Chemistry

Chemistry
Can anyone help me check my classifications of these into metallic, ionic, molecular or covalent network, and if I am wrong tell me why Aluminum - Mettalic Ascorbic acid - ionic Graphite - covalent Paraffin - molecular Palmitic acid - ionic Sodium chloride - covalent Sucrose...

Chemistry - Equilibrium
Can anyone find out if I did it right or not? Thanks A 0.682?g sample of ICl(g) is placed in a 625?mL reaction vessel at 682 K. When equilibrium is reached between the ICl(g) and I2(g) and Cl2(g) formed by its dissociation, 0.0383 g I2(g)is present. What is Kc for this ...

Analytical chemistry
a solution of 0.010M K2Cr2O7 with a volume of 60.00ml reacts in a titration reaction with 20.00ml of FeSO4 in sulphuric acid. Calculate the normality of FeSO4.

Chemistry
Which of these most accurately describes the motion of gas particles? 1.) particles making up gases are mostly fixed in their locations and have vibrational motion. 2.) particles making up gases have few intermolecular interactions and are free to move. 3.) particles making ...

Chemistry
Molecular crystals consist of molecules held together by intermolecular forces. Ice is a good example. In ice, water molecules are held together by ______, and by London dispersion forces. Intermolecular forces are _______ than ionic or covalent bonds. Hence, molecular ...

Chemistry
A 3.00- L flask is filled with gaseous ammonia, N H 3 . The gas pressure measured at 28.0 ∘ C is 2.05 atm . Assuming ideal gas behavior, how many grams of ammonia are in the flask?

Chemistry
IF 24.5 mL of the .10M NaOH solutino is required to reach the endpoint in a titration with an unknown monoprotic acid, how many moles of the acid were present?

Ap Chemistry
Calculate the pH at the equivalence point in titrating 0.100 M solutions of each of the following with 0.038 M NaOH. (a) hydrobromic acid (HBr) (b) lactic acid (HC3H5O3) (c) sodium hydrogen chromate (NaHCrO4)

Chemistry
Which is true about the effusion rates of helium and sulphur dioxide when the molar mass of helium is 4 grams/mole and the molar mass of sulphur dioxide is 64 grams? A- Sulphur dioxide effuses 4 times faster than helium. B- Sulphur dioxide effuses 0.25 times faster than helium...

Chemistry
Which is a chemical property of hydrogen? A. It is a light gas. B. It is a combustible gas. C. It is a colorless gas. D. It has a boiling point of -252.87°C. E. It is a good conductor of electricity.

Chemistry
At what temperature (ºC)  will 0.460 mol of carbon dioxide, at a pressure of 276 kPa occupy a volume of 2574 mL?

Chemistry
When 1.578 grams of a hydrocarbon, CxHy, were burned in a combustion analysis apparatus, 4.951 grams of CO2 and 2.027 grams of H2O were produced. In a separate experiment, the molar mass of the compound was found to be 56.11 g/mol. Determine the empirical formula and the ...

Chemistry
Determine the molar concentration of ethanol (C2H6O) in a wine that is 14% ethanol by mass. The density of this wine is 0.93 g/cm^3.

Chemistry
Determine the molar concentration of ethanol (C2H6O) in a wine that is 14% ethanol by mass. The density of this wine is 0.93 g/cm^3.

Chemistry - Chemical Equilibrium
A sample of NH4HS(s) is placed in a 2.61 −L flask containing 0.120 mol NH3(g). NH4HS(s)⇌NH3(g)+H2S(g) KP=0.108 at 25∘C What will be the total gas pressure when equilibrium is established at 25∘C? Express your answer using four significant figures. I've done PV=nRT P= ...

Chemistry
hydrobromic acid (50.5) calculate the concentration in mol/L. (MW HBr: 80.91 g/mol, density: 1.49 g/mL)

chemistry
calculate the ph of half cell Pt,H2|H2SO4, if its electrode potential is 0.03V

Chemistry
If an aqueous solution is 5.08 % by weight in sodium chloride and contains 1.79 g of sodium chloride, what mass of water is present in the solution?

