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Question by "chemistry"

172,726 questions

All "Chemistry" Questions

Was Democritus's proposal of the existence of atoms based on scientific methods or ideas? Explain.

Seen 6 months ago Kai Diouf 0 answers

what is "tyranny" and what does Paine compare it to?

Seen 6 months ago Savannah Lopez 0 answers

What weight of a sample of impure oxalic acid should be taken for titration by 0.500 N NaOH so that the percentage of H2C2O4. 2H2O will be twice the buret reading. 

Seen 12 months ago MOA 0 answers

What is the percentage of acetic acid, CH3COOH, in a sample of vinegar if 35.00 mL of 0.468 M NaOH solution is required to neutralize a 25.00 mL sample of the vinegar which has a density of 1.06 g/mL. Acetic acid is monoprotic and has a mm = 60.00 g/mole. 

Seen 12 months ago MOA 0 answers

You will need to prepare about 6 g of the copper ammine product. Estimate how much CuSO4•5H2O you should start with to prepare approximately 6 g of the copper ammine complex.

Seen 12 months ago Poke Man 0 answers

A toy balloon has an internal pressure of \(1.05\) atm and a volume of \(5.0 \mathrm{~L}\). If the temperature where the balloon is released is \(20^{\circ} \mathrm{C}\), what will happen to the volume when the balloon rises to an altitude where the pressure is \(0.65\) atm and the temperature is \(-15^{\circ} \mathrm{C} ?\)

Seen 1 years ago Adams 3 answers

calculate the final temperature when adding 50 ml of water at 60degreese celsius to 25 ml of water at 25 degreese celsius

Seen 1 years ago Margaret 0 answers

Ethane (C2H6) dissociates into methyl rad-
icals at 700 Celcius with a rate constant of
0.00055 s^-1
What is the rate constant at
760 celcius, if the activation energy of the reaction
is 384 kJ/mol?
Answer in units of s^1

Seen 2 years ago Roy Taylor 0 answers

At 20 degrees C ethanol has a density of 0.789 g/ml and H2O has a density of 1.0 g/ml. What is the % by volume of ethanol of a solution made by adding 50g of ethanol with 50g of H2O?Tutor Answer: Use density = mass x volume to convert 50 g ethanol to volume and to convert 50.0 g H2O to volume.
%ethanol v/v = (volume ethanol/total volume?)*100 = ?MY QUESTION:
i thought that density = m/vi've done the math and i think you are right because based on the above formula my answer is 126.74%
However, i don't understand why if the density formula is as you stated?2nd, is this correct? 1/50 = .02, 1/.789 = .01578(0.01578/0.02) x 100 = 78.9%

Seen 2 years ago Amelia Margaret 2 answers

AgNO3+Na3PO4---->AgPO4+Na3NO3

Seen 2 years ago Williams O'Sullivan 0 answers

Seen 2 years ago Jack Connor 1 answers

Calculate the average atomic mass of rubidium if 72.17% of its atoms have a mass of 84.91 amu and 27.83% of its atoms have a mass of 86.91 amu.

Seen 1 years ago Thomas Joe 0 answers

2H2O2 --- 2H2O + O2 is this a redox reaction if so what is the oxidized reactant and reduced reactant

Seen 2 years ago Oscar Rhys 1 answers

Which of the following is defined as the attractive forces between polar molecules?I. dispersion forces;II. dipole-dipole interactions;III. ion-dipole interactions

Seen 2 years ago Isabella 0 answers

Calculate the mass of K4Fe(CN)6 * 3H2O needed to prepare 100.00mL of .0250M solution.

Seen 1 years ago Amelia Margaret 0 answers

Calculate the pH of a solution that is 1.15×10?3M in HCl and 1.10×10?2M in HClO2.

Seen 1 years ago Madison 1 answers

What is the conjugate base of HCO3-?

Write answer as chemical formula

Seen 2 years ago Emily Elizabeth 1 answers

If the solution prepared in the above question is cooled then the temperature will crystals of the compound appear at O degree C !!! am I right?

