}C\)
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a 23.7 g piece of iron at 54.9°c is cooled and releases 338 j of heat. …
d \(23.2^{\circ}C\)
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what mass of ethanol will release 410.0 j of heat when it cools from 32…
A. 12.8 g
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the molar mass of copper is 63.546 g/mol. the specific heat of copper i…
A. 548 J
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how much energy is required to heat 0.24 kg lutetium from 296.2k to 373…
D. 2857 joules
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how much heat would need to be absorbed by 1.5 g of liquid water to rai…
A. \(191\space J\)
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roberto wants to measure the lengths of the sides of a metal cube. whic…
ruler, electronic balance, graduated cylinder, thermometer
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roberto wants to measure the lengths of the sides of a metal cube. whic…
electronic balance
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roberto wants to measure the lengths of the sides of a metal cube. whic…
graduated cylinder
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this excerpt describes the issues leading up to the great compromise. \…
1. equal 2. Great 3. two 4. population 5. equal
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consider this system at equilibrium. caco₃(s) ⇌ ca²⁺(aq) + co₃²⁻(aq) th…
\(Na_{2}CO_{3}\)
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sodium chloride is made up of clear, colorless crystals. a solution of …
It is made up of ions that are held together by ionic bonds.
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which compound contains both sigma and pi bonds? hccl₃ hbr h₂co h₂s
\(H_2CO\)
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directions: balance the following equations: 1. ___ nai + ___ f₂ → ___ …
1. \(2\ NaI+1\ F_2 ightarrow 2\ NaF + 1\ I_2\) 2. \(3\ Ca+1\ N_2 ightarrow 1\ Ca_3N_2\) 3. \(1\ Pb(ClO_2)_4+2\ ZnSO_4 ightarrow 1\ Pb(SO_4)_2+2\ Zn(ClO_2)_2\) 4. \(2\ LiOH ightarr…
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denise heats a beaker of dilute acid on a hot plate in a fume hood. wha…
goggles, a lab coat, heat - proof gloves, and close - toed shoes
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what is the best reason for a student to remove a dangling bracelet whe…
to minimize the chance the bracelet pulling over a test tube, causing a spill
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what information is given in the msds for acetic acid? the mass of acet…
the reactivity of acetic acid with various chemicals
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the msds for chloroform indicates that it is a clear liquid that has a …
He should locate the chloroform stored in a dark container in chemical storage and should take it to the fume hood to pour.
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the msds for benzene indicates that it is a clear liquid that has a sub…
Benzene must be kept away from flames.
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what information is given in the msds for acetic acid? the mass of acet…
the reactivity of acetic acid with various chemicals
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forrest spills some acid on the lab floor. he notifies his teacher and …
other students in the lab
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which compound contains both sigma and pi bonds? hccl₃ hbr h₂co h₂s
\(H_2CO\)
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what is a common use of bases? as a component of car batteries to reduc…
to reduce indigestion
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emily spills concentrated sodium hydroxide solution on her lab bench. w…
Notify her teacher.
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where in the laboratory is long, unrestrained hair most likely to be a …
near an open flame
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consider the chemical reaction in equilibrium. h₂ + i₂ + heat ⇌ 2hi wha…
The direction of the chemical equilibrium will shift to the right, favoring the forward reaction.
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consider the word equation. calcium hydroxide + hydrochloric acid → cal…
\(Ca(OH)_2(s)+2HCl(l)\to CaCl_2(aq)+2H_2O(l)\)
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the msds for chloroform indicates that it is a clear liquid that has a …
He should locate the chloroform stored in a dark container in chemical storage and should take it to the fume hood to pour.
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water is dissolved into n - butanol (a polar liquid). which is the seco…
n - Butanol molecules surround water molecules.
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ca(oh)₂ is added to a large beaker of water. how is the solution differ…
The solution turns phenolphthalein pink.
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the msds for benzene indicates that it is a clear liquid that has a sub…
Benzene must be kept away from flames.