6thMath
You walked 2⁄15 miles from your chemistry class to your economics class at a constant speed of 0.8 miles per hour. How long did this take you?

Chemistry
The temperature of a lead fishing weight rises from 26 C to 38 C as it absorbs 11.3 J of heat. What is the mass of the fishing weight in grams? ( The specific heat capacity of lead is 0.128 J /g C )

Chemistry
Consider the reaction below : P4(s) + 5O2(g) P4O10(s) How many grams of phosphorus react with 1.195 x 102 L of oxygen (O2) at STP (standard temperature and pressure) to form tetraphosphorus decaoxide?

Chemistry
How do I plot the freundlich isotherm graph given P/atm and V/cm3 data. I know that the plot is suppose to be log x/M vs log c. However, how do I get the x/m from the data and which is the c. I have already plotted the Langmuir isotherm of this data. How do I manipulate the ...

Chemistry
A sample of oxygen has a volume of 205cm³ when its temperature is 22.0°C and its pressure is 30.8 kPa. What volume will the gas occupy at STP?

Chemistry
The molecules present in 5.2gms of glucose will be c6h12o6

Chemistry
One liter of a buffer composed of 1.2 M HNO2 and 0.8 M NaNO2 is mixed with 400 mL of 0.5 M NaOH. What is the new pH? Assume the pKa of HNO2 is 3.4.

Chemistry
How many moles of carbon dioxide would be produced if 0.28 moles of propane, C3H8, were combusted? C3H8 + 5 O2 --> 3 CO2 + 4 H20

chemistry
A mixture of 1-butanol and chlorobenzene is heated and the vapours at 115.3 degrees celsius condensed and collected. What is the percent weight composition of this distillate if a careful fractional distillation was performed?

chemistry
i need the exat percentage of nitrogen in magnesium nitride

Chemistry
what is ethanol’s polarity? None, polar, partial or both polar and nonpolar. Would it be both polar and nonpolar

Chemistry
How many moles of H2SO4 are present in 250 g of an aqueous solution that is 4.8 m (molal)? The density of the solution is1.58 g/mL.

Chemistry
A graduated cylinder has a mass of 80.4 g when empty. When 20.0 mL of water is added, the graduated cylinder has a mass of 100.4 g. If a stone is added to the graduated cylinder, the water level rises to 43.5 mL and the total mass is now 156.1 g. What is the density of the stone?

Chemistry
Thanks in advance. A student prepared a solution of NaCl by dissolving 55.0 grams of sodium chloride in 570 mL of water. What is the percent by mass of the NaCl solution?

Chemistry
A certain mass(m) of an impure iron sample of 40% purity ,is treated with an excess of HCl to give H2 that occupies 44.8 L at s.t.p ( Vm=22.4) where the yeild of the reaction is 0.8. A) calculate m. B) deduce the mass of HCl reacted. Thanks in advance!!

chemistry
Commercial aqueous hydrogen peroxide was diluted 150 times. 25cm3 of the sample solution was titrated with 0.02molar KMnO4 and 26.3cm3 was required to reach the end point. Calculate the molar concentration of hydrogen peroxide

chemistry
champagne is usually cooled in a refrigerator prior to opening. Its also opened very carefully. what would happen if a warm bottle of champagne is shaken and opened quickly and forcefully?

Chemistry
A certain mass(m) of an impure iron sample of 40% purity ,is treated with an excess of HCl to give H2 that occupies 44.8 L at s.t.p ( Vm=22.4) where the yeild of the reaction is 0.8. A) calculate m. B) deduce the mass of HCl reacted. Thanks in advance!!

chemistry
How can variation in hardness of water be determined in a laboratory? How is the using of sodium carbonate disadvantageous?

AP Chemistry
I am honestly lost on this question and you can't proceed without solving the first on, so if anyone would be so inclines to help me out Aluminum metal reacts with zinc(II) ion in an aqueous solution by the following half-cell reactions: Al(s) → Al3+(aq) + 3e− Zn2+(aq) + ...