Seen 1 years ago Gelbero Wilson 0 answers

Ti has __________ in its d orbitals.
A. 1 electron
B. 2 electrons
C. 3 electrons
D. 4 electrons

Seen 2 years ago Charlie Kyle 1 answers

A 2.90 m solution of methanol (CH3OH) in waterhas a density of 0.984 g/mL. What are the (a) mass percent, (b)molarity, and (c) mole percent ofmethanol in this solution?

Seen 1 years ago Adams 2 answers

Calculate the pH of a solution that is 1.15×10−3 M in HCl and 1.10×10−2 M in HClO2.

Seen 1 years ago Harry Callum 1 answers

A student weighs 0.3745 g of unknown and dissolves it in 45 mL of water. A 0.1125 M of HCl is used as a titrant. When the halfpoint (phenolphthaleia color change) ofthe titration is reached, the volume of HCl used is 17.21 mL. What is the estimated % Na2CO3 in the students unknown?

Seen 2 years ago George Reece 0 answers

The compound ICl contains
A) ionic bonds.
B) nonpolar covalent bonds.
C) polar covalent bonds, with partial negative charges on the Cl atoms.
D) polar covalent bonds, with partial negative charges on the I atoms.

Seen 1 years ago Charlie Kyle 0 answers

The pH of a 1.00 x 10 ^-2 M solution of cyanic acid is 2.77 at 25 degree celsius. Calculate Ka for HOCN from this result.

Seen 2 years ago Oscar Rhys 0 answers


At 25°C a solution consists of 0.450 mole of pentane, C5H12, and 0.250 mole of cyclopentane, C5H10. What is the lowering of the vapor pressure of pentane in thissolution? The vapor pressure of the pure liquids at 25°C are 451 torr for pentane and 321 torr for cyclopentane. Assume that the solution is an ideal solution.


115 torr

138 torr

161 torr

187 torr

206 torr

Seen 1 years ago Williams O'Sullivan 4 answers

Can someone help me to do this problem: Perchloroethylene, also known as perc, is the solvent used in most dry cleaning. It consists of C and Cl. Determine theempirical formula of perchloroethylene given that a 2.58-g sample yields 1.37g Co2 in a combustion analysis experiment. Add subscripts to complete the empiricalformula.

Seen 2 years ago Gagnon Martin 1 answers

Potassium permanganate(KMnO4) reacts withoxalic acid (H2C2O4) in aqueous sulfuric acid according to:2KMnO4 + H2C2O4 + 3H2SO4->2MnSO4 + 10 CO2 + * H2O +K2SO4How many milliliters of a .250 M KMnO4 solution are needed toreact completely with 3.225 G of oxalic acid?

Seen 1 years ago sla Bethany 1 answers

What is the limiting reactant in experiment ( converting methyl salicylate to salicylic acid)?
The density of methyl salicylate is 1.18 g/mL at 20 degrees centigrade.
4.0 mL of methyl salicylate used in experiment.
40 mL 6 M NaOH used.
50 mL 8 M H2SO4 used

Final product= 5.32 g salicylic acid

Seen 2 years ago Gagnon Martin 0 answers

1.How many mL (to the nearest mL) of 0.219-M KF solutionshould be added to 680. mL of 0.237-M HF to prepare a pH = 3.40solution? mL KF
2.What volume (to the nearest 0.1 mL) of 6.10-M HCl must beadded to 0.500 L of 0.150-M K2HPO4 to preparea pH = 7.60 buffer?
mL

Seen 1 years ago Madison 1 answers

Problem looks like this:

The following questions refer to Al + O2

a. If you start with 45g of Al and 60g of O2,How much product do you make?
bIs it an ionic or covalent compound?
c.Name the product
d. Predict if the product is liquid, gas or solid.


Thanks!

Seen 2 years ago Madison 0 answers

semicarbazide→weak acidGive the major product of the following reaction (after aqueous workup). If no reaction occurs, draw the starting material. Semicarbazide = H2NCONHNH2. Thanks.

