化學
化學反應、化學計量、分子結構與元素性質。
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aktiv will undergo scheduled maintenance on oct 19 from 5am to 8am et. …
\(2Cr(s)+3I_2(s)\to 2CrI_3(s)\)
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question 26 of 37 balance the following chemical equation (if necessary…
\(MnO_2(s)+4HCl(aq) ightarrow MnCl_2(aq)+2H_2O(l)+Cl_2(g)\)
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question 25 of 37 balance the following chemical equation (if necessary…
\(2C_6H_6(l)+15O_2(g)\to 6H_2O(g)+12CO_2(g)\)
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question 24 of 37 balance the following chemical equation (if necessary…
\(4Si_2H_3(s)+11O_2(g)\to8SiO_2(g)+6H_2O(g)\)
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question 23 of 37 balance the following chemical equation (if necessary…
\(2Li_2Se(s)+SO_2(g)=SSe_2(g)+2Li_2O(s)\)
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question 22 of 37 balance the following chemical equation (if necessary…
\(2BF_3(s)+3Li_2SO_3(s)\to 6LiF(s)+B_2(SO_3)_3(s)\)
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question 21 of 37 balance the following chemical equation (if necessary…
\(V_2O_5(s)+6HCl(aq)\to2VOCl_3(s)+3H_2O(l)\)
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balance the following chemical equation (if necessary): v₂o₅(s) + hcl(a…
\(V_{2}O_{5}(s)+10HCl(aq) = 2VOCl_{3}(s)+5H_{2}O(l)\)
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what is the coefficient in front of the o₂·when the equation below is b…
7
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balance the following chemical reaction: al₂(so₄)₃(aq) + k₃po₄(aq) → al…
A. \(Al_2(SO_4)_3(aq)+2K_3PO_4(aq)\to 2AlPO_4(s)+3K_2SO_4(aq)\)
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write a balanced chemical equation based on the following description: …
\(K_{2}O(s)+H_{2}O(l)=2KOH(aq)\)
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write a balanced chemical equation based on the following description: …
\(Mg(s)+Cl_{2}(g)\to MgCl_{2}(s)\)
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write a balanced chemical equation based on the following description: …
\(C_4H_{10}O(s)+6O_2(g)\to4CO_2(g)+5H_2O(g)\)
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write a balanced chemical equation based on the following description: …
\( \text{BaCO}_3(s)\xrightarrow{\text{heat}}\text{BaO}(s)+\text{CO}_2(g) \)
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balance the following chemical equation (if necessary): na_{3}po_{4}(aq…
\(2Na_3PO_4+3NiCl_2 = Ni_3(PO_4)_2+6NaCl\)
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balance the following chemical equation (if necessary): pbco₃(s) → pbo(…
The chemical equation \(PbCO_{3}(s) ightarrow PbO(s)+CO_{2}(g)\) is already balanced.
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magnesium metal, a gray solid, is heated in a crucible in the presence …
A. a chemical change
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problem 7 of 37 answer: a fe₂s₃(s) + hcl(g) → fecl₃(s) + h₂s(g) b fe₂(s…
C. $\text{Fe}_2\text{S}_3(\text{s})+6\text{HCl}(\text{g})\to2\text{FeCl}_3(\text{s}) + 3\text{H}_2\text{S}(\text{g})$
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write a balanced chemical equation based on the following description: …
\(2Al(s)+Fe_2O_3(s)\to Al_2O_3(s)+2Fe(l)\)
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write a balanced chemical equation based on the following description: …
\(2C_{3}H_{7}OH(l)+9O_{2}(g)\to6CO_{2}(g)+8H_{2}O(g)\)
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write a balanced chemical equation based on the following description: …
\(2AgNO_3(aq)+NiCl_2(aq)\to 2AgCl(s)+Ni(NO_3)_2(aq)\)
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aktiv will undergo scheduled maintenance on oct 19 from 5am to 8am et. …
\(4NH_3(g)+5O_2(g)\to4NO(g)+6H_2O(g)\)
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click to fix any capitalization errors below. click \submit answer\ if …
Ravi Ross looks forward to performing many explosive chemistry experiments this year.
