Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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17 classify the following as a physical property or a chemical property…
physical property
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16 by what method could you use to separate the components of ink? * (0…
Paper Chromatography (or Chromatography)
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perform the calculation to the correct number of significant figures. 0…
121.0
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perform the calculation to the correct number of significant figures. 3…
\( 0.381 \)
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11 what kind of mixtures are pictured here? * (0.5 points) enter your a…
Homogeneous (or Solution) ### Question 12
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9 a student performs an experiment to measure the boiling point of pent…
3.05%
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8. butter melts and burns in a hot frying pan. which of these changes i…
- Melting of butter is a physical change (as it involves a change in state without altering the chemical composition of butter). - Burning of butter is a chemical change (as it in…
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each of the following statements about carbon is true except which one?…
Carbon can form strong hydrogen bonds with other elements.
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part c what determines the types of chemical reactions that an atom par…
the number of electrons in the outermost electron shell
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part b which of these relationships is true of an uncharged atom? optio…
The number of protons is equal to the number of electrons.
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part a molecules such as water are referred to as ____ because they are…
A. polar molecules
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what are the molecular and empirical chemical formulas of a compound ma…
Molecular formula: $\boldsymbol{C_2H_4O}$; Empirical formula: $\boldsymbol{C_2H_4O}$
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how is a poems rhyme scheme marked and identified? upper or lowercase l…
A. upper or lowercase letters, such as "ABAB"
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compound | sketch of molecules in it | group a | h—c≡c—o—h | select (gr…
To solve this, we analyze the molecular structures: ### Compound A The structure is \( \ce{H - C\equiv C - O - H} \) (ethynol). It has a triple bond (\( \ce{C\equiv C} \)) and a h…
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sort the molecular compounds in the table into groups with the same emp…
To solve this, we first need the molecular formulas of all compounds (but since only Compound A is shown here, we assume we need to analyze its empirical formula. However, the pro…
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what are the molecular and empirical chemical formulas of a compound ma…
# Explanation: ## Step1: Count the number of each atom First, we count the number of carbon (C), hydrogen (H), and oxygen (O) atoms in the molecule. - Carbon (C): Let's look at th…
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part a when sugar is dissolved in water, sugar is the ______ and water …
solute; solvent
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part e consider two solutions. solution a has a ph of 2, and solution b…
Solution A is 100 times more acidic than solution B.
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drag the appropriate items to their respective bins. view available hin…
Homogeneous mixture: rum, bronze, honey Heterogeneous mixture: pizza, gravel
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part d when comparing an acid and a base, which statement is true? an a…
An acid has a higher concentration of hydrogen ions and a lower pH than a base. (The option with this description, likely the second option in the list provided in the problem's c…
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une solution dacide sulfurique (h₂so₄) a une concentration de 49 g/1,2l…
D. 0,42 mol/L
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blue vitriol is commonly used in industrial dyeing processes. what is t…
$\boldsymbol{CuSO_4}$
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complete the table below, using the diagram of an atom shown at right. …
| name | symbol | charge (in multiples of e) | approximate mass (amu) | location on diagram | |-----------|--------|----------------------------|------------------------|---------…
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complete the table below, using the diagram of an atom shown at right. …
To solve this, we recall the properties of subatomic particles: ### First Row (Neutron): - **Name**: Neutron (symbol \( \ce{_n^0} \)) - **Charge**: Neutrons have no charge, so \( …
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complete the table below, using the diagram of an atom shown at right. …
| name | symbol | charge (in multiples of \( e \)) | approximate mass (amu) | location on diagram | |-----------|--------|----------------------------------|----------------------…
