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Recent Homework Questions About Chemistry
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Chemistry
According to the balanced equation 6 moles of carbon dioxide will react with 6 moles of water to produce 1 mole of sugar and 6 moles of oxygen. What are the molar masses of the following compounds from the photosynthesis equation? CO2=___________g=1 mole H20=___________g=1 ...
Chemistry
Balance the photosynthesis equation: CO2+ H2O-> C6H12O6+ O2 Which i think this is Balanced: 6CO2 + 6H2O + energy-> C6H12O6 + 6O2 ? The question is this: According to the balanced equation __________ moles of carbon dioxide will react with _________moles of water to ...
chemistry
A particular form of electromagnetic radiation has a frequency of 5.42x10^15 Hz. What is the wavelength is nanometers? meters? reply in scientific notation.
Chemistry
Balance the photosynthesis equation: CO2+ H2O-> C6H12O6+ O2 Which i think this is Balanced: 6CO2 + 6H2O + energy-> C6H12O6 + 6O2 ? The question is this: According to the balanced equation __________ moles of carbon dioxide will react with _________moles of water to ...
chemistry
Estimate the wavelength (in nm) of such a proton moving at 2.81x10^8 m/s (mass of a proton = 1.673x10^-27 kg).
chemistry
(100g)(.473J/g°C)(x-62°C) =-(500g)(4.184J/g°C)(x-22°C) Q = mass•specific heat•change in temperature Can someone show me how to solve this so i can teach myself before my test on Monday ..thanks for your time
Chemistry
Find the value of delta H net for the following equation: SnBr2(s) + TiCl4(l) -> TiBr2(s) + SnCl4(l) I know that I already posted this once but I am still lost on what to do. I know that TiCl4=-804.2 and SnCl4=-511.3 but I thought that the values for SnBr2 is 0 as well as ...
Chemistry -I really need Help.
what is the mass of 4 moles of Li?
chemistry
A H atom absorbs a photon with a wavelength of 9.50 × 10^1 nm. If the energy of the final state of the H atom was -8.72 × 10^(-20) J, calculate the energy of the initial state. Express answer in scientific notation
chemistry
The molecular mass of a substance was determined by the freezing point depression technique. The minimum data required for the determination are a. delta Tf and Kf only. b. delta Tf , Kf and mass of solute. c. delta Tf , Kf , mass of solute and mass of solvent. d. delta Tf , ...
chemistry
A solution was made by dissolving 62.07 grams of a compound in 500.0 g of water. The compound was not ionic. The freezing point of the solution was measured and found to be – 1.86oC. Using the Kf value in your textbook , the molar mass of this compound can be calculated ...
chemistry
For electrolyte solutions, the __________ the concentration of the electrolyte and the __________ the ion charges, then the __________ the ion-pairing a) lower, smaller, greater b) higher, smaller, smaller c) higher, greater, greater d) lower, greater, smaller e) lower, ...
chemistry
Benzene freezes at 5.45oC. The Kf for benzene is - 5.07 oC/m. What would be the freezing point of a 0.210m solution of octane in benzene a) 1.06oC b) 4.39oC c) 6.51oC d) 10.52oC e) 5.80oC
chemistry
In comparing the phase diagram for water with that of a solution of sugar in water, all of the following decrease except a) the vapor pressure b) the boiling point c) the freezing point d) the triple point
chemistry
When 7.50 grams of iodine (I2) is added to 48.7 grams of carbon tetrachloride (CCl4), the iodine dissolves and a solution is formed. The weight percent of the iodine in the solution is a) 13.3 % b) 15.6 % c) 60.7 % d) 2.96 % e) 86.0%
chemistry
If exactly 100.0 grams of NaCl (molecular mass = 58.44 g/mol) are dissolved in 300 grams of water (molecular mass = 18.02 g/mol), the mole fraction of NaCl is a) 1.71 b) 0.0932 c) 0.250 d) 0.103 e) 4.75
Chemistry
Calculate the mass of copper and volume of oxygen (at 25 C And 760mmHg) that would be produced by passing a current of 0.5 A through a CuSO4 solution between Pt electrodes for 3 hours.
chemistry
A gas has pressure of 43 pKa. What is the pressure in mm Hg?
chemistry
What would happen if O2 were added to N2(g) + O2(g) 2NO(g) at equilibrium?
chemistry
how do you calculate the empirical formula of the barium hydroxide hydrate if a sample consists of 3.70 grams of barium hydroxide and 2.64 gras of water???