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question 2 (0.5 points) ✓ saved listen the correct names of pbcl₄ and n…
2) Lead(IV)chloride and Nickel(II)Bromide
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question 1 (0.5 points) ✓ saved listen the correct formulas for iron(ii…
4) \(Fe_{2}S_{3}\) and \(Co_{3}P_{2}\)
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question 11 (1 point) listen the correct formulas for beryllium sulfide…
1) \(BeS\) and \(Li_{3}P\)
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question 10 (1 point) listen the correct names of fe₃(po₄)₂ and zn(no₃)…
2) Iron(II)Phosphate and Zinc nitrate
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question 9 (1 point) listen the correct formulas for chromium(iii)oxide…
1) \(Cr_{2}O_{3}\) and \(AlPO_{4}\)
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question 8 (1 point) listen the correct names of the acids hcl and hco3…
1) Hydrochloric acid and Carbonic acid
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question 7 (1 point) listen the correct names of the acids hno₃ and h₂s…
3) Nitric acid and Hydrosulfuric acid
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question 6 (1 point) listen the correct names for n₂o₅ and no₂ are: 1) …
2) diNitrogen pentoxide and Nitrogen dioxide
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question 5 (1 point) listen the correct names of ca3n2 and ba3n2 are: 1…
3) Calcium nitride and Barium Nitride
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question 4 (1 point) listen the correct formulas for ammonium sulfate a…
2) \((NH_4)_2SO_4\) and \(NH_4C_2H_3O_2\)
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question 3 (1 point) which of the following is correct? 1) s₈ is an ato…
3) \(O_2\) is a molecular element.
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question 2 (0.5 points) listen the correct names of pbcl4 and nibr2 are…
2) Lead(IV)chloride and Nickel(II)Bromide
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station 4 chemical formulas which compound contains the most number of …
G. Propane
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station 4 chemical formulas which of the following contains the most nu…
C. Baking Soda
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multiple - choice question how much liquid is in this 100 ml graduated …
74 mL
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what is the volume of the water in this 10 ml graduated cylinder? 6.4 m…
\(6.6\) mL (corresponding to the option \(6.6\space mL\))
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station 3 mixtures which of the following are not ways to separate mixt…
D. all the above can separate mixtures
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station 3 mixtures which of the following forms a heterogenous mixture?…
A. cereal and milk
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what is a mixture that looks like a single substance and has the same p…
A. solution
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station 3 mixtures which of the following is true about mixtures? a. mi…
B. Substances in mixtures keep their unique properties.
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station 2 elements and compounds what two elements are found in table s…
B. Sodium and Chlorine
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station 2 elements and compounds which of the following is a compound? …
A. sugar
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station 2 elements and compounds two or more elements bonded together c…
C. compound
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station 2 elements and compounds which of the following is not true abo…
D. Elements are the building block of matter.
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a geochemist in the field takes a 14.0 ml sample of water from a rock p…
yes, \(0.023\space g/mL\)
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a chemistry student is given 3.00 l of a clear aqueous solution at 30.°…
no
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a chemistry student weighs out 9.00 g of an unknown solid compound x an…
\(0.0902\ g/mL\)
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a chemistry student is given 5.00 l of a clear aqueous solution at 42.°…
\(32\space g/L\)
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a geochemist in the field takes a small sample of the crystals of miner…
yes, \(24.0\space g/L\)
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in 1993 the minnesota department of health set a health risk limit for …
\(87.0\space\mu g\)
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complete the text with the correct pair of words. could you ______ thes…
take...a part
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complete the table below by writing the symbols for the cation and anio…
| ionic compound | cation | anion | | ---- | ---- | ---- | | \(Cr_3(PO_4)_4\) | \(Cr^{4+}\) | \(PO_4^{3-}\) | | \(VCl_3\) | \(V^{3+}\) | \(Cl^{-}\) | | \(Fe(OH)_3\) | \(Fe^{3+}\) …
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which pair of elements will form an ionic bond? carbon and oxygen nitro…
- For the ionic bond question: barium and chlorine. - For the covalent bond question: carbon and sulfur. - For the \(H_2O\) subscript question: two hydrogen atoms in the compound.
