化学
化学反应、化学计量、分子结构与元素性质。
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randy was in an earthquake. afterwards she talked to her neighbors, who…
C. misinformation effect
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assuming 50% efficiency, 150 kcals of chemical energy would result in _…
B. 75 kcals
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types of atoms atomic number an element is the simplest form of matter …
Fluorine: Number of protons: 9 Number of electrons: 9 Iodine: Number of protons: 53 Number of electrons: 53
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a reaction where reactants are methane and elemental oxygen, and carbon…
B. combustion reaction
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large doses of vitamin c are supposed to cure the common cold. one comm…
7.7
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go online to explore and explain the makeup and properties of atoms and…
Most of an atom's mass is accounted for by protons and neutrons (in the nucleus). Most of an atom's volume is accounted for by the electron cloud (where electrons are found).
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question 4 10 pts if the following reaction is balanced correctly cucl₂…
C. 2
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amoeba sisters video recap: general lab safety. the illustrations below…
1. Wear proper lab clothing, gloves, goggles. 2. Keep walk - ways clear of bags. 3. Dispose of broken glass in proper container. 4. Do not take chemicals out of the lab. 5. Do not…
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final exam the palmer raids in the palmer raids, a. mitchell palmer and…
A. Federal Bureau of Investigation
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if the following reaction is balanced correctly cu + o₂ → cuo the coeff…
D. 2
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opción múltiple el combustible debe calentarse hasta su punto _________…
# Breve explicación: El combustible debe calentarse hasta su punto de inflamabilidad para iniciar la reacción química en cadena. # Respuesta: D. Punto de inflamabilidad
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el combustible debe calentarse hasta su punto ______________ para que c…
# Breve Explicación: El punto de inflamabilidad es la temperatura a la que un combustible puede encenderse y comenzar una reacción química en cadena. # Respuesta: Punto de inflama…
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how many neutrons are in a neutral aluminum atom? * *only type the numb…
14
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¿el fuego es un ______________? ○ deformación del espacio ○ proceso de …
Reacción química
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question 2 10 pts in the reaction 2 ba(no₃)₂(s)→δ 2 bao(s)+4 no₂(g)+o₂(…
B. reactant
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5. the mass spectrum represented to the right is most consistent with w…
B. Gd ### 6.
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match the following descriptions with its corresponding subatomic parti…
- Holds the nucleus together: Neutrons - Lives outside the nucleus: Electrons - Equals the atomic #: Protons - Determines the element: Protons - Responsible for reactions/bonding:…
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1. what ion will be formed by the phosphorus atom shown below when it h…
P3-
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part ii: multiple choice: merely circling the answers does not mean you…
1. B. $\frac{5.0\ g}{56.0\ g/mol}$ 2. A. The molar mass of $Cu$ 3. D. $N_2O_5$ 4. B. 91 amu
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a chemist puts 0.15 liters of liquid in each of 57 beakers. how much li…
$8.55$ liters
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what does the forward arrow in a chemical equation mean? (1 point) the …
The reaction yields something.
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what happens during rusting of an iron nail? (1 point) sulfur, iron, an…
Iron and oxygen combine to form iron oxide.
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chemical reactions quick check how do catalysts affect a chemical react…
lower activation energy
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question 8 (3 points) title: ch - 01 - 12 based on its formula, sugar c…
B. a compound
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question 1 10 pts which of the following is not a sign of a chemical re…
A liquid mixture turns into a solid after water evaporates from it.