Chemistry
How do I find out I would evaporate all solvent ( dichloromethane) from mixture with water? I have less than 1500 ppm of dichloromethane in water and want to be sure if I evaporate all that stuff at 160 degrees? I got the feeling that iw would evaporate but need to support it ...
chemistry
In a nickel bath with a total volume of 1000 gallons, titration of a 50 milliliter sample with 0.1 N silver nitrate used up 10.5 milliliters to the end point. What is the concentration in ounces per gallon of the nickel chloride (NiCl2 ) in the bath?
chemistry
A 10 milliliter sample of HCl pickle is titrated with 0.2 N NaOH to a phenol-phthalein end point and it is found that 6.5 milliliters are used. What is the concentration of HCl in the Pickle in grams per liter? In weight Percent?
chemistry
Ethanol (C2H5OH) melts at -114 °C. The enthalpy of fusion is 5.02 kJ/mol. The specific heats of solid and liquid ethanol are 0.97 J/g-K and 2.3 J/g-K, respectively. How much heat (kJ) is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50 °C?
Chemistry
How many grams of sulfur (S8) must be dissolved in 100.0 naphthalene (C10H8) to make a 0.13 solution? answer in grams.
Chemistry
Why do metals tend to be malleable?
chemistry
In the formation of acid rain, sulfur dioxide reacts with oxygen and water in the air to form sulfuric acid. Write the balanced chemical equation for the reaction. (Type your answer using the format CH4 for CH4.)
chemistry
How can I group white substances into 2 groups according to their properties&list the properties of each group? Calcium carbonate, citric acid, sucrose, Phenyl salicylate, Potassium iodide,and Sodium chloride Also, which of them dissolves in water and which has solubility in ...
chemistry
How can I group white substances into 2 groups according to their properties&list the properties of each group? Calcium carbonate, citric acid, sucrose, Phenyl salicylate, Potassium iodide,and Sodium chloride Also, which of them dissolves in water and which has solubility in ...
Chemistry
What mass (grams) of sodium phosphate is required to precipitate all silver ions from 94 mL of a 0.332 M solution of silver nitrate?
Chemistry
If a 45.3-g sample of potassium nitrate is dissolved in enough water to make 225 mL of solution, what will be the molarity?
chemistry
When do you put the suffix (g) after a compound?
chemistry- pH, neutralization
What volume of NaOH was required to have neutralized the HCl. HCl + NaOH --> H2O + NaCl There no other information given in the problem except in later questions like the NaOH had 0.1 M and that there was 50.00 mL of HCl.
chemistry
A 141-mg sample was placed on a watch glass that weighed 9.203 g. What is the weight if the watch glass and sample in grams?
Chemistry 2
How many cans ( each containing 14.0 oz of propane) would be required to convert 41.7 lbs of ice at -15.0 C to water at 100 C ( the boiling point at standard pressure)
Chemistry
Determine the mass of CuSO4.5H20 needed to make 100.00mL of a .100M CuSO4.5H20 aqueous solution..
chemistry
what will be the final temperature when equal amounts of ice at-10 degree is added to water at 60 degree c
Chemistry
A metallurgist decomposes an unknown ore to the following metals. What is the chemical formula of the ore? (Show all the chemical equation and solution steps) ore = x metal products from ore decomposition: Al: 162.0 grams Sb: 730.8 grams Ag: 1,294 grams
Chemistry
How many moles of gases will be produced if we decompose 10 moles of the reactant in the following chemical equation? 3 C2H8O4Cl4 = 12 HCl (g) + 6 CO2 (g) +6 H2 (g)
chemistry
how would i set this up? chelste's diet restricts her intake of protein to 24 g per day. if she eats an 8.0 oz burger that is 15.0% protein, has she exceeded her protein limit for the day? How many ounces of a burger would be allowed for chelste?
chemistry
1. Would it be advisable to determine the freezing point of pure p-dichlorobenzene with one thermometer and the freezing point of the solution with a different one? Explain. 2. If 0.150 mole of a nonvolatile non-electrolyte solute is present in 1200g of water, what are the ...