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in a chemical process, the atoms in the reactants are arranged differen…
During photosynthesis, some chemical bonds between atoms in carbon dioxide gas ($CO_2$) and water ($H_2O$) molecules are broken. As atoms are rearranged, new chemical bonds are fo…
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name of element chemical symbol atom, isotope or ion overall electrical…
**First Table (Barium Row):** Name of Element: Barium Overall Electrical Charge: +3 Atomic Number: 56 # of Protons: 56 # of Electrons: 53 **Second Table:** Sulfur - Overall Electr…
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the solubility in water of lonic compound x is measured and found to be…
\( 37.2mL \)
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a certain organic compound o has a solubility in hexane of 66.0 g/l at …
\(4.0\times 10^{2}g\)
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a certain organic compound o has a solubility in hexane of 66.0\\(\\fra…
\(396\ g\)
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the solubility in acetonitrile of molecular compound m is measured and …
\( 0.955L \)
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a chemist prepares a solution of iron(ii) bromide (febr₂) by measuring …
\(5.3\times 10^{-3}\space\frac{mol}{L}\)
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a chemist prepares a solution of potassium chloride (kcl) by measuring …
\(0.013\ \frac{mol}{L}\)
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a chemist prepares a solution of sodium chloride (nacl) by measuring ou…
\(4.48\times 10^{-3}\space mol/L\)
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suppose 6.99 g of magnesium acetate (mg(ch₃co₂)₂) are dissolved in 640.…
| ion | \( \frac{mEq}{L} \) | | ---- | ---- | | \( Mg^{2+} \) | \( 153 \) | | \( CH_3CO_2^{-} \) | \( 153 \) |
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suppose 252 g of potassium phosphate (k₃po₄) are dissolved in 7.70 l of…
| ion | \(\frac{mEq}{L}\) | | ---- | ---- | | \(K^{+}\) | \(462\) | | \(PO_4^{3-}\) | \(462\) |
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suppose 14.7 g of iron(iii) chloride (fecl₃) are dissolved in 480. ml o…
| ion | $\frac{\text{mEq}}{\text{L}}$ | | ---- | ---- | | $\text{Fe}^{3 +}$ | $566$ | | $\text{Cl}^-$ | $566$ |
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a geochemist in the field takes a 17.0 ml sample of water from a rock p…
yes, \(17.0\space g/100\space mL\)
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a geochemist in the field takes a 17.0 ml sample of water from a rock p…
yes, \(17.0\ g\)
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an aqueous solution: has a low ph has water as its solute has a high ph…
has water as its solvent
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is the treatment of cancer. but we must not forget that when radium was…
to illustrate the importance of scientific inquiry for its own sake
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1. define the following terms a. acid a substance that donates hydrogen…
a. An acid is a substance that donates hydrogen ions (\(H^{+}\)). b. A base is a substance that accepts hydrogen ions (\(H^{+}\)). c. \(pH\) is a measure of the acidity or alkalin…
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1. define the following terms a. acid a substance that donates hydrogen…
a. An acid is a substance that donates hydrogen ions (\([H^{+}]\)). b. A base is a substance that accepts hydrogen ions (\([H^{+}]\)). c. pH is a measure of the acidity or alkalin…
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1. define the following terms a. acid b. base c. ph
a. A substance that donates hydrogen ions (\(H^{+}\)) in a solution. b. A substance that donates hydroxide ions (\(OH^{-}\)) (Arrhenius) or accepts hydrogen ions (\(H^{+}\)) (Bron…
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select all that apply an aqueous solution of hydrogen peroxide is used …
The concentration of the peroxide solution is \(0.625\space M\) (first option), \(4.99\times 10^{-3}\space moles\space of\space MnO_4^-\) are reacted (fourth option)
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read the excerpt relating to roger chillingworth from chapter 4 of the …
He has no intention of truly alleviating Hester’s suffering.
