Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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what separation technique is illustrated in the picture? evaporation de…
evaporation
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what technique effectively separates mixtures of liquids that have diff…
distillation
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distillation of wintergreen mouthwash heat is applied gently to a solut…
wintergreen
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distillation of cherry-vanilla cola heat is applied gently to a solutio…
D. the sugar remaining in the flask
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water and alcohol are two liquids that mix completely but can be separa…
D. boiling point
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vinegar and water are liquids that mix completely together. which techn…
distillation
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based on the order the substances come out of the distillation, which s…
B. the vanilla ester
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which of these mixtures would best separate using distillation? solid s…
honey and tea
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what method is used to separate molecules of different polarities or at…
chromatography
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according to this chromatography strip, which dye color is most similar…
the red dye
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what separation technique is illustrated in the picture? decantation ch…
chromatography
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what separation technique is illustrated in the picture? options: filtr…
distillation
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determine which factors will increase the reaction rate and which facto…
Increase Reaction Rate: Increase temperature Increase surface area Add a catalyst Decrease Reaction Rate: Decrease concentration Decrease temperature Decrease surface area
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a dilute solution of water and milk is prepared. when tested, the solut…
colloid
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classify the following as a heterogeneous mixture (suspension), homogen…
homogeneous mixture (solution)
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classify the following as a heterogeneous mixture (suspension), homogen…
homogeneous mixture (solution)
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classify the following as a heterogeneous mixture (suspension), homogen…
colloid
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classify the following as a heterogeneous mixture (suspension), homogen…
colloid
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classify the following as a heterogeneous mixture (suspension), homogen…
heterogeneous mixture (suspension)
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what term describes two or more substances that are physically but not …
mixture
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compare the total mass of the reactants to the total mass of the produc…
A. $30\ \text{g}\ \text{Li}_2\text{O} + 44\ \text{g}\ \text{CO}_2 ightarrow 74\ \text{g}\ \text{Li}_2\text{CO}_3$
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what mass of product is formed during the reaction in the graphic below…
16.25 g
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what mass of product is formed during the reaction in the graphic below…
16.25 g
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compare the total mass of the reactants to the total mass of the produc…
B. $28\ \text{g}\ \text{N}_2 + 6\ \text{g}\ \text{H}_2 ightarrow 34\ \text{g}\ \text{NH}_3$
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compare the total mass of the reactants to the total mass of the produc…
B. $102\ \text{g S} + 102\ \text{g O}_2 ightarrow 204\ \text{g SO}_2$
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based on the law of conservation of mass, what mass of product is forme…
55.12 g
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29/50 how many atoms are present if there is no subscript following the…
only 1
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how do the following two elements bond together? k⁺ s²⁻
$K_2S$ (the yellow-green bottom option)
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what element should always be in the center of a lewis dot structure? t…
The central atom should be the least electronegative element, or Carbon
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30 a piece of silver is measured to have a mass of 26.25 grams. its vol…
The density of the piece of silver is $10.5$ grams per cubic centimeter (or $10.5$ $g/cm^3$).
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28 all substances have the same melting point. true or false? propertie…
False
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23 is the ability to rust a physical or chemical property?
The ability to rust is a chemical property.
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part d: transition metals – thinking with roman numerals 7. write the s…
$\boldsymbol{Fe^{3+}}$ #### Copper (I)
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16/50 how many sodium atoms are in 6nacl?
6
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part b: electrons & charge reasoning 3. complete the table below. ion \…
### Question 3: Complete the table To complete the table, we use the atomic number (number of protons) and the charge to find the number of electrons. The net charge is calculated…
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part a: valence & ion prediction use the periodic table to answer the f…
### Question 1: Valence Electrons Calculation #### Step 1: Sodium (Na) - **Explanation**: Sodium is in Group 1 of the periodic table. For main - group elements, the number of vale…
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practice 14. complete the table. the first row is done for you. | ion n…
### Question 15 (Writing symbol and charge for transition metal ions) #### Step 1: Cobalt (II) The Roman numeral (II) indicates the charge is +2. The symbol for cobalt is Co. So t…
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which of the following is a compound? \\(\\ce{co2}\\) \\(\\ce{c}\\) \\(…
$\text{CO}_2$
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how do the following two elements bond together? al³⁺ o²⁻ options: alo,…
$\text{Al}_2\text{O}_3$ (the purple option)
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daoists seek harmony for confucius, the social order of family and gove…
4. The main beliefs of Daoists are: - A universal force called the Dao (the Way) guides all things. - People should seek order and live in harmony with nature, following the examp…
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when magnesium (mg) is bonding with oxygen (o), what kind of charge wil…
+2
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what is the lewis dot structure for a neutral atom of carbon (₆c)? the …
The element symbol C with 4 dots around it.