Chemistry
The functional groups in MSG are? Carboxylic acid, carboxylate, primary amine Is this right?
Chemistry
What is the empirical of compound (X) going through the following decomposition reaction? X = sulfur + oxygen + nitrogen sulfur = 21 gr oxygen = 69.70gr nitrogen = 6.10gr
Chemistry
What are the Empirical Formulas of the following compounds? K21P7014 = Al12Ag6O5 = H2C12O24 = C12H30O60 = Dicarbon tetrachloride = Baking Soda =
Chemistry
What are the Empirical Formulas of the following compounds? K21P7014 = Al12Ag6O5 = H2C12O24 = C12H30O60 = Dicarbon tetrachloride = Baking Soda =
chemistry
if 68.0g of NH3 react with 304g of F2, how many grams of N2F4 are produced
Chemistry
What is the pH of a 0.01M solution of arginine that has a net charge of -.65?
Chemistry University One
Is it possible for a calorimeter to have a high specific heat capacity, such as 2780J? I don't know if that is a reasonable answer.
Chemistry
Why is Mo(II)nitride = MoN3 and not M02N3 Also Why is PbO2 not Pb2O4 Thanks You!
Chemistry
A 5 gram sample of a hydrate of BaCL2 was heated, and only 4.3g of the anhydrous salt remained. What percentage of water was in the hydrate?
Bio-Chemistry
These are my answers but i want to know if i have the correct ones. There is only one best answer. A. 2,2-dimethyl butane B. Cyclohexane C. cis-2-pentene D. table salt E. acetylene Axial/ equitorial hydrogents- B triple bond- C quaternary carbon- E 10 hydrogens- A A. esters B...
Chemistry
Find the value of delta H net for the following equation: SnBr2(s) + TiCl4(l) -> TiBr2(s) + SnCl4(l) I know that I already posted this once but I am still lost on what to do. I know that TiCl4=-804.2 and SnCl4=-511.3 but I thought that the values for SnBr2 is 0 as well as ...
Chemistry
Would there be any difference in "beginning percent composition" of an alcohol/H2O soln if the alcohol formed an azeotrope with water vs. if the alcohol DIDN'T form an azeotrope with water?
chemistry
the amount of heat when 65g of water at 100c until it cools to 37c
Chemistry
During a fractional distillation of a 25mL ethanol/H2O soln, it was found that first the temperature stayed constant at ~75 C for 3mL of soln, then it went up to 100 C for the rest of the soln. The first question is: Assuming that the unknown (ethanol) did not form an ...
chemistry
a certain paint has a density of 0.914 g/mL. you need to cover a wall that is 7.6 meters long and 2.74 meters wide with a layer of paint that is 0.13 mm thick. what volume of pain (in liters and gallons)is required? what is the mass (in grams and pounds) of paint layer?
chemistry
if an organic liquid has a density of 1.11 g/mL and has a measured volume of 500. mL, what mass of liquid is present?
chemistry
a chemist needs 2.00 grams of a liquid compound witha density of 0.785 g/cm^3 density. what volume of compund is required?
Chemistry
Hello, I have a question that reads, "What is the pH of a 0.01M (10mM) solution of arginine that has a net charge of -.65?" I tried using the henderson hasselbach equation, since I know the pka of arginine is 12.48. So I got pH=12.48+log(b/a) Since the net charge was...
Organic Chemistry
How many moles of hypochlorous acid are needed to react with 0.621 mol of 9-fluorenol? please help
organic chemistry
If you are given a 6.75% (wt./vol.) NaOCl solution, how many grams of NaOCl are in 100 mL of the solution? how do you do this please???