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if you find a chemical in the lab and are unsure of its identity, what …
- the identification of the chemical - the chemical and physical properties of the substance - the first - aid measures to take if an accident occurs involving the chemical
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if you find a chemical in the lab and are unsure of its identity, what …
read the label on the container
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a single atom of an element has 21 neutrons, 20 electrons, and 20 proto…
Ca
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a scientist researching methods to convert used motor oil into gasoline…
breaking molecules into smaller chains
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ionization energy atomic radius reactivity the state or power of being …
- Ionization Energy: The minimum energy required to remove an electron from a neutral atom or molecule in its gaseous state. - Atomic Radius: The distance from the nucleus of an a…
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calcium fluoride (caf₂) has a solubility constant of 3.45×10⁻¹¹. what i…
\(2.05\times 10^{-4}M\)
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which best describes a compound such as magnesium oxide? a mixture of t…
a pure substance that is made up of different elements
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consider this system at equilibrium. caco₃(s) ⇌ ca²⁺(aq) + co₃²⁻(aq) th…
\(Na_{2}CO_{3}\)
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john is completing a lab in which he is using the corrosive base sodium…
- Tie hair back - Only burn the amount of chemicals as directed by the lab procedure
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john is completing a lab in which he is using the corrosive base sodium…
wear safety goggles, wear a lab coat, read any safety information, such as the SDS before he begins the experiment
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sodium chloride is made up of clear, colorless crystals. a solution of …
It is made up of ions that are held together by ionic bonds.
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what is the name of the ionic compound rbcl? chlorine rubidide rubidium…
rubidium chloride
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question 11 the total number of atoms indicated by the formula na2co3 is
A. 6
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according to the collision theory, which is required for a high number …
- molecular collisions with energy to overcome activation energy - molecular collisions that have very specific orientations
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which is the formula for diarsenic pentoxide? as₅o₂ ar₂o₅ as₂o₅ 2as5o
C. \(As_2O_5\)
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the chemical formula sf₆ indicates a six atoms of sulfur and one atom o…
D. one atom of sulfur and six atoms of fluorine
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how many of the following statements regarding daltons atomic theory is…
C. 2 (Statements I and III are still believed to be true)
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which of the following did dalton discuss in his atomic theory? a. isot…
F. Dalton's theory did not discuss any of these topics.
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you are writing a safety contract for your class. list 10 things you wo…
If it is a general classroom safety contract: 1. Follow all teacher instructions promptly. 2. Keep hands, feet and object to oneself. 3. Use classroom equipment as directed. 4. Re…
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which of the these shows a bronsted-lowry acid reacting? nh₃ + h⁺ → nh₄…
\(HCl + H_{2}O ightarrow H_{3}O^{+}+Cl^{-}\)
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which best describes the function of a centrifuge? to separate the diss…
to separate the undissolved particles of a mixture into layers
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given is a list of chemical reactions. 1. burning octane fuel 2. formin…
1, 3, 2, 4
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which statement best describes a pair of elements that will form an ion…
Ca and Br: Calcium easily loses electrons, and bromine gains them.
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which of the following did dalton discuss in his atomic theory? a isoto…
C. 2
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question 7 the law of constant composition applies to a heterogeneous m…
C. compounds
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in an experiment, a student wants to increase the rate of a reaction th…
Decrease the volume to increase pressure and to increase concentration.
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what is the element ar classified as in the periodic table? a noble gas…
a noble gas
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ethylene, a gas found in nature, is commonly used to ripen bananas and …
La tercera estructura (con la doble unión \( C = C \) y dos átomos de \( H \) unidos a cada \( C \)) es la etileno.
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an element has five valence electrons available for bonding. this eleme…
phosphorus
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consider the unbalanced equation for the oxidation of aluminum. _al + _…
# Explanation: ## Step1: Balance el oxígeno En el lado[SSE Completed, Client Connection Error][SSE Completed, Client Connection Error][LLM SSE On Failure]
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four substances are tested for different properties. the results of the…
# Explicaciones breves: Los alcanos son hidrocarburos no reactivos (debido a enlaces C - C y C - H fuertes y no polares), combustibles (contienen carbono y hidrógeno, que se combi…
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what is the electron configuration of the sodium atom after it loses an…
A. \(1s^{2}2s^{2}2p^{6}\)
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which is not true of the sc³⁺ ion? a) it was formed by the loss of 4s a…
A. It was formed by the loss of 4s and 3d electrons.
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two students are given two different size blocks of the same substance …
C. boiling point because it is an intensive property
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which statement explains how the bands in the crystal of a metal are li…
They both allow electrons to move from lower energy levels to higher energy levels.