Chemistry Hess’s Law
This is not going to be formatted we’ll because there is no subscript here. H2 + 1/2 O2 —> H2O -286kJ N2O5 + H2O —> 2HNO3 -77kJ 1/2N2 + 3/2 O2 + 1/2 H2 —> HNO3 -174kJ Calculate the *Delta* H for 2N2 + 5O2 —-> 2N2O5 I attempted this problem and got +20kJ. ...

Chemistry
In this experiment 4.0g of ferrous ammonium sulfate is used. Assuming everything else is added in excess; calculate the theoretical yield of the iron complex. Work through the entire reaction sequence; do not simply assume the number of moles of limiting reaction equals the ...

General chemistry
1) How high above the inner blue cone of the burner flame should the crucible be when the Mg is heated? 2) What should you do if you see white smoke rising from the crucible in the early stages of heating the Mg? 3) How will you know when the reaction between Mg and O2 is ...

General Chemistry
The formula of a compound of lead (Pb) and sulfur (S) was determined using the method in this module. A sample of Pb was weighed into a crucible and covered with finely powdered S. The crucible was covered and heated to allow the Pb and S to react. Additional heating burned ...

General chemistry
Briefly explain if wearing googles or other eye protection remove the hazard for these students.

General chemistry
Ammonia fumes can permanently fog soft contact lenses. Briefly explain why students wearing soft contact lenses should be particularly careful when doing this experiment.

chemistry
why is polystyrene cup use rather than a glass beaker to conduct exothermic or endothermic reaction?

Chemistry
Lead(II) chromate (PbCrO4) is used as a yellow pigment to designate traffic lanes, but has been banned from house paint because of the potential for lead poisoning. The compound is produced from chromite (FeCr2O4), an ore of chromium: FeCr2O4 + K2CO3 + O2 -> Fe2O3 + K2CrO4...

Chemistry
What volume of concentrated sulfuric acid (20% weight/weight, density = 1.14) is needed to prepare 1 L of a 0.5 N solution of sulfuric acid?

chemistry
If delta G (Gibbs) is positive and you are trying to find at what temperature the reaction is spontaneous would the formula be: T< H/S ? G=H-TS H-TS>0 T< H/S then the temperature found would be the temp at which the reaction is spontaneous?

Chemistry
How many grams of Na2SO3 (Sodium Sulfite) must be added to 225 mL of 0.0777 M sulfurous acid (H2SO3) to prepare a buffer at pH = 7.4000? H2SO3 has a pKa1 = 1.857 and pKa2 = 7.172.

AP Chemistry
Determine a pH range for which a buffer system containing benzoic acid would be appropriate. Devise a recipe for preparing 1.0 L of buffer solution that contains a total of 0.150 mol of buffer components (acid plus conjugate base) and has a pH of 4.48. The conjugate base will ...

chemistry (need help)
From the standpoint of solutions what processes lead to rainfall or other forms of atmospheric precipitation? I don't know because I understand they water cycle but this doesn't really have much to do with from the standpoint of solutions.

AP Chemistry
How many g of C2H5NH3Cl will be needed to combine with 4.7 g of C2H5NH2 to produce 0.250 L of buffer solution at a pH of 10.00? I can do this problem with mL and M but not w/out

Chemistry
The thermal decomposition of 1.6608 g of MgSO4 * H2O produces 1.4446 g of a product in a well-behaved reaction. There are two possibilities: 1) MgSO4 * H2O(s) -> MgSO4(s) + H2O(g) 2) MgSO4 * H2O(s) -> MgO(s) + SO3(g) + H2O(g) Complete the following table, and then ...

Chemistry
You have a 35.5 g of a saturated solution of potassium nitrate at 80oC which you cool to 40oC, what mass of potassium nitrate will precipitate out of solution? @80 degrees C solubility is 160g solute/100g H2O @40 degrees C solubility is 60g solute/100g H2O

Chemistry
Which of the following pairs of compounds can be used to illustrate the law of multiple proportion? a) NH3 and NH4Cl b) ZnO2 and ZnCl2 c) H2O and HCl d) NO and NO2 Could you also briefly explain why, please. Thank you.