Chemistry
What neutral atom has the same number of electrons as Sc3+
chemistry
the retina of a human eye can detect light when radiant energy incident on it is at least 4.0x10^-17 J. For light that is 565 nm wavelength, how many phontons does this energy correspond to?
chemistry
You are traveling in a country that uses the metric system. Your child is sick and a nurse determines her temperature to be 40.8 ºC. What is this temperature in ºF? (1.8*40.8)+32=105.44 105 (answer with correct # of sig figs)
chemistry
A patient has 0.050 L of blood drawn and this volume of blood has a mass of 55.0 g. What is the density of the blood? Use correct number of sig figs 1.1?
Chemistry
How many moles of hypochlorous acid are needed to react with 0.151 mol of 9-fluorenol? Is 0.524 moles correct?
chemistry
An antibiotic is sold in 4.0 mL ampoules that contain 60.0 mg of drug (60.0 mg/ 4.0 mL). How many milliliters of the antibiotic should be withdrawn from the ampoule if 20 mg are to be administered to a patient?Use correct number of sig figs 0.75ml?
Organic Chemistry
How many moles of hypochlorous acid are needed to react with 0.257 mol of 9-fluorenol? Molecular weight of hypochlorous acid = 52.46 g/mol MW of 9-fluorenol = 182.22 g/mol
chemistry
Zenapax® is used as part of immunosuppressive therapy for transplant patients. The dosage is calculated on the basis of 1.0 mg/kg. What is the proper dose for a 175 lb patient? (Given: 1kg = 2.205 lbs) 175*2.205=385.875
Chemistry
The melting point of a pure solvent (kf=1.79°C/m) is -116.3°C. If 312 g of an ionic solid (i=2.6) is added to 567.7 g of the solvent, the new melting point is -101.6°C. What is the molar mass of the ionic solute?
chemistry
From what acid and what base are the following salts made: KBr, NH4NO3, and BaCl2?
chemistry
For each solution whose pH value deviated from 7.0 by at least 1.0 pH unit, give an equation accompanied by a statement which gives the reasons and/or explanation for the deviation. pH values: NaCl 6.89 NaC2H3O2 7.75 Na2CO3 11.20 Cu(NO3)3 4.73 NH4Cl 5.91 Zn(NO3)2 5.20 KAl(SO4)...
chemistry
The Ka value for HCN is 4.9x10^-10. What is the value of Kb for CN-?
chemistry
For each solution whose pH value deviated from 7.0 by at least 1.0 pH unit, give an equation accompanied by a statement which gives the reasons and/or explanation for the deviation.
chemistry
For each solution whose pH value deviated from 7.0 by at least 1.0 pH unit, give an equation accompanied by a statement which gives the reasons and/or explanation for the deviation.
chemistry
A light photon with a frequency of at least 0.0906 x 10^16 Hz is required to split apart hydrogen bromide according to the equation: HBr(g) --> H(g) + Br(g) Calculate the energy (kJ) required to break apart a mole of hydrogen bromide. Express answer in scientific notation.
chemistry
A light photon with a frequency of at least 0.0906 ~ 1016 Hz is required to split apart hydrogen bromide according to the equation: HBr(g) ¨ H(g) + Br(g) Calculate the energy (kJ) required to break apart a mole of hydrogen bromide. Express answer in scientific ...
chemistry
The energy levels the electron can occupy in the He+ ion can be calculated using the energy level equation. Calculate the frequency (Hz) of the photon emitted when the electron goes from a n= 4.00 energy level to a n= 3 energy level. Express answer in scientific notation.
organic chemistry
An unknown H2So4 sample of 25.00mL vl is titrated with 0.149 M NaOH. If 45.22mL of NaOH were needed to reach the pink endpoint, what was the molarity of the unknown acid? Show work using conversion factors????? H2SO+2NaOH --> Na2SO4+2H2O Dont know where or how to start!
chemistry
if 3.60g of NaCl is dissolved into 75.00mL of water, what is the concentration of this salt solution, in m/v%?
Chemistry
I have a question I want to make sure I'm going in the right direction. The question states give a diatomic element which is not a gas could the answer be any of the noble gases
CHEMISTRY
1) An NaOH solution of unknown concentration is titrated with HCl. 51.9 mL of 0.400 mol/L HCl will neutralize 75.0 mL of the NaOH. What is the concentration of the NaOH solution ? Record your answer in decimal notation. I think the answer is 0.277 mol/L. is that right? 2)An ...