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fahrenheit 451 – reading assignment 6 analysis questions for pages 76-8…
Montag says his wife is dying because Mildred is emotionally and spiritually vacant. She is consumed by the parlor walls (TV - like devices) and lacks real human connection or dep…
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fahrenheit 451 – reading assignment 6 analysis questions for pages 76-8…
Montag says "My wife’s dying" to Faber because Mildred is spiritually and emotionally lifeless. She is consumed by shallow, mind - numbing entertainment (like her parlor - wall "f…
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complete the table below, using the diagram of an atom shown at right. …
To solve this, we recall properties of subatomic particles: ### Step 1: Identify the first particle (charge 0, mass ~1 amu, location A) This is a **neutron**? Wait, no—wait, charg…
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read each description in the first column of the table below. if any ch…
To solve this, we analyze each description using the periodic table (elements with atomic number \( Z \leq 92 \)): ### 1. An element in Period 5 and Group 6A - **Step 1**: Recall …
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using the rules for naming molecular compounds described in the introdu…
Nitrogen dioxide ### Part B
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decide which element probably has a boiling point most and least simila…
Most similar to calcium: magnesium Least similar to calcium: argon
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decide which element probably forms a compound with hydrogen that has a…
- Most similar to oxygen: sulfur (select the radio button for sulfur in the "most similar to oxygen" row) - Least similar to oxygen: potassium (select the radio button for potassi…
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write the chemical formula for this molecule: drag the slider to get a …
\( \text{CH}_4\text{S} \) (or \( \text{CH}_3\text{SH} \))
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write the chemical formula for this molecule: drag the slider to get a …
$C_2H_4O_2$
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write the chemical formula for this molecule:
$\boldsymbol{C_3H_6O_2}$
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fill in the missing information: | symbol | atom or ion? (check all tha…
| symbol | atom or ion? (check all that apply) | number of protons | number of electrons | |--------|--------------------------------------|-------------------|-------------------…
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after watching a show about submarines, jamil wants to learn more about…
D. What substances dissolve in ocean water?
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match each diagram to the atom or ion it represents. drag each item to …
- P: Diagram with \(15^+\) and \(15^-\) - \(P^{3+}\): Diagram with \(15^+\) and \(12^-\) - \(P^{3-}\): Diagram with \(15^+\) and \(18^-\) - Mg: Diagram with \(12^+\) and \(12^-\) …
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fill in the missing information: table with columns: symbol, atom or io…
### For $\boldsymbol{\ce{Mg^{2+}}}$: ## Step1: Determine type (cation) $\ce{Mg^{2+}}$ has a positive charge, so it's a cation (not neutral atom or anion). ## Step2: Find protons (…
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which of the following elements is not a metal? view available hint(s) …
D. phosphorus ### Second Question (Which of the following is not an element?):
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what is the atomic number of the element located in group 16, period 2 …
8 ### Part B
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classify the following elements as metal, nonmetal, or metalloid (semim…
- Metal: Mn, Na - Nonmetal: Xe, S - Metalloid: Ge, As
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elements: w, sr, h, ti, be, si, fr; periods: period 1, period 2, period…
Period 1: H Period 2: Be Period 3: Si Period 4: Ti Period 5: Sr Period 6: W Period 7: Fr
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fill in the missing information! | symbol | atom or ion? check all that…
s for each missing cell: - First row protons: $\boldsymbol{5}$, electrons: $\boldsymbol{3}$ - Second row symbol: $\boldsymbol{\text{Mg}}$, protons: $\boldsymbol{12}$ - Third row s…
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classify the following elements as halogens, alkali metals, alkaline ea…
- Halogens: Br, F - Alkali metals: Li, K - Alkaline earth metals: Sr - Noble gases: Ar
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classify the following elements as main group elements, transition meta…
- Main group elements: P, Pb, Ba - Transition metals: Fe, Pt - Inner transition metals: Th
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12. consider the following three step mechanism: cl₂(g) ⇌ 2 cl(g) fast …
Overall reaction: $\boldsymbol{\ce{Cl2(g) + CHCl3(g) -> HCl(g) + CCl4(g)}}$ ### Part 2: Identify Intermediates
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a certain element x has four isotopes. - 94.93% of x has a mass of 31.9…
S
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12. consider the following three step mechanism: $ce{cl2(g) <=> 2 cl(g)…
