Chemie
Chemische Reaktionen, Stöchiometrie, Molekülstrukturen und Elementeigenschaften.
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an unknown weak base with a concentration of 0.0910 m has a ph of 12.10…
\(K_b = 1.2\times10^{-3}\)
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an unknown weak base with a concentration of 0.0910 m has a ph of 12.10…
\(K_b = 1.3\times10^{-3}\)
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an unknown weak acid with a concentration of 0.089 m has a ph of 1.80. …
\(K_{a}\approx3.41\times 10^{-3}\)
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what is the ph of a 0.270 m solution of aniline (c6h5nh2, kb = 4.3 × 10…
\(9.03\)
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what is the ph of a 0.0570 m solution of hydrocyanic acid, hcn (kₐ = 4.…
\(5.28\)
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determine the concentration of hydroxide ion, oh−, in a particular solu…
The concentration of \( \text{OH}^- \) is \( 1.7\times 10^{-3}\ \text{M} \).
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as a result of an oxidation - reduction reaction, how is the oxidizing …
It gains electrons and loses potential energy.
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construct the expression for kb for the weak base, n₂h₄. n₂h₄(aq) + h₂o…
Numerator: \([OH^-][N_2H_5^+]\) Denominator: \([N_2H_4]\)
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construct the expression for ka for the weak acid, hcn. hcn(aq) + h₂o(l…
\(\frac{[H_3O^+][CN^-]}{[HCN]}\)
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the ion - product constant of water, ( k_{w} ), is ( 7.9e - 14 ) at a c…
The pH of pure water at this temperature is approximately \(6.55\).
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at 15°c, the value of ( k_w ) is ( 4.5\times10^{-15} ). what is the equ…
The equilibrium concentration of \(OH^-\) is approximately \(6.7\times 10^{-8}\text{ M}\)
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how many electrons does lithium collect in its outer shell in order to …
two
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what mass (in g) of lioh would need to be dissolved in water to make 30…
\(0.061\space g\)
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solid potassium hydroxide is dissolved in pure water, increasing the ph…
The \(OH^{-}\) concentration of the solution is approximately \(0.0132\space mol/L\)
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which of the following descriptions would be an example of potential en…
the chemical bonds in a molecule of sucrose
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the ph of an acidic solution is 5.47. what is h+?
\([H^{+}]=3.39\times 10^{-6}\space M\)
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what is the ph of a 1.5e - 4 m csoh solution?
$10.18$
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the ph of a 0.0054 m solution of hno₃ is
\(2.27\)
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which of the following statements about a system at chemical equilibriu…
The system can do no work.
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in most exergonic reactions, before products can be formed, the reactan…
activation energy of the reaction.
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the concentration of hydroxide ion in an aqueous solution at 25 °c is 2…
\(3.7\times 10^{-11}\space M\)
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compare and contrast model a with model c. how are they alike: how are …
B. They are composed of the same elements in different ratios.
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how are the properties of neon (ne) and argon (ar) similar? a both are …
A. Both are nonreactive gases at room temperature.
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i. an atom is the smallest unit of an element and a molecule is made up…
A. I & II
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sum it up! match each statement with the correct word from the word ban…
1. L. MENDELEEV 2. C. ATOMIC MASS 3. H. ATOMIC NUMBER 4. A. CHEMICAL SYMBOL 5. G. PERIODS 6. E. GROUPS 7. I. PROPERTIES 8. D. MALLEABLE 9. K. CONDUCTOR 10. J. METALLOIDS 11. F. NO…
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the periodic table is an arrangement of the chemical elements, ordered …
A. solid to gas
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what is the atomic number of this element? a 15 b 17 c 35 d 52
B. 17
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consider the elements in this family (group) of the periodic table. bec…
B. They are chemically reactive in a similar way.
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this is an ethanol molecule. the formula for ethane is ( c_2h_6o ). you…
6; 6; 12
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consider the reaction: icl(g) + cl₂(g) → icl₃(s) the δg° of the reactio…
$K_{eq} = 40.1$
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calculate \\( \\delta g^{\\circ} \\) for the reaction \\( \\mathrm{n}_{…
$$\Delta G^{\circ}=4.80\times10^{3}\text{ J/mol}$$
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c6h12o6 this is the chemical formula for a molecule of... oxygen water …
C. Glucose
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at the half - equivalence point of the first dissociation step in a dip…
...pKa1.