Chemistry
Is (NH4)2 CO3 ionic or covalent?
Chemistry
Three factors control the rate of evaporation of a liquid: surface area, temperature, and strengths of intermolecular forces. More than one of the statements given described a correct effect. The statements are (1) the larger the surface area, the faster the rate of ...
Chemistry
suppose a 1.50 kg object is suspended from the end of a silicone band. when the object is pulled down and released, the band vibrates at a frequency of 2.08 s-1. calculate the spring constant of this silicone band including units.
Chemistry
The order of the boiling points for the hydrogen halides, except for HF, is HI > HBr > HCl. The reason for this order can be attributed to a) the relative covalent bond strengths. b) differences in hydrogen bonding. c) differences in dipole-dipole attractions. d) ...
Chemistry
If the concentration of a reactant is decreased, will the speed of the reaction increase or decrease? Explain. I understand that if the concentration of a reactant is INCREASED, the frequency of coliision increases, making the rate of reaction increase. How aboout when the ...
Chemistry
Which compound below would be expected to have the highest boiling point? a) CH3-CH2-CH2-CH2-CH2-CH2-CH3 b) CH3-CH2-CH2-CH2-CH-CH3 | CH3 c) CH3-CH-CH2-CH-CH3 | | CH3 CH3 d) CH3 | CH3-CH-C-CH3 | | CH3 CH3 I think its A?
Chemistry
Which compound below would be expected to have the highest boiling point? a) CH3-CH2-CH2-CH2-CH2-CH2-CH3 b) CH3-CH2-CH2-CH2-CH-CH3 | CH3 c) CH3-CH-CH2-CH-CH3 | | CH3 CH3 d) CH3 | CH3-CH-C-CH3 | | CH3 CH3 I think its A?
Chemistry
Which compound below would be expected to have the highest boiling point? a) CH3-CH2-CH2-CH2-CH2-CH2-CH3 b) CH3-CH2-CH2-CH2-CH-CH3 | CH3 c) CH3-CH-CH2-CH-CH3 | | CH3 CH3 d) CH3 | CH3-CH-C-CH3 | | CH3 CH3 I think its A?
chemistry
what is the heaviest element with a single letter symbol?
chemistry
In class, we did a decomposition reaction of sodium hydrogen carbonate, which makes water, carbon dioxide, and sodium carbonate. How do you know when sodium hydrogen carbonate is completely reacted?
chemistry
(2.60 x 10^3 x 0.897) + 2.69 (with correct # of sig figs) IS the answer 2334.89
Bio-Chemistry
Which compound is capable of donating a proton (H+)? A. Acetic acid B. Sodium hydroxide C. Acetylene D. Pentane E. Cyclohexane Which of the following statements is not true of a C-C triple bond? A. Longer bond length than a C=C double bond. B. 180 degree bond angles C. Each ...
chemistry
Ethanol has a density of 0.780 g/mL. What volume would 500. grams of ethanol occupy. Answer with correct number of sig figs
Chemistry
The following reaction has the following standard thermodynamic parameters: Reaction: C(g) + D(g)----> E(g) Delta H rxn=-26.1kJ/mol and Delta S rxn=-69.8J/(mol*K). Calculate the temperature at which the reaction becomes nonspontaneous.
chemistry
Zenapax® is used as part of immunosuppressive therapy for transplant patients. The dosage is calculated on the basis of 1.0 mg/kg. What is the proper dose for a 175 lb patient? (Given: 1kg = 2.205 lbs)
chemistry
A kitten's normal body temperature is 102ºF. Express this temperature in ºC.
chemistry
Aluminum reacts with hydrochloric acid to produce aluminum chloride and hydrogen gas. What mass of hydrochloric acid reacts when 87.7 grams of aluminum dissolves? The equation is 2Al+6HCl=2AlCl3+3H2
chemistry
You are traveling in a country that uses the metric system. Your child is sick and a nurse determines her temperature to be 40.8 ºC. What is this temperature in ºF?
chemistry
At 20 °C, chloroform (CHCl3) has a density of 1.489 g/mL. What is the mass of 7.52 mL of chloroform at 20°C?