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what is the lewis dot structure for a neutral atom of sodium (₁₁na)? th…
The element symbol Na with 1 dot around it.
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what is the percent of oxygen by mass in a pure sample of fecr₂o₄? 1. 5…
5. 29%
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what is the volume of 1.56 kg of a compound whose molar mass is 81.86 g…
6. 37.9 mL
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calculate the number of carbon atoms in 0.75 l of acetone (ch₃coch₃). (…
4. \( 3.0 \times 10^{25} \) atoms
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how many moles of caco₃ would contain 14.5 g of oxygen atoms? 1. 0.302 …
2. 0.0716 mol
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6. molar mass 01 10 pts possible find the molar mass of pb(no₃)₂. answe…
331.22
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which of the following would contain the largest number of moles? 1. 5.…
5. 5.00 grams of lithium (Li)
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six moles of toluene are combined with two moles of benzene. what is th…
4. 0.25
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the total number of electrons in one mole of fluorine molecules (f₂) is…
4. \( 18 \times 6.0 \times 10^{23} \)
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u4g6 what is the molar mass of sodium? be sure to include units written…
22.99 g/mol (or 23.0 g/mol, depending on precision; the exact molar mass of sodium is approximately 22.99 g/mol)
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3. molar mass 10 pts possible find the molar mass of c₂h₅cooh. answer i…
$74.08$ (rounded to two decimal places, or $74.078$)
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anwar al - sadat and menachem begin won the nobel peace prize in 1978 f…
signing the Camp David Accords.
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2/50 which of the following is not an ionic compound: br₂ naoh cao bacl₂
$\text{Br}_2$
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is the molecule overall polar or nonpolar? options: nonpolar, polar
Polar
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is the molecule overall polar or nonpolar? polar nonpolar (with the mol…
Nonpolar
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3. compare the total number of valence electrons in each compound befor…
1. Ionic bonds form between metals and nonmetals; covalent bonds form between nonmetals (or metalloids and nonmetals). 2. Ionic bonds transfer valence electrons; covalent bonds sh…
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part 2: covalent bonding: follow the instructions and record your data …
1. Valence electrons are shared: some form shared bonded pairs between atoms, while others stay as unshared lone pairs on each atom, to fill each atom's valence shell for stabilit…
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question 5 how is molecular formula related to empirical formula? one v…
It can be equal but it is usually a simple integer multiple of the empirical formula ### Question 6
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question 3 1 pts how is an empirical formula calculation related to a p…
B. They are exactly the reverse of each other in terms of math steps ### Question 4
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question 1 1 pts what is the ratio of atoms in the compound hcl? 1 to 3…
1 to 1 ### Question 2
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which describes a climate effect on the rate of weathering? ○ cold clim…
A. Cold climates favor mechanical weathering.
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organic material provides nitrogen for plants. which soil component con…
B. humus
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question 7 diatomic elements are important. what makes them different f…
B. The atoms are found in pairs in nature. ### Question 8
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if there are $12 \\times 10^{23}$ oxygens in a sample of water, how man…
s: First Question (Hydrogen in water):
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5 zinc reacts with copper(ii) chloride to give copper metal and a solut…
### Question 5: $\boldsymbol{\text{Zn (s)}} + \boldsymbol{\text{CuCl}_2 \text{ (aq)}} ightarrow \boldsymbol{\text{Cu (s)}} + \boldsymbol{\text{ZnCl}_2 \text{ (aq)}}$ ### Question …
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6. explaining why salts used in food processing tend to be hard solids …
Salts used in food processing are ionic compounds with a tightly bound ionic lattice held by strong coulombic attractions between oppositely charged ions. This strong, ordered ion…
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name directions: answer the questions based on the clusters on chemical…
1. b) Long chains of atoms bonded together within each molecule 2. | Substance | Type of Bonding (Ionic or Covalent) | Evidence | |-----------|------------------------------------…
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procedure: using your computer, tablet or mobile device, navigate to th…
1. Sodium (Na) a. Alkali Metal (Group 1 Metal) b. 1 2. Fluorine (F) a. Halogen (Group 17 Nonmetal) b. 7 3. Ionic bond 4. Lewis Dot Diagrams: - Na: $\ce{Na \cdot}$ [LLM SSE On Fail…
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1.16-chem review when smaller atoms combine to create a new larger atom…
C. Nuclear fusion
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stomach acid ph= 1 ☐ neutral ☐ basic vinegar ph= 3 ☑ acidic ☐ neutral ☐…
### Corrected pH Category Assignments: 1. Stomach Acid (pH=1): ☑ Acidic, ☐ Neutral, ☐ Basic 2. Vinegar (pH=3): ☑ Acidic, ☐ Neutral, ☐ Basic 3. Water (distilled) (pH=8): ☐ Acidic, …
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1.16-chem review protons and neutrons make up the mass of a nucleus. tr…
True
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1.16-chem review electrons have low to no mass. true false
True
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saliva ph=7 acidic neutral basic shampoo ph=7 acidic neutral basic stom…
| Substance | pH Value | Classification | |---------------------|----------|----------------------| | Saliva | 7 | Neutral | | Shampoo | 7 | Neutral | | Stomach Acid | 1 | Acidic …
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introduction: lab #14: ionic and covalent bonds (holiday) atoms form bo…
The dot in the Lewis dot diagram of lithium represents its **valence electron** (specifically, the 1 electron in its outermost (valence) energy level).
