Post a New Question

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
How many liters would 1.000g of helium gas occupy at STP?

chemistry
Calculate ∆S universe for the process H2O (s) → H2O (l) given that ∆Hfusion = 6.02 kJ/mol and ∆S system = 22.1 J/K mol . Remember that ∆S surrounding = -∆Hsystem / T. a) -20oC b) 0oC c) 20oC

Chemistry 112
Can rate of law be a decimal??

organic chemistry
The constants for Antoine’s equation for TCE (based on log10 and o C) are: A= 6.5183, B = 1018.6 and C = 192.7. If a container (negligible volume) is placed in a sealed room 1000 m3 at 30 oC, how many grams of TCE will evaporate upon reaching equilibrium with the liquid and ...

chemistry
From each pair of substances below, choose the one with the higher molar So, at 298 K a) Hg (s), Hg (l) d) C2H6 (g), C2H4 (g) b) HI (g), HCl (g) e) H2 (1 atm), H2 (2 atm), 1 mol at 298 K c) NH3 (g), Ne (g) f) NaCl(s), NaCl (aq)

Chemistry
Compunds formed by NH4+ and NO3-

Chemistry
The vapor pressure of pure water at 30C is 31.8Torr. What is the vapor pressure of a solution of NaCl dissolved in water when the mole fraction of NaCl is 0.111? I am wondering if this would be correct. 0.11*31.8= 3.5 Torr Is there another way to solve this and get the same ...

chemistry
a pipet can be calibrated. we expected the volume to be 25.00ml, but the actual volume was significantly less. if you had measured the density of an unknown with this pipet and assumed that v=25.00ml, your result would not be correct. would it be too high or too low? Explain

Chemistry
Given Ka values of 5.76×10^-10 & 4.8×10^-10, for NH4+ anf HCN.what is the equilibrium constant for following reaction? NH4+ + CN- >< NH3 + HCN

chemistry
What is the half-life of an isotope that decays to 50% of its original activity in 55.6 hours?

Chemistry
Say there is a diluted solution and we need to find the final concentration of it, using the equation M1V1 = M2V2. Does this method change, if the compound (concentration that we're trying to find), is in a solution that has already reacted with another compound? Ex: CaCO3 + ...

Chemistry
In the aqueous solution of H2SO4 its mole fraction is 0.2 then closest value of molality or solution is a)13.9 b)9.8 c)10.2 d)11.2

Chemistry
What is the pH of a buffer solution of 0.125M Acetic acid and 0.250M Sodium acetate? the Pk of Acetic acid is 4.76

Chemistry
What substance will have the lowest surface tension? A) HOCH2CH2OH B) CH2F2 C) CH3CH2F D) CH3CH2OH E) CH3CH2CH CH3CH3

College Chemistry
If the reaction rate increases by 2.6 when the temperature increases from 20-30 degrees Celsius, what is Ea? Do we use 2.6 in place of (k2/k1) or multiply something by 2.6? Lost, please help.

chemistry
what mass in grams of hydrogen gas is produced using234g of nitric acid

Chemistry
How much energy is required to convert 360 gram of ice having temp -10 c to convert in to steam

Chemistry
The density of water at 60 degrees C is 0.98338 g/mL. What is the mass of 37.48 mL of water in a graduated cylinder (not including the mass of the graduated cylinder)

Chemistry
(Paper Chromatography) 1. What carrier solution might work well to separate newspaper inks? Why? 2. What carrier solution might work to separate different salts? Why? 3. What carrier solution might work to separate different fatty acids? Why? I really have no idea what the ...

Chemistry
1. An empty balloon weighs 10.0 g and is filled to a volume of 20.0 L with CO gas. If the density of air at 25.0 °C and 1.00 atm is 1.17 g/L, will the balloon float? 2. Determine the volume of gas produced at 20.0 °C and 1.00 atm from the complete combustion of 1.0 kg of ...

Chemistry
A container of gas at 53 psi is compressed to one third its original volume. What is the new pressure of the gas?

