Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
-
calculating solubility & concentration practice: the solubility of suga…
1. $0.3\ kg$ of salt is needed. 2. The concentration of the glucose solution is $0.2\ g/mL$. 3. $1000\ g$ of sugar is needed to make a saturated solution in $500\ mL$ at $20^{\cir…
-
practice: percent yield show all work for each problem below. the quest…
88.14%
-
match each term with the correct answer choice. then write the number o…
1. B. A solid substance formed from a liquid solution 2. G. Mixing two clear liquids and the solution turns pink 3. F. A change that results in the formation of new chemical subst…
-
gold - au 2. give one property of gold. 3. what particle determines how…
2. Malleability 3. Valence electrons 6. Good electrical conductivity 7. Bronze 8. In a regular, repeating pattern (metallic - crystal lattice) 9. Bronze has better sound - produci…
-
18. compare the properties of each of the following: | |sodium (na)|chl…
| | Sodium (Na) | Chlorine (Cl) | Sodium Chloride (NaCl) | |--|--|--|--| | State of Matter | Solid | Gas | Solid | | Reactive or Stable | Reactive | Reactive | Stable | | Practica…
-
12. what is the number of protons called? 13. what is a family of eleme…
12. Atomic number 13. A vertical column in the periodic table with elements having similar chemical properties 14. Because they are chemically inert under normal conditions 15. ta…
-
why would the methylene blue put in the water eventually move everywher…
Because the concentration of methylene blue was highest where the drops went into the water and will spread to areas of lower concentration.
-
20. although amino acids have “acid” in their name, some are acidic in …
The acidity or basicity of amino - acids in water is determined by the functional groups in their side - chains. Acidic amino - acids have extra carboxyl groups in side - chains, …
-
part 3: practice questions 1. what is the difference between an atom an…
An atom is the basic unit of an element, while a molecule is made up of two or more atoms chemically bonded.
-
match the question with the appropriate response. what subatomic partic…
- What subatomic particle number never changes?: 6. Protons - Some of the atoms in the table above different numbers of neutrons but the same number of protons. What are such atom…
-
19. a. label at least two covalent bonds in the diagram above. b. label…
a. Covalent bonds: The bond between carbon and nitrogen (C - N) and the bond between carbon and oxygen (C = O) are covalent bonds. b. Hydrogen bond: The dotted line between the hy…
-
using the letters a - d, list the order of the illustrations from when …
5. Without seeing the specific details of the illustrations clearly, a general order could be that the larger - sized initial pieces (C if it has larger structures) enter first, t…
-
convert the fischer projection formula into a representation that uses …
The carbon atom is in the center. The $-CH_3$ and $-CH_2 - CH_3$ groups are drawn as solid wedges coming out of the plane of the paper, and the $-H$ and $-NH_2$ groups are drawn a…
-
question 2 (2 points) on a scrap sheet of paper, draw the bohr model fo…
Blank 1: 2 Blank 2: 8 Blank 3: 8 Blank 4: 2 Blank 5: 2
-
you are going to adjust the volume of the container by clicking on the …
1. Reducir la velocidad de las moléculas de gas. 2. Las colisiones de las moléculas de gas con las paredes del contenedor. 3. Si es más pequeño, la presión aumenta; si es más gran…
-
question 1 (2 points) which part of the atom is organized into energy l…
A. electron cloud
-
name date physical science atomic models protons, electrons, and neutro…
Sketch atoms as described above with correct number of protons, neutrons in the nucleus and electrons in electron - shells for each atom (N - 14, O - 16, Cl - 35, Ca - 40, Mg - 24…
-
molecule assigned axe geometry polarity pn₂⁻ ax₂e v - shaped 120° polar…
For $PN_2^{-}$: Lewis structure: P is the central atom with double - bonds to two N atoms and a lone pair on P. For $ClO_3^{-}$: Lewis structure: Cl is the central atom single - b…
-
atoms, elements, and compounds madelyn roque 2. the smallest particle o…
C. Atom
-
atoms, elements, and compounds madelyn roque multiple - choice question…
pure, made of only one atom
-
question 1. a student is using a procedure to separate a mixture in the…
Part A. Distillation Part B. Differences in boiling points Part C. Separates a mixture into its individual components by vaporizing and condensing the more volatile components.