Chemistry
The 1-D harmonic oscillator is a good approximation for the vibration of the bond between the atoms of a diatomic molecule. Using this treatment, predict the wavenumber in cm-1 required to vibrationally excite the HCl molecule, given that the force constant for the H-Cl bond ...

Chemistry
The delocalized electrons in a long-chain polyene exist in quantum states that can be reasonably approximated by the particle in a one-dimensional box model. The length L of the box is the end-to-end distance. Suppose one such polymer has a length L = 4.00 nm. How much energy ...

chemistry
2NO2(g) <-----> N2O4(g) If 0.625mol of dinitrogen tetraoxide in 5.0L is allowed to come to equilibrium and at equilibrium has a concentration of 0.0750M, Calculate K for this reaction. Does K= 7.5?

Chemistry
How many grams of nitrogen would be contained in .025 moles of HNO3?

Chemistry
What is the numerical relationship between the volume of base added to reach the first endpoint and the volume added to reach the final endpoint in the titration of a diprotic acid? What is the relationship for a triprotic acid?

Chemistry/Science
What is the proper way to dilute 6M HCl to 1 M HCl?

Chemistry
Is an ammonium an acid or s base? Is it strong or weak? Is it a weak, acid?

Chemistry
An ancient artifact is found to have a ratio of C-14 to C-12 that is 1/8th the ratio of C-14 to C-12 found in objects today. How old is the artifact of the half like of C-14 is 5715 years?

chemistry
A sample of argon initially has a volume of 5.0 L and the pressure is 2 atm. If the final temperature is 30° C, the final volume is 6 L, and the final pressure is 8atm, what was the initial temperature of the argon?

chemistry
Rain: From the standpoint of solutions what processes lead to rain fall or other forms of atmospheric precipitation?

Chemistry
Given the same reaction as before: 4 KO2 + 2 H2O + 4 CO2 ==> 4 KHCO3 + 3 O2 Great! 3.21 moles of O2 were produced. Now, How many molecules of O2 does this number of moles represent?

Chemistry
Now if your lab partner determined that there were 3.824 x 1023 atoms of H in an unknown sample of C2H4Cl2, how many milligrams would the unknown sample weigh?

Chemistry
Now if your lab partner determined that there were 1.157 x 1020 atoms of Mn in an unknown sample of KMnO4, how many milligrams would the unknown sample weigh?

Organic Chemistry
what would be the disadvantage of recrystallizing salicylic acid after is has already been recrystallized?

Chemistry
At 25oC, the equilibrium pressure of ammonia vapour above a 0.500 M aqueous ammonia solution is 0.84 kPa. Calculate the Henry's law constant for ammonia in M/bar. Do not include units. Include 4 significant figures.

chemistry
Which one of the following pairs has only London dispersion forces as the intermolecular force between them? 1.) H2O; HF 2.)He; He 3.) HCl; HCl 4.) Ne; HCl please help I am so lost

chemistry
What is the difference between dipole-dipole interactions and dipole-induced dipole interactions? 1.) dipole-dipole interactions involve two non polar molecules. Dipole induced dipole interactions involve one polar molecule with a permanent dipole and one non-polar molecule. 2...

Chemistry
Calculate the pressure in atmospheres in the ocean at a depth of 3.20 km assuming the constant density of sea water in the water column is 1.10 g/mL. The atmospheric pressure is 1.00 atm.

Chemistry
What is the energy in Joules of a photon of light having a frequency of 1.000 1018 typical of the gamma ray region of the electromagnetic spectrum?

Chemistry
Write down the electron configuration of sodium in the format 1s2_2s2_2p6_etc_etc.

Chemistry
Write down the electron configuration of the Cu(I) ion in the format 1s2_2s2_2p6_etc_etc.

Chemistry
Of the 3 elements nitrogen , oxygen , and aluminum, what is the atomic number of the one that has the smallest atomic radius?

Chemistry
Of the 3 elements fluorine, nitrogen, and carbon, what is the atomic number of the one that has the largest atomic radius?

