Chemistry
Chemical reactions, stoichiometry, molecular structures, and element properties.
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question 2 of 30 if a precipitation reaction occurs, what will be the p…
C. $PbSO_4(s)+KNO_3(aq)$
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question 1 of 30 which type of molecular model shows all the atoms and …
D. Structural
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chemical company makes two brands of antifreeze. the first brand is 40%…
First brand: 150 gallons Second brand: 30 gallons
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what is one of the characteristics of the troposphere? low air pressure…
high density of air molecules
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which statement is true about the following molecule? h h c = c ch3 ch3…
It is a cis isomer.
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part c - lo 3. describe and differentiate psychological disorders, incl…
feeling extreme fatigue and irritability during the fall and winter months
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part h (8 of 8) this pair of molecules are ____. cis - trans isomers (g…
C. identical
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chemical group structure hydroxyl (may be written ho—) in a hydroxyl gr…
The amino group is most likely to gain a proton.
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a substance with a reported melting point of 134 - 136 °c melts at 128 …
The sample contains impurities
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multiple choice 1 point which factor most strongly determines the melti…
Molecular structure and crystal packing
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match each procedural step with its purpose. initial rapid heating to ~…
Initial rapid heating to ~20 °C below expected melting point: Helps estimate approximate melting range Powdering the sample: Ensures uniform heat transfer Filling only 2 - 3 mm of…
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match each compound with its correct melting point: benzoic acid benzop…
Benzoic acid: ~122°C Benzophenone: ~47°C Naphthalene: ~80°C Acetanilide: ~114°C
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complete the text with the better adverbial conjunction. one effect of …
Accordingly
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6 multiple answer 1 point which of the following statements about melti…
A. It is caused by impurities disrupting the crystal lattice. B. It depends on the number of solute particles in the molten phase. C. It can lead to a sharp eutectic temperature i…
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5 multiple choice 1 point moisture in a sample affects melting point by…
A. Causing melting point depression and broadening
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multiple choice 1 point if a mixture of benzoic acid (122 °c) and napht…
The mixture shows melting point depression
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3 multiple choice 1 point the sharp melting range of a pure solid is ty…
A. 0.5 - 2°C
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question 25 of 25 which sentence best describes what happens when a neu…
C. The protons pull harder on the remaining electrons.
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2 multiple choice 1 point which of the following best describes the ter…
The temperature at which the sample starts and finishes melting
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question 24 of 25 which molecule can form hydrogen bonds with others li…
C. $NH_3$
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the purpose of the mixed melting point test is to: purify the sample ra…
C. Identify an unknown by comparison with a known compound
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question 23 of 25 which of the following is a binary compound? a. nh4+ …
B. CaO
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question 22 of 25 which molecule or ion has a trigonal planar shape? a.…
C. $SO_3$
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question 21 of 25 what is described by the vsepr theory? a. the outside…
C. The arrangement of atoms in a molecule
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question 20 of 25 what is the correct electron configuration for an ele…
D. \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{5}\)
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question 19 of 25 how many electrons can the s orbital hold? a. 2 b. 10…
A. 2
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question 18 of 25 how does electronegativity affect the polarity of the…
B. The more electronegative atom will make its end of the bond more negative.
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question 17 of 25 which bond is a very strong dipole - dipole force? a.…
D. A hydrogen bond
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question 16 of 25 how is the atomic number related to core electrons? a…
D. The number of valence electrons plus core electrons is the atomic number.
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which situation would most likely cause a person to feel devastated? ba…
No one shows up for Joshua's thirteenth birthday party (disappointed)
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question 15 of 25 how is the oxidation state of a transition metal dete…
A. A Roman numeral placed after the transition metal identifies its oxidation state.
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question 14 of 25 what does a subscript indicate in a chemical formula?…
A. The number of atoms of that element in the molecule
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question 13 of 25 which of the following has the smallest radius? a. rb…
C. K+
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question 12 of 25 what causes a molecule to have a bent shape instead o…
D. Lone electron pairs pushing the bonding electrons out of line
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question 11 of 25 how many carbon atoms are in a molecule of table suga…
D. 12
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question 10 of 25 in which situation would hydrogen bonding be present?…
A. When hydrogen is attached to N, F, or O
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question 9 of 25 what is the correct formula for the compound formed by…
C. $Ca(NO_{2})_{2}$
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question 8 of 25 which sentence describes two atoms that form an ionic …
C. The difference in their electronegativities is greater than 1.7.
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heather tutors chemistry. for each hour that she tutors, she earns 30 d…
Equation: $A = 30H$ Amount Heather earns for 17 hours: 510 dollars
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question 7 of 25 what is the general trend in electronegativity as you …
C. Electronegativity increases.
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question 6 of 25 what kind of compounds are named using prefixes? a. tr…
C. Covalently bonded molecules
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question 5 of 25 what are orbitals? a. areas within an energy level tha…
A. Areas within an energy level that are occupied by electrons
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when dissolved in water, the chemical compound h₂so₄ releases h⁺. based…
A. an acid
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15/15 energy form characterized by the flow of electrons elastic electr…
electrical
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question 4 of 25 which term describes this molecular shape? x a x x a. …
A. Trigonal planar
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nuclear power plants start with what energy form? nuclear fission radia…
A. nuclear fission
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question 3 of 25 which of these elements has the smallest atomic radius…
D. Br
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question 2 of 25 in what order do electrons fill orbitals? a. electrons…
A. Electrons fill orbitals in order of increasing orbital energy.
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question 1 of 25 what is required for two atoms to share electrons equa…
D. The two atoms must be of the same element.
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which are true based on daltons atomic theory. select all that apply. a…
- Atoms of oxygen and those of hydrogen can combine to make water. - A piece of pure gold is made up of really small pieces called atoms. - All the atoms of a pure piece of gold a…
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energy form based on the movement of particles within an object elastic…
thermal
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question 10 of 10 when food is exposed to air, it can lose electrons. t…
A. Free radicals
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question 9 of 10 which of these is an example of food engineering? a. l…
D. Using fertilizer on crops to increase their yield
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identifying variables in a hypothesis identify the variables in this hy…
The independent variable is cigarette use. The dependent variable is lung function.