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how does the presence of more than one ionizable proton in a polyprotic…
Question 5: It results in multiple equivalence points. Question 6: 2 Question 7: 2
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what feature is present on a weak acid titration curve but not on a str…
Buffer region The pH remains relatively constant.
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note: the beginning of this video is the same as the video from the pre…
- **Question 1**: \(pKa\) - **Question 2**: the acid has been converted to its conjugate base
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for a strong acid - strong base titration, what is the ph at the equiva…
7
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question 3 what shape do titration curves typically have? circular zigz…
- **Question 3**: C. S - shaped - **Question 4**: B. When the moles of base equal the moles of acid
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what is the main purpose of acid - base titration? to study the solubil…
1. To determine the unknown concentration of an acid or base 2. pH vs. volume of base (or acid) added
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question 7 if ha is a stronger acid than hb, then a- is a weaker base t…
A. \(A^-\) is a weaker base than \(B^-\) ### Question 8
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the ka of an acid is ..... to the kb of its conjugate base. equal inver…
- Question 1: inversely proportional - Question 2: 14 - Question 3: By dividing \(K_W\) by \(K_a\)
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sodium + chlorine yields sodium chloride. check out the model above. wh…
C. Sodium chloride is composed of atoms.
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question 3 what are the products of a neutralization reaction between a…
Salt and water
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question 1 what happens to the concentration of hydrogen ions in a solu…
- Question 1: Increases - Question 2: Bases
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which one of the following can be used to determine the ka of a weak ac…
For the first question: pH of the weak acid. For the second question: when the change is much less than the initial concentration.
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question 5 to calculate the ph of a weak acid solution, you need to use…
an ICE box # Question 6
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question 3 why is hydrogen cyanide(hcn) a brønsted acid? hcn donates a …
HCN donates a proton ($H^{+}$ ion) to another species. # Question 4
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question 1 when a weak acid is added to water, it... ...does not dissoc…
For Question 1: "dissociates partially" For Question 2: "Hydronium ions and related anions"
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question 6 if q=k, this means that the reaction is at equilibrium. the …
the reaction is at equilibrium. # Question 7
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question 4 how can we figure out if a reaction is going to go forward o…
Question 4: compare the values of Q and K Question 5: The reaction proceeds to the right, forming more products.
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ecologist nora underwood and colleagues have examined the chemical defe…
A. deter
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when an atom gains an electron, the resulting particle is called: an an…
an anion
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part a which statement below accurately describes the contributions of …
ancient Greek philosopher who proposed that matter was not continuous
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question 8 the sum of ph and poh in any aqueous solution is equal to: 7…
14 # Question 9
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part a which of the following is not part of daltons atomic theory? all…
Most of the atom’s mass and all of its positive charge is contained in a small core called the nucleus.
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question 5 the ph of a solution is the negative logarithm of which of t…
Question 5: the concentration of hydrogen (hydronium) ions in the solution Question 6: Basic Question 7: 7
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question 3 what is the difference between an acid and its conjugate bas…
- Question 3: The presence of an extra proton in the acid - Question 4: dissociate completely in solution
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all of the following statements about different elements are true excep…
Sulfur is considered a metalloid.
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question 1 an arrhenius acid is a substance that produces which of the …
Question 1: a hydrogen ion Question 2: It is a proton acceptor
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how many protons are found in cr - 54? 64 30 24 0 none of the above
\(24\) (the third option in the given choices)
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an atom that has the same number of neutrons as $_{56}^{138}$ba is: $_{…
\(_{54}^{136}\text{Xe}\)
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what is the charge on the ion formed by selenium? 2+ 1- 2- 1+ none of t…
2 -
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what is the mass number of an ion with 108 electrons, 159 neutrons, and…
\(268\)
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part a which of the following is not a correct name, symbol combination…
iron, I
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part a what are the main ideas in the nuclear theory of the atom? check…
- The positive charge of an atom is located in the center of the atom called the nucleus, which also contains nearly all of the mass of the atom. - An atom is electrically neutral…
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what is the charge on a sulfur atom that contains 18e^- ?