Chemistry II
How much heat (in kJ) is required to warm 10.0 g of ice, initially at -15.0 ∘C, to steam at 114.0 ∘C? The heat capacity of ice is 2.09 J/g⋅∘C and that of steam is 2.01 J/g⋅∘C.

Chemistry
How much heat (in kJ) is required to warm 10.0 g of ice, initially at -15.0 ∘C, to steam at 114.0 ∘C? The heat capacity of ice is 2.09 J/g⋅∘C and that of steam is 2.01 J/g⋅∘C.

Chemistry
Calculate the number of moles of 2.8 of nitrogen (iv) oxide.

Chemistry
This is a conversion question. 2.78mg to ___________ kg. I've tried the standard formula - ex (2.5 m) (1000m/1m)=2500mm - but it just gives me 2.78e-6. Please help it's driving me crazy.

Chemistry
Compound K is a hydrocarbon. Combustion of 6.51 g of K gave 20.47 g of carbon dioxide and 8.36 g of water. The relative molecular mass of K was found to be 84. Calculate the empirical and molecular formula of K

Chemistry
Assuming I have the following reaction: LiO2 + C +2 Mg -> LiC + 2MgO I'll be using 0.1 g of LiO2 to react with 1.2 mol C and 2.2 mol Mg in excess. How much C and Mg in grams do I need?

chemistry
Express the composition of each of the following compounds as the mass percents of its elements...? 59) Express the composition of each of the following compounds as the mass percents of its elements. a) formaldehyde, CH2O b) glucose, C6H12O6 c) acetic acid, HC2H3O2

Chemistry
In a discussion,a study argued that calcium ions when asded to toothpaste would enhance the performance of the toothpaste by further strengthening teeth. Therefore, he suggested the addition of calcium hydrogen carbonate, calculate the solubility of calcium fluoride in a ...

chemistry
1 g of a mixture of nahco3 annd na2co3 was heated at 300 deg celsius.the volume of co2 obtained at stp are found to be 112ml.calculate the % of na2co3 in the mixture. please help i am not able to understand!!

Chemistry
How much energy (in kilojoules) is released when 29.0 g of ethanol vapor at 88.0 ∘C is cooled to -10.0 ∘C? Express your answer to two significant figures. q = ______________ kJ Ethanol has mp = -114.5 ∘C, bp = 78.4 ∘C, ΔHvap = 38.56 kJ/mol and ΔHfusion = 4.60 kJ/mol...

Chemistry
Explain why olive oil has a higher viscosity than water, by selecting an appropriate word from the provided list and filling in the following blanks. Oleic acid has a higher viscosity than water because it is a much________ molecule than water with ________ ________. List of ...

Chemistry
Rxn 1:     4 NH3(g) + 5 O2(g) ⇌ 4 NO(g) + 6 H2O(g)         If the equilibrium constant, Kc, for Rxn 1 is 0.0015, determine the equilibrium constant, Kc, for the    reaction:   2 NH3(g) + 5/2 O2(g) ⇌ 2 NO(g) + 3 H2O(g) I'm not sure how to start this problem ...

Chemistry
How much does 1.0 ft^3 of mercury weigh given the density of mercury is 13.6 g/ml?

chemistry
an over the counter pain reliever melts at 78degree celcius. convert this temperature to f and k

chemistry
how many fluid ounces are contained in 1qt of milk. 2.how many cups are contained in 1l of soda

chemistry
why should a new boiling Chip be added to a liquid that has already been heated with a boiling Chip

chemistry
1) A Galvanic cell runs on the following reaction: Co (s) + Cu2+ (aq) → Co2+ (aq) + Cu (s) Draw a diagram for this Galvanic cell, labeling the electron flow, the anode and cathode, and the positive and negative sides of the Galvanic cell. 2) A Galvanic cell runs on the ...

chemistry
a woman was told to take a dose of 1.20g of calcium daily ,how many 200mg tablets should she take^

Chemistry 112
Calculate the MnO4- concentration of the diluted sample when the sample is prepared in the following manner: Add 2 drops oxalic acid, 4 drops permanganate and 8 drops water. The original permanganate is 0.25M. I don't understand how to do this, any help would be appreciated.