-
citing textual evidence in literature: tutorial how does the narrator f…
Mark details such as "The familiar sense of peace settles over me, of being here, alive and safe" to indicate the narrator's feelings.
-
consider combustion of natural gas (methane) in oxygen to from water an…
33.7
-
consider the combustion of propane with oxygen: 2 c₃h₈ + 7 o₂ --> 6 co₂…
A. oxygen
-
a \generic\ reactoin has the balanced equation: 3a + 4b --> c + 5d. if …
0.42
-
balance the equation: h₂so₄ + naoh --> na₂so₄ + h₂o. what is the coeffi…
1. C. 2 2. C. 3
-
5) microbes that munch oil topic: science/environment approx. lexile: ~…
C. Microbes can aid oil - spill cleanup when used carefully.
-
sch4c: chemistry, grade 12, college preparation unit 1: matter and qual…
| Substance | Element | Compound | Mechanical mixture | Solution | | ---- | ---- | ---- | ---- | ---- | | Oxygen | √ | | | | | Food colouring in water | | | | √ | | Salt | | √ | |…
-
3. how can non - metal elements achieve a stable electron - shell struc…
Non - metal elements can achieve a stable electron - shell structure like noble gases by gaining electrons to form anions, sharing electrons through covalent bonds, or accepting a…
-
1. metals lose electrons to form positive ions. the charge on the group…
1. Helium has 2 electrons in its outermost shell. Other noble gas elements have 8 electrons in their outermost shell. The difference is due to helium having only one electron shel…
-
learning check 1. a) what does the subscript in a chemical formula indi…
1. a) The number of atoms of the element it follows. b) There is 1 atom of that element. 2. 1 nitrogen atom; 3 hydrogen atoms. 3. $CH_4$ 4. $N_2O_4$
-
mary engle pennington, a chemist who helped advance home refrigeration,…
D. prominent
-
a student wants to create a liquid volcano. the student observes bubble…
The candy tablets being added to the drink.
-
which of these elements is found in both carbohydrates and water? carbo…
Oxygen
-
what is the basic unit of matter? atom molecule gas compound
A. atom
-
learning check 1. draw a simple outline of the periodic table. use shad…
A simple outline of the periodic table with appropriate shading for metals and non - metals as described above. ### 2.
-
how is matter conserved? no. of molecules change before and after react…
No. of Atoms remain same before and after the reaction
-
8. what is the calculated average atomic mass for the mystery element g…
24.31
-
3. kyle is doing a chemistry experiment and has 30 ml of a 25% solution…
25 ml
-
7. using the average atomic mass found on the periodic table, determine…
Krypton - 83 Sodium - 23 Aluminum - 27
-
3. kyle is doing a chemistry experiment and has 30 ml of a 25% solution…
25
-
which statement best describes the relationship between activation ener…
Reducing the activation energy can increase the rate of a reaction.
-
a scientist is conducting an investigation that involves water, silver,…
They are each made of matter. Some are compounds and some are elements. They all contain atoms.
-
in what form is carbon found in the atmosphere? co₂ c₆h₁₂o₆ h₂o atp
A. $CO_2$
-
a dietician asks a patient about the food that the patient eats and mak…
The patient should increase the amount of lean meats (proteins) and decrease the amount of oils in his or her diet.
-
which will increase the rate of a chemical reaction? 1. adding a cataly…
A. adding a catalyst
-
a scientist is examining the role of an element found in fats and carbo…
He is studying oxygen, which can also be found in proteins.
-
what can you conclude from the graph? the reaction that causes a firewo…
The reaction that causes a firework to explode requires less energy to start, and occurs more rapidly than the reaction that causes a candle to burn.