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question 7 (3 points) title: ch - 01 - 03 brass is an alloy that resist…
C. homogeneous mixture
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chemistry (1 cr): section u60017tdfc > unit 1 elements and the periodic…
C. atoms
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question 5 (3 points) title: ch - 01 - 10 pencil \lead\ is actually mad…
B. an element
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question 3 0.5 pts the figure shows a liquid measurement using a 50 ml …
35.25 mL
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question 4 (3 points) title: ch - 01 - 04 strawberries contain vitamins…
A. Vitamins E, B, and C
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question 6 0.5 pts a student determines the mass of a sample of water b…
9.03g
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does this equation follow the law of conservation of mass? h₂so₄ + naoh…
No
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question 3 (3 points) title: ch - 01 - 08 which of the following contai…
C. compounds
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what is the mass for the miss formula below? (do not label the answer) …
55
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which of the following statements is always true for the law of conserv…
The mass is constant
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question 5 0.5 pts if a student determined that the volume of a sample …
0.96g/mL
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what is the total number of atoms on the reactant side of the chemical …
32
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how many protons does a neutral atom of aluminum have? *only type the n…
1. 13 2. Democritus
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what is a function of the integumentary system? (1 point) forms blood c…
forms blood clots
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question 2 (3 points) title: ch - 01 - 13 based on its formula, carbona…
C. mixture
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question 1 (3 points) title: ch - 01 - 09 which of the following contai…
B. elements
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question 23 of 25 which of the following would be a good situation in w…
C. When the $\Delta H_{reaction}$ is not known
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question 22 of 25 what information does gibbs free energy give about a …
B. It tells if the reaction will proceed spontaneously or not.
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question 21 of 25 what can be said about the reaction 2nh₃(g) → n₂(g) +…
D. The reaction is endothermic.
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question 20 of 25 what is the value for δg at 5000 k if δh = -220 kj/mo…
C. 30 kJ
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question 18 of 25 what best describes the enthalpy of formation of a su…
C. The energy change that happens when a substance forms from its elements
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fill in the grid for the element arsenic: *some may be used more than o…
| Property | Value | |--|--| | Atomic mass | 74.95 | | # of Protons | 33 | | # of Electrons | 33 | | # of Neutrons | 42 | | Atomic number | 33 |
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what is the thermal energy of a system? a. the average speed of molecul…
D. The total kinetic energy of the particles in a system
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question 15 of 25 how is entropy related to the spontaneity of a reacti…
B. $\Delta S > 0$ contributes to spontaneity.
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question 14 of 25 how does the entropy change in the reaction 2c3h6(g) …
C. The entropy increases.
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question 13 of 25 what does the δh of a reaction represent? a. it repre…
A. It represents the heat involved in a reaction.
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question 10 of 25 two kittens are sleeping in a sunny spot. they are re…
A. Radiation warming
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question 9 of 25 what would cause entropy to increase in a reaction? a.…
C. The products becoming more spread out
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question 7 of 25 what does it mean for heat to be transferred by convec…
C. Energy is transferred through moving currents of warmer air or liquid.
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question 6 of 25 how is stoichiometry used to calculate energy absorbed…
B. Grams liquid × mol/g × $\Delta H_{vap}$
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what is specific heat capacity? a. the energy required to completely me…
B. The energy needed to change the temperature of a substance
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question 3 of 25 what information does the potential energy diagram rev…
B. It shows whether the reaction is exothermic or endothermic.
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what can be said about a reaction with $delta h = - 890$ kj/mol and $de…
A. It is always spontaneous.
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what two subatomic particles make up an elements atomic mass? * atoms p…
B. Protons, D. Neutrons
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question 2 of 25 what can be said about a reaction with $delta h=-890$ …
There is no correct option among A, B, C, D. If we assume there is a small error in the calculation of the equilibrium temperature and consider the closest conceptually correct op…
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question 1 of 25 what volume of water can be boiled by 3.0 kj of energy…
D. 3.0 kJ×$\frac{1\ mol}{40.65\ kJ}$×18.02 g/mol×$\frac{1\ mL}{1\ g}$ = 1.3 mL
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people breathe in oxygen molecules from the air and exhale carbon dioxi…
B. An increase in entropy
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question 7 of 10 which of these statements is true of rocket flight but…
C. It has the ability to create lift in a vacuum.
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if an engineers greatest concern is easy maintenance of a rocket throug…
A. Solid chemical fuel
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question 1 of 10 which term below describes the study of how energy is …
D. Thermodynamics
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how can a reaction with a negative value of $delta g^{0}$ be described?…
A. As spontaneous
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question 26 of 27 the temperature of 500 ml of water is 16°c. what happ…