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what is the maximum concentration of ag+ that can be added to a 0.00780…
\(3.22\times 10^{-5}M\)
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question 28 (1 point) (lc) the table below shows the main features of t…
B. Establishment of the League of Nations
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which ems wave has a wavelength equal to the size of a molecule and can…
Ultraviolet
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ck12 balancing chem equations possible points: 12.6 do we change the su…
No
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the small dense region consisting of protons and neutrons at the center…
- For "What is a proton?": a stable subatomic particle with a positive electric charge - For "What is an atomic number?": the total number of protons in the nucleus of an atom (No…
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from the text: what is the third step in balancing chemical equations? …
Count the number of atoms of each element that appears as a reactant and as a product. If a polyatomic ion is unchanged on both sides of the equation, count it as a unit.
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which reaction best represents the correct net ionic equation for the r…
\(3Ca^{2 + }(aq)+2PO_4^{3 - }(aq) ightarrow Ca_3(PO_4)_2(s)\) (the last option)
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10 multiple choice 1 point in a salt and water mixture, what happens at…
Water molecules surround and separate salt ions.
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which observation supports the idea that water has stronger cohesion th…
- Question 7: Water forms more drops on a penny before spilling. - Question 8: It allows transport of nutrients and minerals in living organisms. - Question 9: Water stores more e…
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4 multiple choice 1 point why is water considered the universal solvent…
- **Question 4**: Water molecules surround and separate salt ions - **Question 5**: water - **Question 6**: It can store large amounts of heat energy without major temperature cha…
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1 multiple choice 1 point which property of water allows it to form lar…
1. B. Cohesion 2. C. Hydrogen Bonding 3. A. Capillary Action
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4. name these ions a) mg²+ b) s²- c) fe³+ d) br- e) n³-
a) Magnesium ion b) Sulfide ion c) Ferric ion d) Bromide ion e) Nitride ion
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use the precipitation interactive to select the solution that reacts wi…
Precipitate: \(PbCO_3(s)\); Spectator ions: \(K^{+}(aq)\), \(NO_3^{-}(aq)\)
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5 what is the main idea of this text? a some cooks use the chemical rea…
C. Combining vinegar and baking soda leads to an acid - base reaction and a decomposition reaction, two common and important kinds of chemical reactions.
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2 the text describes the sequence of events that happens when acetic ac…
C. An acid - base reaction occurs, forming the salt sodium acetate and carbonic acid.
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1 what is a chemical reaction? a a chemical compound with equal amounts…
D. a process where two or more molecules interact to form one or more different substances
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question 3 of 9 classify each of the observed changes according to whet…
- May be evidence of a chemical reaction: changes in color, bubbles (gas formation), precipitation, explosion or fire. - Not evidence of a chemical reaction: solution colors mixin…
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question 1 of 9 ammonia is a weak base often used in the laboratory exp…
- Inhaling ammonia vapors can cause shortness of breath and even lung damage: True - Concentrated ammonia should be handled in a well - ventilated area, such as a fume hood: True …
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multiple - choice question what is matter? matter is volume. matter is …
Matter is anything that has mass and takes up space.
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the carbon cycle, the active cycling of carbon within and between earth…
movement...biosphere
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22. the family contains all nonmetals and is very reactive. (0.5 points…
Halogens
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21. what is the most reactive group of nonmetals? (0.5 points) * carbon…
Halogens
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20. members of this family all have 2 valence electrons. (0.5 points) *…
Alkaline earth metals