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lemon juice ph= acidic neutral basic orange juice ph= acidic neutral ba…
1. Lemon Juice: pH=2, ☑ Acidic 2. Orange Juice: pH=3, ☑ Acidic 3. Tomato Juice: pH=4, ☑ Acidic 4. Milk: pH=6.5, ☑ Acidic (slightly acidic) 5. Milk of Magnesia: pH=10, ☑ Basic 6. O…
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what is the density of the object, reported to two significant figures?…
$1.8\ \frac{\text{g}}{\text{mL}}$
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how many significant figures should the answer be reported with? \\(\\f…
2 significant figures
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how many significant figures are in the measurement 9.1 ml? 9.1 ml has …
2
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identify the ph of each substance. then, classify them as acidic, neutr…
| Substance | pH | Classification | |-----------------|-----|----------------| | Ammonia | 11 | Basic | | Baking Soda | 9 | Basic | | Bleach | 13 | Basic | | Coffee | 5 | Acidic |…
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how many significant figures are in the measurement 16.400 g? 16.400 ha…
5
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frequency and he found that this frequency was mathematically related t…
Yes, there were problems with Mendeleev’s Periodic Table. - **Atomic Mass - based Arrangement Exceptions**: Elements were arranged by atomic mass, but some elements (e.g., telluri…
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elements every element has a unique atomic number which indicates the t…
12 (for Magnesium, neutrons ≈ 12) If the question was different (e.g., identifying the element), the answer would be Magnesium (Mg), atomic number 12. Please clarify the exact que…
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who created the first periodic table of elements? identify the two char…
1. Atomic Mass (from the numbers in parentheses for each element). 2. Chemical Properties (from oxide formulas, e.g., \( R_2O \), \( RO \), \( R_2O_3 \), etc., showing similar rea…
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find argon on the periodic table and provide the number of protons, neu…
18 protons, 18 electrons, 22 neutrons
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the more density an object has, the more likely it is to______ in water…
1. Sink 2. Products
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purpose: to determine the trends of the periodic table relating to atom…
### Data Analysis 1 (Trends Across a Period and Down a Group) #### Across a Period (→) - **Atomic Radius**: As you move from left to right across a period, the atomic radius tends…
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multiple choice question weight, height, skinfold thicknesses, and body…
O anthropometric
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the number of valence electrons an element has determines not only what…
To solve this, we analyze the group behavior of each element: ### Part a: Ca (Calcium) Calcium is in Group 2 (alkaline earth metals). Elements in the same group have similar chemi…
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using the periodic table to identify number of valence electrons and th…
(for Group 1A as an example): - Valence Electrons: 1 - Ion Charge: \( +1 \) (You can follow the same logic for other groups. If you want a specific group's answer, just specify th…
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21. which element is the most reactive in the... a. alkali metals? b. a…
Noble gases have a full valence electron shell (e.g., octet configuration, or 2 electrons for He). This stable electron arrangement means they do not need to gain, lose, or share …
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limiting reactant - regular problem 9.23 for each of the following reac…
$\text{O}_2$
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problem 9.23 for each of the following reactions, 28.0 g of each reacta…
$31.1\ \text{g}$
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early earth: 1st half - place in the correct order (oldest to youngest.…
Oldest (top) to Youngest (bottom): 1. - molten surface constantly bombarded by asteroids and planetesimals, keeping temperatures so hot that rock remained liquid because the kinet…
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the ideal gas equation is $$pv = nrt$$ where $p$ is pressure, $v$ is vo…
- Convert the pressure to atmospheres (atm) - Convert the volume to liters (L)
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the equation for molarity, m, is where v is volume and n is the number …
6.51 mol (rounded to three significant figures, consistent with the given values)
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you do not need any science knowledge to perform the following calculat…
$2.28$ $\text{g/cm}^3$
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going from a decimal to a percentage as you saw in the previous parts, …
12.8
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name homework unit 8 mixed practice complete each step for all of the f…
### Question 1: Dicarbon hexahydride reacts with oxygen gas to produce carbon dioxide and water #### Step 1: Translate to chemical equation Dicarbon hexahydride is \( \ce{C2H6} \)…