-
which statements about drugs and drug abuse do you think are myths? che…
If it's a prescription, it must be safe. You can't get addicted to something your doctor prescribes. "Natural" and "Organic" drugs are safer than synthetic ones. The era of heavy …
-
according to the video, what qualities do chemists need? check all that…
curiosity, ability to focus on details, painstaking follow - through
-
according to the video, what are some products invented directly by che…
drugs, fibers, paints, cosmetics, electronic components
-
according to the video, what are some fields the work of chemists affec…
energy development, medicine, food processing
-
4. complete the electron dot structures below to show how beryllium flu…
Draw 2 dots around Be for reactant Be, 7 dots around each F for reactant Fs. For the product, no dots around $Be^{2+}$, 8 dots around each $F^-$ to represent full - octet of fluor…
-
section 3: bonding in metals 1. how is the electrical conductivity of a…
1. The electrical conductivity of a metal is explained by metallic bonds because the delocalized electrons in metallic bonds can move freely under an electric field, facilitating …
-
4. complete the electron dot structures below to show how beryllium flu…
a. When dissolved in water, ionic compounds can conduct electricity. d. Ionic compounds are electrically neutral.
-
read the following information from a material safety data sheet (msds)…
Remove the shirt, and rinse the skin with water.
-
4. complete the electron - dot structures below to show how beryllium f…
5. solid 6. false 7. a. True, d. True
-
a scientist is working with methane (ch₄) and butane (c₄h₁₀). which sta…
They are matter made of the same two elements, but each contain different numbers of atoms.
-
which component is affected when a catalyst is added to a chemical reac…
the activation energy
-
how does a catalyst influence a chemical reaction? it speeds up or slow…
It decreases the amount of energy necessary for the reaction to proceed.
-
which reaction is exothermic? a reaction that absorbs energy from the e…
a reaction that releases energy into the environment
-
2) dry ice is solid carbon dioxide (co₂). normally, what phase is carbo…
2) Gas 3) Porque la presión atmosférica ambiente es demasiado baja para que el dióxido de carbono permanezca en estado sólido, lo que provoca la sublimación.
-
ionic and metallic bonding section 1: ions 1. for each element below, s…
1. - For Ba: - (i) 2 valence electrons - (ii) Electron - dot structure: Ba with 2 dots around it - (iii) $Ba^{2 + }$ - For I: - (i) 7 valence electrons - (ii) Electron - dot struc…
-
which is the best definition of activation energy? the energy required …
the energy required to form or break the bonds of reactant molecules
-
according to the video, what are some products mechanical engineers des…
engines robots kitchen appliances power tools
-
6. give the name and symbol of the ion formed when a. a chlorine atom g…
a. Chloride ion, $Cl^-$ b. Potassium ion, $K^+$ c. Barium ion, $Ba^{2+}$ d. Oxide ion, $O^{2-}$
-
which statement correctly describes a chemical reaction? reactants come…
C. Bonds between atoms break and reform.
-
3. in an ionic compound, the charges of the ____________ and __________…
cations; anions; neutral
-
a substance that influences the reaction but does not participate in th…
A. catalyst
-
what must happen before a chemical reaction can begin? the activation e…
The activation energy must be reached.
-
a researcher is designing a laboratory experiment to determine whether …
First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X…
-
4. pots and pans for cooking are often made of copper, aluminum, and ir…
4. Metallic bonding has delocalized electrons that enable efficient heat - conduction, making the metals suitable for cooking. 5. The sea of delocalized electrons in metallic bond…
-
if the activation energy required for a chemical reaction were reduced,…
The rate would increase.
-
3. name three properties of metals that can be explained by metallic bo…
1. Electrical conductivity: Delocalized electrons can carry an electric current. 2. Malleability: Layers of metal ions can slide over each other due to the electron - sea holding …
-
which statement best describes the amount of catalyst that remains at t…
The amount of catalyst is the same at the end as at the beginning of the reaction.