Some basic concept of chemistry
0.5M aluminum sulphate aques solution normality calculation

Chemistry
How many kcal are needed to raise the temperature of 120 g of water from 15°C to 75°C?

Chemistry
For each of the following precipitation reactions calculate how many grams of the first reactant are necessary to completely react with 55.8 g of the second reactant. K2SO4 + Sr(NO3)2 + SrSO4 + 2KNO3

CHEMISTRY
The enthalpy of cimbustion for Octane vapor, C8H18, a component of gasoline, is -5512.0kJ/mol. a. Write the equation for the combustion of Octane, including the energy term. b. Calculate the energy change when 45g of Octane burn. c. Calculate the energy produced when 45g of ...

Chemistry
What intermolecular forces are responsible for neoprene's stretchiness?

Chemistry
How much energy, in calories, does it take to convert 20.0 grams of solid water, at 0.0 degrees C, into liquid water, at 0.0 degrees C? (The enthalpy of fusion for H2O is 1.44 kcal/mol)

Chemistry
How many grams of AlCl3 are produced when 53.0 g of Al reacts?

chemistry
Ethanol has an enthalpy of evaporation of 38.6kJ/mol, and a normal boiling point of 78.4oC. What is the vapor pressure of ethanol at 15oC? Hint: the normal boiling point is when the vapor pressure reaches 1 atm. Use, . Pay attention to use right units

chemistry
2. 50.0 mL of 1 M NaOH(aq) and 50.0 mL of 1 M HNO3(aq), both initially at 18.6°C, were mixed in a Styrofoam cup calorimeter. The temperature of the solution rose to 25.4°C. How much heat was released? Assume that the heat capacity and density of the solution are the same as ...

Chemistry
write a balanced nuclear equation for the reaction that occurs when uranium-335 absorbs a neutron and undergoes fission to produce 3 neutrons, bromine-65 and another nucleus.

chemistry
2. 50.0 mL of 1 M NaOH(aq) and 50.0 mL of 1 M HNO3(aq), both initially at 18.6°C, were mixed in a Styrofoam cup calorimeter. The temperature of the solution rose to 25.4°C. How much heat was released? Assume that the heat capacity and density of the solution are the same as ...

chemistry
Using the electron configuration of nickel (Ni), identify its magnetic character. a. ferromagnetic b. paramagnetic c. no magnetic character d. diamagnetic

Chemistry
How many moles of carbon are in a 28.0g sample? I have no idea where to start

Chemistry
A sample of plant extract is subjected to thin layer chromatography using aluminum backed plates of 0.25 mm thickness. The sample extract is suspected to contain a series of related compounds with hydroxyl and ester functional groups. Suggest a suitable solvent or solvent ...

Chemistry
True or False? An identical cylinder filled with the same pressure of hydrogen contains more molecules because hydrogen molecules are smaller than oxygen molecules.

Chemistry
A student is given 2.94g of a mixture containing anhydrous MgCl2 and KNO3. To determine the percentage by mass of MgCl2 in the mixture, the student uses excess AgNO3 to precipitate the chlorides ios as AgCl Starting with the 2.94g sample of the mixture dissolved in water, ...

Chemistry pls help DR.BOB
What intermolecular forces are responsible for neoprene's stretchiness?