Seen 2 years ago George Reece 1 answers

What is the vant hoff factor of barium hydroxide, calcium chloride, potassium hydrogen phthalate, sodium hydroxide, and potassium hydroxide

Seen 1 years ago sla Bethany 0 answers

Part A Arrange the following oxoacids in order of decreasing acid strength.
Rank from strongest to weakest acid. To rank items as equivalent, overlap them.
1. HClO2
2. HClO3
3. HBrO
4. HClO

FYI-It is not HClO3 > HClO2 > HBrO> HClO
Thanks

Seen 1 years ago George Reece 1 answers

concentration of Ca(OH)2 0.339 M
volume vinegar solution 11.84 mL
mass vinegar solution 11.90 g
volume of Ca(OH)2 solution 12.05 mL


mmol of Ca(OH)2
mmol of HC2H3O2
mass of HC2H3O2:
mass % of HC2H3O2 in the original sample:
molarity of HC2H3O2 in the original sample:

Seen 2 years ago Brown Walsh 0 answers

Alkenes can be converted to alcohols by reaction with mercuric acetate to form a ?-hydroxyalkylmercury(II) acetate compound, a reaction called oxymercuration. Subsequent reduction with NaBH4 reduces the C?Hg bond to a C?H bond, forming the alkyl alcohol, a reaction called demercuration. Draw the structures of the Hg-containing compound(s) and the final alcohol product(s) formed in the following reaction sequence, omitting, by products. If applicable, draw hydrogen at a chirality center and indicate stereochemistry via wedge-and-dash bonds.


Neutral produst (s) of oxymercuration. Include stereoisomers, if any

image from custom entry tool HG(OOCCH3)2

----------------->

H2O,THF





Alcohol product (s) of demercuration. Include stereoisomers, if any



NaBH4

------->

HO-







Select all that apply: The alcohol product(s) of the reaction is characterized as being


_____ R,R

_____ R,S (and/or S,R)

_____ S,S

_____ achiral

_____ racemic

_____ diastereomers

_____ R

_____ S

Seen 2 years ago Wilson Anderson 3 answers

the atomic number of oxygen is 8, because oxygen has

Seen 1 years ago Harvey obrien 0 answers

Applying Hess’s Law, from the enthalpies of reactions,
NO (g) + O3 (g) ? NO2(g) + O2(g) ?H = -198.9 kJ
O3(g) ? 3/2 O2 (g) ?H = -142.3 kJ
O2(g) ? 2 O(g) ?H = +495.0 kJ

Calculate the standard enthalpy change (?H) for the reaction
NO(g) + O (g) ? NO2 (g)

(please show work)

Seen 1 years ago Madison 0 answers

What happens to these physical properties as the strength of intermolecular forces increases?My answers are there as well but its not correctIncrease or decrease?
a) melting point - increases
b) vapor pressure-increases
c) boiling point- increases
d) viscosity - decreases
e) surface tension - decreases

Seen 1 years ago Adams 1 answers

pleas help me balance this redox reaction in Bi2O3 +NaOH +NaOCl= NaBiO3 +NaCl

Seen 2 years ago Williams O'Sullivan 0 answers

An energy of 1.09x10^3 KJ/mol is required to convert gaseous carbon atoms to gaseous C+ ions and electrons. What is the maximum wavelength, in nm, of electromagneticradiation with sufficient energy to cause ionization energy to a single carbon atom? In what region of the electromagnetic spectrum is this photon found?

Seen 1 years ago Williams O'Sullivan 0 answers

In one process,8.00X10^3 kg of FeTiO3 yielded 3.67x10^3 kg of TiO2 what is the percent yield of the reaction.?

Seen 1 years ago Sophia Jennifer 1 answers

Write the total ionic equation (also known as the complete ionic equation) for the reaction of potassium carbonate with hydrochloric acid. Indicate the physical statesusing the abbreviation (s) solid, (l) liquid, (g) gas and (aq) for aqueous solution.