s: - **Overall Reaction**: $\boldsymbol{\ce{Cl_{2}(g) + CHCl_{3}(g) ightarrow HCl(g) + CCl_{4}(g)}}$ - **Intermediates**: $\boldsymbol{\ce{Cl(g)}}$ and $\boldsymbol{\ce{CCl_{3}(g)…
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part c what is the identity of element x from part b? express your answ…
### Part C To determine the identity of element \( X \), we typically use the atomic number (the subscript in the isotope notation \( _Z^A X \), where \( Z \) is the atomic number…
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part b a certain element x has four isotopes. - 94.93% of x has a mass …
32.07
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how many neutrons are found in one atom of ( ^{16}\text{n} )? express y…
9
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what is the relative atomic mass of the element that consists of the fo…
58.7 amu
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what is the relative atomic mass of a hypothetical element that consist…
Value: $89.8$, Units: amu
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give the nuclear symbol for the isotope of argon for which ( a = 38 )? …
$\ce{_{18}^{38}Ar}$
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part d an atom of sulfur is represented by $\\ce{^{33}_{16}s}$. how man…
17 ### Part E
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part b the atomic number of fluorine is 9. what is the mass number of a…
17 ### Part C
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the atomic number z is the number of protons in the nucleus of an atom …
proton, neutron
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food safety many people often ask, \how do i know if foods in the freez…
keep food safe for longer periods
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food safety many people often ask, \how do i know if foods in the freez…
First dropdown: how freezing food
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2. explica por qué la masa permanece constante en una reacción química.…
### Pregunta 2: # Breve Explicación: La ley de conservación de la masa establece que en una reacción química, los átomos no se crean ni destruyen, solo se reorganizan. Esto signif…
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6 sur 32 lors dune neutralisation, 30 ml dune solution de h₂so₄ ont neu…
E. 0,15 mol/L
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respuesta corta: 1. describe cómo se aplica la conservación de la masa …
Al derretirse el hielo (cambio de estado de sólido a líquido), la masa se conserva: la masa del hielo original es igual a la masa del agua resultante, ya que las moléculas de H₂O …
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2. en un ______ cambio, la apariencia de la sustancia puede cambiar, pe…
### Pregunta 2: # Breve Explicación: En química, un cambio físico es aquel en el que la sustancia no pierde su identidad química, solo su apariencia (como estado de agregación, fo…
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2. en un ____ cambio, la apariencia de la sustancia puede cambiar, pero…
### Pregunta 2: # Breve Explicación: En un cambio **físico**, la apariencia de la sustancia puede cambiar, pero su identidad (la naturaleza química de la sustancia) permanece igua…
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completa los espacios: 1. según la ley de conservación de la masa, la m…
destruida
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dans la réaction suivante : 2 al + 3 cl₂ → 2 alcl₃ calculez la masse de…
C. 266 g
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emparejamiento: preguntas | opciones de respuesta 1. ley de conservació…
To solve this matching problem, we analyze each question and option: ### 1. Ley de Conservación de la Masa The Law of Conservation of Mass states that matter is neither created no…
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preguntas de opción múltiple: 1. ¿qué establece la ley de conservación …
b) La masa no es creada ni destruida ### Pregunta 2
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4 sur 32 calculez la masse de 2 moles de dioxyde de carbone (co₂). 2 po…
D. 88 g
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3 sur 32 dans la réaction suivante : caco₃ + 2 hcl → cacl₂ + co₂ + h₂o …
C. 1 mol/L
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sugar will take less time to dissolve in: ○ ice cold lemonade ○ iced te…
hot cup of coffee ### Second Question (Diffusion Rate):
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an example of an atom that has no charge is one that has a) 2 protons, …
A) 2 protons, 2 electrons, and 1 neutron.
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2 sur 32 vous avez 98 g d’acide sulfurique (h₂so₄). calculez le nombre …
D. 1 mol
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graded qu... 0:10:01 elapsed which nonmetal makes up diamond, graphite,…
D) Carbon
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une solution de sulfate de cuivre (cuso₄) a une concentration de 1,2 mo…
E. 0,5 mol
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which statement is true about alkali metals? a) they arent very reactiv…
C) Some of them explode when exposed to water.