-
c11 writing and balancing word equations: with the following chemical r…
1. Balanced Chemical Equation: $2Na(s)+Cl_2(g) ightarrow2NaCl(s)$, Type of Reaction: Combination 2. Balanced Chemical Equation: $2Al_2O_3(s) ightarrow4Al(s) + 3O_2(g)$, Type of Re…
-
section 3: bonding in metals 1. how is the electrical conductivity of a…
1. In metallic bonding, delocalized electrons can move freely under a potential difference, enabling electrical conductivity. 2. Metallic bonds are the electrostatic attractions b…
-
which reason best explains why carbon is able to form macromolecules? c…
Carbon can bond with many elements.
-
9) at 30 degrees celsius and 90 atmospheres, what phase is bromine? 10)…
9) Líquido 10) Sólido
-
which statement best illustrates why carbon is so important to life on …
Carbon - based macromolecules are found in living things.
-
6) this is a phase diagram for bromine (br₂). label the areas on the di…
# Explicación: ## Paso 1: Comprender la diagramática de fases En una diagramática de fases, la región por debajo de la curva de fusión es sólida, la región entre la curva de fusió…
-
which substance is a compound? water gold oxygen hydrogen
water
-
5) add the phase changes from the word bank to the diagram. word bank: …
# Explicación: ## Paso 1: Identificar la transición de fase La transición de un sólido a un líquido se llama fusión. En el caso del hielo seco (dióxido de carbono sólido), cuando …
-
electronic cigarettes (also called electronic nicotine delivery systems…
Neither e - cigarettes nor traditional cigarettes should be used during pregnancy.
-
what element is considered the most versatile element in living organis…
carbon, because it can bond with many elements to form complex molecules
-
name: aystar c date: period: classwork - states of matter diagram part …
# Explicación paso a paso: ## Paso 1: Respuesta a la pregunta 2 Normalmente, el dióxido de carbono en la Tierra está en fase gaseosa. Esto se debe a que las condiciones normales d…
-
5) a flask that weighs 345.8 g is filled with 225 ml of carbon tetrachl…
### 5) # Explicación: ## Paso 1: Encontrar la masa del carbon tetrachloruro Restamos la masa del frasco de la masa total del frasco y el carbon tetrachloruro. $m = 703.55\ g - 345…
-
which statement correctly describes glucose (c₆h₁₂o₆)? it is made of ma…
It is a compound made of twenty - four total atoms.
-
before using any chemical in the lab, why should one first read the mat…
The MSDS provides information on safe handling of the chemical.
-
students are each given a 20 - gram sample of an unknown solid compound…
Each piece contains the same proportion of different elements.
-
if you were to put a sugar cube in water, it would dissolve. this tells…
Polar
-
density practice problem worksheet 1) a block of aluminum occupies a vo…
2.7 g/mL 2.
-
the diagram below shows the hydrogen bonds between water molecules. wha…
An attraction between the positive end of one molecule and the negative end of another molecule
-
the passage below describes an experiment. read the passage and then fo…
When sugar is added to water, does the water's temperature affect the amount of time it takes the sugar to dissolve?
-
the passage below describes an experiment. read the passage and then fo…
Does water mixed with salt evaporate faster than water mixed with sugar?
-
q1 chemistry u2l8 mastery quiz 1 practice prepwork part 1: analyze the …
1. Number of peaks in mass - spectrum of element D. 2. Tallest peak in mass - spectrum of element D. 3. Peak with highest m/z value in mass - spectrum of element D. 4. Element ide…
-
draw a resonance structure for the thiocyanate ion, scn⁻, where each at…
$S\equiv C-\ddot{N}:^{2 - }$ (with lone - pairs and formal charge shown as above)
-
module 5 quiz 2 question 13 of 13 (1 point) | question attempt: 1 of 1 …
NaF: ionic SF₆: covalent
-
part 2 of 2 identify the substances that contain discrete molecules. ch…
A. $BF_3$ B. $NO$ D. $SiCl_4$
-
classify the following substances as an ionic compound or a covalent co…
$BF_3$: covalent NO: covalent KF: ionic $SiCl_4$: covalent InP: covalent