chemistry
When 15.5 + 0.125 + 2.55 are added, the answer with the correct number of significant figures is
chemistry
An antibiotic is sold in 4.0 mL ampoules that contain 60.0 mg of drug (60.0 mg/ 4.0 mL). How many milliliters of the antibiotic should be withdrawn from the ampoule if 20 mg are to be administered to a patient?Answer with the correct number of sig figs
chemistry
A patient has 0.050 L of blood drawn and this volume of blood has a mass of 55.0 g. What is the density of the blood? Answer with the correct number of sig figs
chemistry
(3.84 x 103 x 0.764) + 1.59 answer with the correct sig figs
chemistry
How much heat (in ) is required to warm 11.0 of ice, initially at -13.0, to steam at 111.0? The heat capacity of ice is 2.09 and that of steam is 2.01
chemistry
A piper delivers 10.04, 10.02, 10.08, and 10.06 mL in consecutive trails. Find the mean volume and the average deviation from the mean...please help some responded but didn't answer the question.
chemistry
Can someone answer please Determine the boiling point of water at 698.5 mm Hg?
chemistry
A 141-mg sample was placed on a watch glass that weighed 9.203 g. What is the weight of the watch glass and sample in grams?
Chemistry - thanks
In a thin layer chromatography (TLC)experiment,the TLC plate was pre-developed in the development chamber containing the mobile phase (to remove any contaminants before use),then air dried. On the same day,the TLC plate was then spotted with the sample & standard and placed in...
Engineering/Chemistry
Milk is flowing through a heat exchanger at a rate of 2000kg/h. he heat exchanger supplies 111,600kJ/h. The outlet temperature of the product is 95C. Determine the inlet temperature of the milk. The product specific heat is 3.9kJ/(kg*C)
chemistry
determine the i value for kcl solution
Chemistry
The density of sulfuric acid is 1.82g/mL. What volume of sulfuric acid is needed to obtain 98.0g of sulfuric acid
chemistry
how much water should i add to neutralize 1000 milliliters oh ph 13
Chemistry
The following reaction has the following standard thermodynamic parameters: Reaction: C(g) + D(g)----> E(g) Delta H rxn=-26.1kJ/mol and Delta S rxn=-69.8J/(mol*K). Calculate the temperature at which the reaction becomes nonspontaneous.
chemistry
What are the acids in the house?
chemistry
A 141-mg sample was placed on a watch glass that weighed 9.203 g. What is the weight of the watch glass and sample in grams?
chemistry
A piper delivers 10.04, 10.02, 10.08, and mL in consecutive trails. Find the mean volume and the average deviation from the mean.
chemistry
A piper delivers 9.97 g of water at 20c. what volume does piper deliver?
chemistry
Determine the boiling point of water at 698.5 mm Hg.
chemistry
A man who is 5ft tall weights 140 lbs. What is his height in centimeters and his mass in kilograms?
chemistry
Suppose that 1.78 x 10^3 kg of Fe are obtained from a 5.80 x 10^3 kg sample of Fe2O3. Assuming that the reaction goes to completion, what is the percent purity of Fe2O3 in the original sample?
Chemistry
CCl3F boils at 23.8 degrees Celcius, and its molar heat of vaporization is 24.8 kJ/mol. Calculate the molar entropy of vaporization of CCl3F (l)
chemistry
For the balanced equation shown below, how many grams of O2 reacted, if 98.0 grams of HCl are produced? 2C6H4Cl2+7O2=>12CO+2H2O+4HCl
Chemistry-help needed
I have a question on thin layer chromatography (TLC). My mobile phase (i.e. developing solvent) is a mixture of 2 non-polar solvents. After preparing the mobile phase, is it necessary to pour some into the developing chamber to saturate the chamber or should we only pour the ...
Chemistry
If you are using 5.25% (mass/mass) bleach solution and you determine that the density of the bleach solution is 1.08 g/mL, how many moles of sodium hypochlorite are present in a 4.00 mL sample?