B. \(2-\)
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1. name the following ionic compounds. a) naoh b) fecl3 c) fe2(so4)3 d)…
1. a) Sodium hydroxide b) Iron(III) chloride c) Iron(III) sulfate d) Zinc hydroxide e) Lead(II) oxide f) Ammonium chloride g) Tin(IV) oxide 2. a) Phosphine (or phosphorus trihydri…
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what are the properties of nonmetals? check all that apply. nonmetals a…
- First question: - Non - metals can be found as solids, liquids, or gases. - Non - metals tend to gain electrons in reactions. - Non - metals are poor conductors of heat and elec…
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part a an isotope represented as s - 34: is an isotope of sodium. conta…
none of the above
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how many electrons would be in a -2 charged anion of sulfur? 18 36 16 2…
18
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which one of the following is a main - group element? cu co ce cs none …
Cs
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6. the element helium (he) exists in the form of two stable isotopes: h…
- **Lithium - 6**: \(3\) protons, \(3\) electrons, \(3\) neutrons. - **Lithium - 7**: \(3\) protons, \(3\) electrons, \(4\) neutrons.
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poetic device options (4 of 4) rhyme scheme line break sound device ima…
- "She sells seashells by the seashore": sound device - "The fall leaves were like broken glass beneath his feet": imagery - "what if you had to go to the school dance alone?": li…
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10 que suis - je?a) nom donné aux aliments mastiqués et humidifiés par …
a) Bolus b) Déglutition c) Chyme d) Péristalse e) Segmentation
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challenge question: while traveling to a distant universe, you discover…
La masa atómica promedio del elemento \(X\) es aproximadamente \(23.45\) amu.
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6. what do you think is the closest average atomic mass for this elemen…
C. 87.6
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the two questions in the table are conceptual. 5. what do you think is …
B. 16.0
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you want to place a piece of glass tubing into a rubber stopper after t…
For the first question: D. all of the above. For the second question: any time chemicals, heat or glassware are used.
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long hair in the laboratory must be * held away from the experiment wit…
- First question: tied back or kept entirely out of the way with a hair band, hairpins, or other confining device - Second question: False
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never remove chemicals or other equipment from the laboratory * 2 point…
1. True 2. an open flame
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what potential risks are associated with consuming substances that alte…
engaging in potentially dangerous behaviors
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chipped or cracked glassware is okay to use. * true false other: return…
- "Chipped or cracked glassware is okay to use": B. False - "Return all unused chemicals to their original containers": B. False - "If a lab experiment is not completed, you shoul…
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in chapter 4, what becomes victors primary focus in his studies? (1 poi…
Discovering the secret of life and animation.
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which professor first discourages victors interest in alchemy and outda…
Professor Krempe
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what event causes victor to leave home for university at ingolstadt? (1…
His mother dies from scarlet fever.
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what subjects capture young victors interest the most? (1 point) litera…
Alchemy and natural philosophy
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what do sodium and chlorine have in common? they both have the same num…
They both have the same number of shells.
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question 2 of 13 points possible: 1.00 suppose you are working with a n…
$23.3\ mL$
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how many valence electrons does sodium have? 1 2
1
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how many energy levels does sodium have? 1 2 3
3
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austin decides to conduct a science fair experiment to investigate and …
B. Water is the best solvent and therefore must have a high polarity.
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columns on the periodic table are called... (select 2 answers) periods …
B. family, C. groups
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review question: rows on the periodic table are called groups. periods.…
periods.
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1 describe how the atomic radius(size) and the ionization energy change…
- **Within a group**: - Atomic radius increases (e.g., in Group 1, from \(Li\) to \(Fr\) new shells are added). - Ionization energy decreases (outer electrons are less tightly bou…
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1. describe how the atomic radius(size) and the ionization energy chang…
- **Atomic Radius**: - **Within a group**: Increases. For example, in Group 1, \(Li < Na < K\). - **Within a period**: Decreases. - **Ionization Energy**: - **Within a group**: De…
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the table below gives information about two isotopes of element y. 1. 3…
The average atomic mass of element \(Y\) is \(20.18\)
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for any chemical process in an isolated system in which all reactants a…
A. Equal to
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2. describe the property of water that is indicated by the data. how is…
The sand would feel warmer. Water has a high specific heat capacity due to the hydrogen bonds between its molecules. It takes more energy to raise the temperature of water compare…
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the kinetic theory model states that particles of matter are always in …
Gas
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condensation is when a gas loses energy and becomes a liquid. when a ga…
The particles slow down.