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why is the calcium ion (ca²⁺) more stable than the calcium atom (ca)? a…
A. The noble gas configuration is more stable.
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solid strontium chromate, srcro4, dissolves into its respective ions at…
\(3.6\times 10^{-5}\) (la tercera opción)
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a beam of light passes though a liquid in a test tube without scatterin…
solution
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which is true of transition metals when moving from left to right on th…
Atomic radii decrease slightly and then start to increase.
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a teacher wants to perform a classroom demonstration that illustrates b…
burning a candle
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date: name(s): 5. for the reaction below, initially 3.5 mol of nh, are …
a. \(0.16\ mol/(L\cdot min)\) b. \(0.24\ mol/(L\cdot min)\) c. \(0.20\ mol/(L\cdot min)\)
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which statement best describes what makes a base weak? a base is weak w…
A. A base is weak when it forms few ions in water.
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16. which is generally true of metals? a. they are poor conductors of h…
16. B. They are good conductors of heat 17. C. metals 18. A. The particles will sit on the bottom without dissolving. 19. D. It will increase the solubility of a solid and decreas…
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which element would most likely have chemical properties similar to tha…
Br
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what is the chemical formula for iron (ii) hydroxide? fe(oh)₂ fe₂oh feo…
\(Fe(OH)_2\)
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11. which of the following has a covalent bond? a. nabr b. n₂o c. also₄…
B. \(N_2O\) # 12.
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which is a feature of a single replacement reaction? substance g reacts…
Substance \( G \) reacts with compound \( XY \) to form \( GY \) and \( X \).
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which statement is true about crystal lattice energy? it is the energy …
It is a measure of the strength of the bonds between ions.
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which element is likely to have a high thermal conductivity? antimony s…
sodium
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8. when mercury oxide is heated, it forms mercury and oxygen. hgo→hg + …
21
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condensation reaction is a chemical reaction in which ________ molecule…
A. two
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how does the strength of intramolecular bonds within a water molecule c…
C. The intramolecular bonds within a water molecule are stronger than the intermolecular bonds between water molecules.
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the reaction of a lewis acid with a lewis base would most likely be acc…
covalent bonds
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why does ice float on liquid water? a liquid water is less dense than i…
C. Water expands when it freezes.
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an experimental procedure requires 10 ml of acid to be dissolved into a…
the concentration of acid in the solution has been increased
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what gives water most of its unique properties? a the oxygen in its mol…
C. hydrogen bonding between water molecules
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in which orbitals would the valence electrons for carbon (c) be placed?…
s orbital and p orbitals
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when a drawing of a circle made in the center of a piece of paper with …
chromatography
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8. when mercury oxide is heated, it forms mercury and oxygen. hgo→hg + …
21 ### Question 9
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the table gives the numbers of protons, electrons, and neutrons in four…
3
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consider the hydrocarbon. what is the name of this hydrocarbon? 1 - but…
1-pentyne
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what are hydrogen bonds? a weak bonds between the hydrogen atoms of wat…
C. Weak bonds between the oxygen atom of one water molecule and a hydrogen atom of another.
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the diagram shows that the periodic table is divided into different blo…
p block.
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in a water molecule, how do the electrical charges compare between oxyg…
C. The oxygen atom is slightly negative in charge, while the hydrogen atoms are slightly positive in charge.
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semester a assuming the compound is dissolved in water, what is the for…
$H_3PO_3$
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the periodic table shows the electronegativity values of some elements.…
barium
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the image shows what happens when an antacid tablet is placed in water.…
rapid chemical reaction where gas is released.
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question 4 of 5 vaping can cause chemical burns in your lungs. false, n…
C. True, vaping injury like chemical burns have been reported by doctors.
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complete the text with the correct pair of words. could you ____ these …
take...a part