Chemistry
Calculate the pH of a solution made by mixing 60.0 ml of 0.80 M N2H4 (a weak base) with 50.0 ml of 0.50 M HCl. (Kb for N2H4=1.7 x 10^-6) Can I use the Henderson Hasselbach equation here?

chemistry
The radius of a strontium atom is 215 pm. How many strontium atoms would have to be laid side by side to span a distance of 2.66 mm?

chemistry
A metal x form different chlorides.If 12.7g of chloride A and 16.3g of chloride B contains 7.1g and 10.7g of chlorine respectively show that the figures agree with the law of multiple proportions. write their formular

chemistry
What is the predicted change in the boiling point of water when 4.00 g of barium chloride (BaCl2) is dissolved in 2.00 kg of water? Kb of water = 0.51°C/mol molar mass BaCl2 = 208.23 g/mol i value of BaCl2 = 3 A. 0.0016°C B. -0.0049°C C. -1.0°C D. 0.015°C

chemistry
What is the predicted change in the boiling point of water when 4.00 g of barium chloride (BaCl2) is dissolved in 2.00 kg of water? Kb of water = 0.51ÃÆÃ​€™Ãƒâ€ ​...

chemistry
3HgO→2Hg+O2 Which of the following can definitely be concluded from the equation and heat of reaction above? A. The reaction is spontaneous. B. The reaction is non-spontaneous. C. The reaction is endothermic. D. The reaction is exothermic. E. None of these.

Chemistry
How do you obtain pure crystals of sodium chloride from a mixture of sodium chloride and activated carbon powder

chemistry
A sample of ethanol 0.78g was burnes at a final temperature of 20.9°c. The mass of water is 50.0g. Calculate the standard enthalpy change of combustion of ethanol.

Chemistry
Assume that you have a liquid in a cylinder equipped with a movable piston. There is no air in the cylinder, the volume of space above the liquid is 200 mL, and the equilibrium vapor pressure above the liquid is 29.0 mm Hg. What is the equilibrium pressure above the liquid ...

Chemistry
solid sodium reacts violently with water producing heat, hydrogen gas and sodium hydroxide. How many molecules of hydrogen gas are produced when 65.4g of sodium are added to water? 2Na(s)+ 2H2O(l) -->. 2NaOH(aq) + H2(g). Can someone please explain this question and it's ...

chemistry
4.8g of Mg were burn in 3.2g of oxygen. The MgO produced at a mass of 8g what is the equation of the reaction

General chemistry
Calculate the molarity of 500.0 ml solution containing 26.5g Na2CO3

General chemistry
How many grams of potassium sulfate are needed to prepare 150 ml of a 6.50 m/v% potassium sulfate solutions

General chemistry
What is the m/m% of NaOH in a solution prepared with 40.0 g NaOH and 400.0 g of water

chemistry
Instead of oxalate anion, if we use ethylenediamine as the bidentate ligand, what would be the product? What are the donor atoms in en?

CHEMISTRY
Write a balanced ionic equation for the redox reaction in dilute acidic solution between trioxodate(v)anion (IO3) AND IODIDE ANION (I)

chemistry
The radius of a niobium atom is 131 pm. How many niobium atoms would have to be laid side by side to span a distance of 3.20 mm?

Chemistry
Density is an important property of matter. The density of 25oC dry air at sea level is 1.29 g/L. What is the mass unit for dry air? What is the volume unit for dry air?

chemistry
a certain volume of a gas 298k is heated such that its volume and pressure are now four times their original values. what is the new temperature

Chemistry
In my upcoming lab we are extracting caffeine from tea through distillation. I was wondering why adding CaCO3 helps this process? Is it due to the basic nature of CaCO3 which decreases the polarity of the caffeine, making it less reactive with water?

Chemistry
An isotope, X, of a particular element has an atomic number of 15 and a mass number of 31. Which of the following statements are true? I. X is an isotope of phosphorus. II. X has 16 neutrons per atom. III. X has an atomic mass of 30.973

Chemistry
A piece of metal has a mass of 0.010107 kg. When it was placed into a 100-mL graduated cylinder containing 30.0 mL of water, the volume of water increased to 32.3 mL. What is the density of the metal (g/mL)?

Chemistry
Sarin is a nerve gas with a chemical formula of C4H10FO2P. What is the mass of one molecule of sarin?

Chemistry
Need help with my last question! Given the following reaction: 2NH3 (g) + 5F2 (g) ---> N2F4 (g) + 6HF (g) If 4.00 g of NH3 and 14.0 g of F2 are allowed to react, how many grams of HF can be produced?