Seen 1 years ago Emily Elizabeth 0 answers

how many repeating units are found in a monomer. a dimer, a trimer, and a polymer?

Seen 2 years ago Amelia Margaret 5 answers

A solution is made by mixing exactly 500 mL of 0.167 M NaOH with exactly 500 mL 0.100 M CH3COOH. Calculate the equilibrium concentrations of H+, CH3COOH, CH3COO-, OH-,and Na+.

Seen 2 years ago Oscar Rhys 0 answers

which reaction of these potential acids and bases does not occur to any appreciable degree due to an unfavorable equilibrium?
a-NaNH2 + CH3CH2CH2CH2CH2CH3
b-CH3CH2CO2Na + HI
c-CH3Li in hexane + ethyne
d-NaH + methanol
e-Two of the above will not occur

Seen 2 years ago Li Smith 0 answers

A wooden door lintel from an excavated site in Mexico would be expected to have what ratio of carbon-14 to carbon-12 atoms if the lintel is 6.8 x 103 y old?
C-14 atoms : C-12 atoms = __________?

Seen 1 years ago Garcia 1 answers

For the following processes that show the formation of ions, use the periodic table to indicate the number of electrons and protons present in both the ion and theneutral atom from which the ion is made.

(a) Ca----> Ca2+ + 2e-
electrons in ion:___________________
protons in ion:_____________________
electrons in neutral atom:_____________________
protons in neutral atom:_______________________

(b) Sn-----> Sn4+ + 4e-
electrons in ion:___________________
protons in ion:_____________________
electrons in neutral atom:_____________________
protons in neutral atom:_______________________

(c) Fe----> Fe3+ + 3e-
electrons in ion:___________________
protons in ion:_____________________
electrons in neutral atom:_____________________
protons in neutral atom:_______________________

(d) Br + e- -------> Br -
electrons in ion:___________________
protons in ion:_____________________
electrons in neutral atom:_____________________
protons in neutral atom:_______________________

(e) Rb-------> Rb+ + e-
electrons in ion:___________________
protons in ion:_____________________
electrons in neutral atom:_____________________
protons in neutral atom:_______________________

(f) P + 3e- -------> P3-
electrons in ion:___________________
protons in ion:_____________________
electrons in neutral atom:_____________________
protons in neutral atom:_______________________

Seen 2 years ago Harry Callum 0 answers

All the following are oxidation-reduction reactions except:

A) H2(g) + F2 ? 2HF(g)
B) Ca(s) + H2(g) ? CaH2(s)
C) 2K(s) + 2H2O(l) ? 2KOH(aq) + H2(g)
D) 6Li(s) + N2(g) ? 2Li3N(s)
E) Mg3N2(s)+ 6H2O(l) ? 3Mg(OH)2(s) + 2NH3(g)

Seen 1 years ago James Charlie 0 answers

The molecular formula mass of this compound is 120 amu. What are the subscripts in the actual molecular formula?

Enter the subscripts for C , H, and O, respectively, separated by commas (e.g., 5,6,7).

Seen 1 years ago Williams O'Sullivan 0 answers

Write net Bronsted equations and determine the equilibrium constants for the acid-base reactions that occur when aqueous solutions of the following are mixed.
Instructions:
Enter all substances in the order listed at the top of the column.
Use a carot to indicate a superscript, but do nothing for subscripts.
Use a hyphen + greater than (->) for yields.
Click on the eye symbol to check your formatting.
Report K to three sig figs even though it is good to only two.
Group 1A and 7A ions (except fluoride) are spectator ions.


Reactants Rxn: Acid(1) + Base(2) = Base(1) + Acid(2) K (three sig figs)

acetic acid + ammonia



perchloric acid + sodium cyanide




formic acid (HCHO2) + sodium nitrite





Na2HPO4 + KClO





H2SO3 + K2SO4


Seen 2 years ago William Damian 1 answers

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