Chemistry
Of the 3 elements fluorine, nitrogen, and carbon , what is the atomic number of the one that has the lowest ionization energy?

Chemistry
Of the 3 elements nitrogen, oxygen, and fluorine, what is the atomic number of the one that has the highest ionization energy?

Chemistry
What is the l quantum number for the last electron added in the Aufbau procedure for forming the electron configuration of barium?

Chemistry
What is the n quantum number for the last electron added in the Aufbau procedure for forming the electron configuration of uranium?

Chemistry
How can I determine the H3O+ concentration of 0.50 M HCHO2 if I don't have the Ph of the solution?

AP Chemistry
If 25 mL of a 0.5 M NaOH solution were needed to reach the equivalence point of a 20 mL HCl solution, what was the initial analyte concentration? I am confused how to solve this problem, and also, what does "initial analyte concentration" refer to? Thanks!

chemistry
what behavior do all salts exhibit, when dissolved in water? They dissolve in water , although there are some exceptions..... Indicators: Are indicators consumed in reactions. Example. Yes they are consumed because when Phenophalien is added it changes the color of certain ...

Chemistry
How is a strong base similar to a weak base? What is observed when an acid dissociates in water?

Chemistry
The work function for a certain metal is 3.00 eV. Calculate the speed of the electrons in m/s ejected by light of wavelength 209 nm. If it is not ejected, report a speed of 0.0.

Chemistry
Calculate the wavelength in nm of the line with n = 6 in the Pfund series of the spectrum of atomic hydrogen.

Chemistry
Calculate the speed of electrons in meters per second if their characteristic wavelength is 543 pm.

chemistry
Water: describe how its molecular structure is responsible for its ability to serve as a solvent for salts and other ionic or polar materials. Explain how you can be sure it isn't a straight molecule? Is it because hydrogens can come off a attach to other things? I don't know ...

Chemistry
Calculate the change in enthalpy produced by dissolving 14.3 g of NaOH in 65.0 g of water if the temperature increases 49.1°C and the specific heat of water is 4.18 J/g°C Do I have to use the 14.3g of NaOH?

Chemistry
Several compounds containing only sulfur (S) and fluorine (F) are known. Three of them have the following compositions: i. 1.188 g of F for every 1.000 g of S ii. 2.375 g of F for every 1.000 g of S iii. 3.563 g of F for every 1.000 g of S How do these data illustrate the law ...

Chemistry
Write the formula for each of the following compounds: a. cesium bromide b. barium sulfate c. ammonium chloride d. chlorine monoxide e. silicon tetrachloride f. chlorine trifluoride g. beryllium oxide h. magnesium fluoride

Chemistry
Name each of the following compounds: a. CrO3 c. Al2O3 e. CaBr2 b. Cr2O3 d. NaH f. ZnCl2

chemistry
using the kinetic theory what happens to the particles in oxygen as it cools down

chemistry
water: describe how its molecular structure is responsible for its ability to serve as a solvent for salts and other ionic or polar materials. Explain how you can be sure it isn't a straight molecule? Is it because hydrogens can come off a attach to other things? I don't know ...

Chemistry
A compound is found to contain 63.52 % iron and 36.48 % sulfur. Find its empirical formula. FeS FeS2 Fe2S Fe2s3

Chemistry
If a chemist titrates 300.0 mL of H2SO4 with a 3.0 M solution of NaOH and requires only 3.4 mL of the base to reach the endpoint, what is the concentration of the sulfuric acid?

Chemistry
The mass of a dry, 50 mL beaker is 49.135 g. The observed volume of water in a volumetric pipet is 20.00 mL. This water is transferred to the beaker and the combined mass of the water and the beaker is found to be 69.122 g. Given that the density of water at 24 degrees Celsius...

math
In Purdue's Chemistry department, the chemists have found that in a water based solution containing 24 grams of certain undissolved chemicals, the rate of change of the amount of chemicals dissolved in the solution is proportional to the amount of the undissolved chemicals. ...

  1. Pages:
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. Next>>

Homework Help: Science