Chemistry
A 0.446-gram sample of iron ore is dissolved in HCl and the iron (Fe solid) is reduced to Fe2+. The solution is then titrated by 38.6mL of 0.105 N KMn)4. Calculate the percentage of Fe in the iron ore sample.

Chemistry
A gas mixture consists of equal masses of methane (molecular weight 16.0) and argon (atomic weight 40.0). If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr? I am coming out with 443torr, but the listed options are 80.0 torr b. 200. torr c...

Chemistry
A gas mixture consists of equal masses of methane (molecular weight 16.0) and argon (atomic weight 40.0). If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr?

chemistry
The density of diamond is 3.51g/cm^3,and the density of platinum is 21.43g/cm^3.If equal masses of diamond and platinum are transferred to equal volumes of water in separate graduated cylinders,which graduated cylinder would have the greatest volume change? can you show me a ...

chemistry
if you burned 3.0 g of magnesium and produced 5.0 g of product how much oxygen gas was used ?

chemistry
The density of diamond is 3.51 g/cm^3 and the density of platinum is 21.43g/cm^3. If equal masses of diamond and platinum are transferred to equal volumes of water in separate graduated cylinders, which graduated cylinder would have the greatest volume change? Explain or show ...

CHEMISTRY!!
What intermolecular forces are responsible for neoprene's stretchiness?

AP Chemistry Help!!
When you light a candle, the paraffin wax soon begins to melt. Paraffin wax is a covalent compound. Can you classify the melting of the wax as a chemical change or a physical change? If so, which is it? If you cannot classify it as chemical or physical, explain why not. ...

Chemistry
If 26.4 grams of nitrogen and 30.1 grams of oxygen combine to form nitrogen monoxide, how many grams of nitrogen monoxide must form? I am confused on how to do the math.

Chemistry
Determine the mass of CaCO3 in your TUMS tablet? The weight of the tablet was 0.013g Concentration of HCl was 0.1494 M Volume of HCl was 95 mL Concentration of NaOH was 0.1422 M The average amount it took to titrate was 2.13 mL I have determined that moles of HCl neutralized ...

chemistry
what mass of copper is deposited from copper sulfate when a current of 0.22 A is passed through the solution for 15 minute

Organic Chemistry
I honestly can't figure out how to draw this structure and it's especially difficult for online homework. I've used up 2 tries and only have one more left! Can someone please help? Thank you so much! CH3C≡C(CH2)3C(CH3)3

Chemistry
1) What volume of oxygen gas at 28 Celsius and 102 kPa is needed to react completely with 150 g of iron according to the following reaction. Fe(s) + O2 (g) FeO(s) 2) A bunsen burner is lit in a lab that at 24.7 Celcius and 1.07 atm. What mass of water is produced in the ...

Chemistry
The balanced equation for the synthesis of water is: 2H2 + O2 > 2H2O If I have 5.5 grams of water, at least how many grams of Oxygen gas was needed?

Chemistry
Iron (III) Oxide reacts with Aluminum to form Aluminum Oxide and Iron. If I have 255 g of Aluminum and unlimited Iron (III) oxide, how many grams of Iron will form? I am really not sure how to work with this. What does it mean when it says that the iron is unlimited, how would...

chemistry
how do you convert 7.5% w/v NaCI to mM

Chemistry
Calculate deltaH for the reaction NO (g) + O (g) ----> NO2(g) given following NO + O3 ----> NO2 + O2 deltaH=-198.9 kj O3 ---> 3/2 O2 deltaH= -142 kj O2 -----> O2(g) deltaH=495

science chemistry
Explain how Particles moves in solid lead,molten solid,gaseous lead in these three state of matter

Chemistry
A sample of metal has a mass of 24.28g, and a volume of 5.53 mL. What is the density of this metal

  1. Pages:
  2. <<Prev
  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
  16. 18
  17. 19
  18. Next>>

Homework Help: Science

Post a New Question