B. The temperature of the water increases because the average kinetic energy of the water molecules increases.
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you need to calculate the enthalpy change ($\\delta h^{\\circ}$) of the…
A. $\Delta H^0=\Delta H^0_1-\Delta H^0_2$
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question 24 of 27 for a phase change, $delta h^{0}=2 kj/mol$ and $delta…
B. $\Delta G=-6.5\ kJ$; spontaneous
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question 23 of 27 the enthalpy of a reaction is -394 kj/mol. how would …
A. Exothermic
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question 7 (10 points) choose an element and imagine that it has a care…
Iron can be thought of as a hard - working and strong element. It could have a "career" in construction, being used for building frameworks. It is busy due to its wide industrial …
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question 22 of 27 what are the signs of the enthalpy (δh) and entropy (…
A. -$\Delta H$, +$\Delta S$
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question 20 of 27 which is characteristic of an exothermic reaction? a.…
C. Material releases heat to its surroundings.
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question 6 (3 points) which element in group 6 is found in emeralds and…
B. Chromium (Cr)
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question 19 of 27 what must happen for water to boil at a given pressur…
A. The water must gain thermal energy from its surroundings.
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at 298 k, $delta h^{0}=46$ kj/mol and $delta s^{0}=0.097$ kj/(k·mol). w…
D. 17 kJ
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which alkaline earth metal produces the red color seen in fireworks? o …
D. Strontium (Sr)
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write a lewis structure for the formate ion (hco₂⁻). include all resona…
The bond order of the $C - O$ bonds in the formate ion ($HCO_2^-$) is 1.5. The resonance hybrid structure has a carbon atom double - bonded to one oxygen and single - bonded to th…
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question 16 of 27 the diagram below shows how the potential energy chan…
B. The reaction is exothermic because the energy of the $CO_2$ and $H_2O$ is less than the energy of the $C_3H_8$ and $O_2$.
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for a reaction, $delta h^0 = 206 kj/mol$ and $delta s^0 = 0.215 kj/(kcd…
B. At temperatures greater than 958 K
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question 4 (3 points) is arsenic (as) a metal, non - metal, or metalloi…
C. Metalloid
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question 13 of 27 at what temperatures is a reaction that has a positiv…
B. At all temperatures for exothermic reactions
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question 3 (3 points) what element from group 15 may have been used to …
C. Arsenic (As)
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question 12 of 27 what happens to water as it boils? a. the intermolecu…
C. The energy that is absorbed overcomes the intermolecular forces that hold the molecules together.
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how is hesss law used to calculate the enthalpy change of a reaction? a…
A. The enthalpy changes of each step of the reaction are added together.
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question 10 of 27 what is the change in enthalpy of the first reaction …
C. -112 kJ
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question 8 of 27 the reaction below shows how the potential energy chan…
C. The change in enthalpy is negative, and the reaction is exothermic.
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question / of 2/ what is the best definition of the enthalpy of formati…
C. The energy required for a molecule to form from its elements
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question 2 (3 points) find one element named after a planet. list its n…
Name: Uranium; Period: Seventh period
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question 6 of 7 for a reaction, δh = -286 kj. when is the reaction spon…
B. When $T\Delta S > 0$
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search the table use the periodic table to answer the following questio…
C. Tantalum (Ta)
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question 4 of 27 during a reaction, the enthalpy of formation of an int…
D. -572 kJ
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question 3 of 27 the thermochemical equation for the reaction in which …
B. It is endothermic.
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what volume of gold would be equal in mass to a piece of copper with a …
$63.1$
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heptane and water do not mix, and heptane has a lower density (0.684 g/…
$10.2$
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what is the correct formula for a compound containing strontium and pho…
C. $Sr_3P_2$
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what is the formula for a beryllium atom achieves noble gas configurati…
Be⁺²
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7 multiple choice 1 point which of the following is likely to form an i…
Potassium and Fluorine
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question 6 of 9 a fume hood is primarily used in a laboratory to: provi…
Minimize exposure to hazardous airborne substances.
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what do we call a positively charged ion proton anion positron cation
D. cation