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batteries, food, and gasoline have which form of energy? chemical radia…
chemical
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question 5 of 10 which of the situations below describes an ethical dil…
A. One pesticide is used to protect a crop from being destroyed, but studies have linked it to thyroid disorders.
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light bulbs and the sun are examples of which form of energy? mechanica…
B. radiant
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a reference sample of a binary compound has a mass ratio of elements th…
191.43g Cl : 55.75g P 106.35g Cl : 30.97g P 53.2g Cl : 15.5g P
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what is energy? energy in motion the ability to do work or cause change…
the ability to do work or cause change
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talking and hearing the sound from a tv/radio are examples of which for…
C. mechanical (sound)
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3. ¿cómo es útil la densidad para identificar sustancias desconocidas?
La densidad es útil porque es una propiedad característica de cada sustancia. Al medir la masa y el volumen de una sustancia desconocida y calcular su densidad, se puede comparar …
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question 10 of 10 what determines the ratio of ions in an ionic compoun…
D. The charges on the ions
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energy form stored in bonds between atoms and molecules chemical therma…
1. chemical
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question 9 of 10 which of the following is the correct formula for copp…
D. $CuF_2$
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review the fourth paragraph. however, the science that explains why som…
It explains why some people might not enjoy roller coasters.
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however, the science that explains why some people love roller - coaste…
It explains why some people might not enjoy roller coasters.
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question 8 of 10 which of the following is the correct name for mgbr₂? …
D. Magnesium bromide
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read the text. air pressure is the pressure in a given area caused by t…
Altitude is lower, such as at sea level. - Air pressure is higher. Altitude is higher, such as at the top of Mount Everest. - Air pressure is lower.
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review the third paragraph. activities. in addition to the sense of fre…
Riding a roller coaster can give you a positive type of stress.
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question 7 of 10 which of the following is the correct formula for nitr…
A. $NF_3$
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question 6 alicia, who is a cancer patient, prefers to have her head sh…
Question 6: Personal choice Question 7: Check the client's care plan and employer's policy regarding shaving clients.
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question 6 of 10 what is the oxidation state of cobalt(iii)? a. +3 b. +…
A. +3
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the concentration in h+ of a solution can be measured using the _______…
pH
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question 5 of 10 which of the following is the correct name for ccl₄? a…
A. Carbon tetrachloride
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question 4 of 10 how are prefixes used to name compounds? a. prefixes a…
A. Prefixes are used to tell how many of each kind of atom are in covalent compounds.
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question 2 of 10 what is the oxidation number of an element? a. the gro…
B. The charge an element would have if it lost or gained electrons
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question 1 of 10 how are oxidation states of transition metals indicate…
D. Roman numerals are used to indicate oxidation states.
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question 10 of 10 what does the vsepr theory describe? a. how atomic ra…
C. Why molecules have different shapes
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question 9 of 10 nf₃ has three f atoms bonded to a central n atom, with…
B. Trigonal pyramidal
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which reference is most appropriate for handling specific chemical agen…
1. B. Safety Data Sheet (SDS) 2. B. Pharmacy Security Manual
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question 8 of 10 how does the shape of a molecule affect the polarity o…
C. A molecule that has a symmetrical shape will be a nonpolar molecule.
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question 7 of 10 what type of bonding around a central atom would resul…
C. Three groups bound to it with no lone pairs
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match each bond type with the correct description. 1 covalent 2 hydroge…
1. Electrons are shared - Covalent 2. Electrons are transferred - Ionic 3. A weak bond that occurs between atoms in polar molecules - Hydrogen
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question 6 of 10 why are a molecules atoms as far away from each other …
C. Forces between electron pairs push the atoms apart.
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question 5 of 10 what shape would a molecule with two bound groups and …
B. Bent
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question 3 of 10 which of the following shapes would represent a molecu…
D. Linear
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question 2 of 10 how does a lone pair contribute to molecular shape? a.…
B. It takes up space like an "invisible" atom.
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dr. paivio studies the ways in which the endocrine system and the nervo…
Both systems secrete molecules that activate receptors elsewhere.
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question 1 of 10 in the following ions, the first atom listed is the ce…
B. $PO_{4}^{3 - }$
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16. when burning 180 g of glucose in the presence of 192 g of oxygen, w…
264 g
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14. is a change in state a physical change or a chemical change? (0.5 p…
A. Physical change
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ag(no3)2 ag: ____ n: ____ o: ____
Ag: 1 N: 2 O: 6
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11. classify the following as either a chemical property or physical pr…
11. B. Physical Property 12. A. Intensive 13. A. Chemical change
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consider the lewis dot structures below, which represent the valence el…
C. tetrahedral
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h2o h: ____________ o: ____________
H: 2 O: 1
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na₂co₃ na: ________ c: ________ o: ________
Na: 2 C: 1 O: 3
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a lewis electron structure of a molecule is shown. judging by the elect…
$sp^{3}$
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are chemical messengers mostly manufactured by the endocrine glands, an…
Hormones
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pb(no3)2 pb: ________ n: ________ o: ________ total: ________
Pb: 1 N: 2 O: 6 Total: 9
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prelaboratory assignment 1. provide the key term that corresponds to ea…
(a) Chemistry (b) Science (c) Scientific method (d) Experiment (e) Hypothesis (f) Theory