Chemistry
If you are using 5.25% (mass/mass) bleach solution and you determine that the density of the bleach solution is 1.08 g/mL, how many moles of sodium hypochlorite are present in a 4.00 mL sample?
chemistry
A 100.0 gram sample of iron at 80.0 degrees Celsius was placed in 150 grams of water at 20.5 degrees Celsius. What was the final temperature when thermal equilibrium was reached?
chemistry
At 22 degrees Celsius and a pressure of 755 mm Hg, an unknown gas was found to have a density of 4.52 g/L. When analyzed, the gas was found to consist of two elements: Boron at 78.1% and Hydrogen at 21.9%. What is the molecular formula of this unknown gas?
chemistry
Find the mass of urea needed to prepare 51.7 g of a solution in water in which the mole fraction of urea is 7.59×10−2. anyone have the same values?
chemistry
how many grams of oxygen are needed to create 437 liters of gas?
Chemistry
Calculate to four significant figures, the energy of a photon emitted when an electron falls from n=5 to n=4
Chemistry
Determine the maximum number of electrons that can have each of the following designations: 6f: 4d: 2f: 5d(yz): 3d:
Math
of 250 candidates writing a exam, 147 passed in math,150 pass in chemistry and 85 pass subjects B)calculate the number of students who pass i)pass math only ii)pass chemistry only iii)passed neither iv)pass only one subject
Chemistry
Perform the following calculations to the correct number of significant figures. (89.6-23.981)/0.0047
Chemistry - Naming Compounds
Name the following compound. Ba3Pb2 I don't really understand since both the elements are metals and usually these bonds occur with a metal and nonmetal or two nonmetals.
Chemistry
What is the empirical formula if given c-.1929 h-.01079 o-.08566 cl-.1898
Chemistry
How many grams of NaCl should be added to 1 L of water to make an isotonic solution? (molecular weight of NaCl= 58.5) Can someone please explain to me why the answer is 9 grams.
set
of 250 candidates writing a exam, 147 passed in math,150 pass in chemistry and 85 pass subjects B)calculate the number of students who pass i)pass math only ii)pass chemistry only iii)passed neither iv)pass only one subject
Chemistry
How many kilograms of water at 15oC can be heated to 95oC by burning 143 grams of methane, CH4, assuming that 100% of the heat is used to heat the water. The heat of combustion of methane is 891 kJ per mole of methane. (The specific heat of water is 4.184 J/goC.) I am not sure...
chemistry
if you had 120 grams of sugar and all of it decomposed,how many moles of water were decomposed?
Chemistry
What is the density of Li2S in grams per cubic centimeter, if the edge length of the unit cell is 5.88*10^2 pm?
chemistry
Why must thiosulfate solution be standarized every couple of days? Please explain with an equation. Thanks.
Analytical Chemistry
What is the balanced equation for oxidation of iodide ion by oxygen (O2) that occurs which produces iodine.
chemistry
how do i know if the buffering capacity of a buffer solution is lost? Is that when after I add more of an acid or base to the solution that the pH eventually goes past + or - 1 of the original solution?
chemistry
How would you go about increasing the buffering capacity of a phosphate buffer? I know that the answer is that you should increase the concentrations of the acid and base equally or increase the total volume of the buffer solution. But can someone explain why this works? Thanks.
Chemistry
1)Which compound below would be expected to have the highest boiling point? a) CH3-CH2-CH2-CH2-CH2-CH2-CH3 b) CH3-CH2-CH2-CH2-CH-CH3 | CH3 c) CH3-CH-CH2-CH-CH3 | | CH3 CH3 d) CH3 | CH3-CH-C-CH3 | | CH3 CH3 Do I use molar mass to determine which is the highest?
Chemistry
1) Three factors control the rate of evaporation of a liquid: surface area, temperature, and strengths of intermolecular forces. More than one of the statements given described a correct effect. The statements are (1) the larger the surface area, the faster the rate of ...
chemistry
Calculate the concentration of nitrate ions, NO3- , in mol dm-3, of a solution made by dissolving 2.5000 g of ferric nitrate nonahydrate in water to give 2.000 L of solution.
chemistry
V(CH3OH)= 2 litres ρ(CH3OH) = 0,80 g/ml v(O2) - ? (How much O2 is it needed to burn with 2 litres of CH3OH?)
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