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the purpose of an indicator is to a) test and determine the ph values o…
A) test and determine the pH values of unknown solutions.
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preguntas: 1. ¿por qué parece que la vela pierde masa, aunque no lo hac…
### Pregunta 1 # Breve Explicación: Cuando una vela arde, el cera reacciona con el oxígeno del aire en una reacción de combustión, produciendo dióxido de carbono ($\ce{CO_2}$) y v…
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which classification of matter includes materials that can no longer be…
A) Compound
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the valence of aluminum is +3, and the valence of chlorine is −1. the f…
C) \(Cl_{3}Al\)
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whats the percent composition of sulfur in h₂so₄? a) 2.1% b) 65.2% c) 3…
C) 32.7%
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a chemical reaction in which two elements or radicals change places wit…
A) double replacement
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a chemical reaction in which two or more substances undergo a chemical …
(Assuming the correct option, say if there was a C) synthesis, then C. But since the visible options don't have it, there's an error. However, if we assume a misprint and the inte…
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the molecular mass of sodium oxide (na₂o) is a) 61.97894. b) 45.97954. …
A) 61.97894
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the smallest unit of an element that has all of the properties of the e…
B) atom.
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all of the following are assumptions presented by daltons atomic theory…
A) all atoms of different elements are alike in size, shape, and weight.
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8. the reaction a → products is first order in a. if 1.60 g of a is all…
The half - life of the reaction is $\boxed{22.5\ min}$
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organic chemistry is the study of compounds containing a) carbon. b) ni…
A) carbon.
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regarding the formula al₂o₃ which of the following is accurate? a) the …
Option A is inaccurate (as subscript 2 in $\ce{Al_{2}O_{3}}$ represents 2 Al atoms, not 2 O atoms). If we assume we need to state the accuracy of A, the answer is that A is incorr…
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which of the following chemical equations is balanced? a) nh₃ + h₂o → 2…
There is an error in the given options as none of the provided chemical equations are balanced. However, if we assume possible typos: - If option B was \(2NaCl + H_2SO_4 \to 2HCl …
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graded qu... x 0:00:15 elapsed which of the following formulas represen…
C) \( C_2H_4 \)
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what product is formed in the hydration reaction shown below? chemical …
The first option (the structure with \(OH\) on the tertiary carbon, i.e., the first circular - option structure) ### Second Question (Unsaturated Hydrocarbon)
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check the box under each compound that exists as a pair of cis/trans is…
We check the box under the compound $\boldsymbol{\ce{HO - CH = CH - OH}}$. If none of the compounds had met the criteria, we would check "none of the above", but in this case, $\c…
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which term correctly describes the relative position of the two substit…
ortho ### Second Question (Cis - Trans Isomerism)
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a cyclic alkene with ch₃ group + h₂ (pd catalyst) → options: (1) cycloh…
The second option (the structure with a cyclohexane ring and a \( - CH_3\) group attached) ### Question 11 (IUPAC Naming of Alkene)
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agrocybin is isolated from edible mushrooms and is reported to be an an…
s: (1) \( 109.5^\circ \) (2) \( 180^\circ \) (3) \( 180^\circ \) (4) \( 120^\circ \)
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what is the iupac name of this compound? h₃c | c=c | | h h ch₂ch₃ optio…
B. cis - 2 - pentene
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15 déterminez la formule chimique des composés formés à partir des subs…
To determine the chemical formula of the compound formed, we use the **cross - multiplication method** (also known as the criss - cross method) for the positive and negative ions.…
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la concentration 19 remplissez le tableau ci-dessous. soluté | masse du…
To solve for the missing values in the table, we use the formulas for concentration: ### 1. For $\boldsymbol{\ce{Na3PO4}}$: #### Step 1: Concentration (g/L) Concentration (g/L) = …