Saturday
May 30, 2015

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry Need Help
Given the chemical equation, Cl2 + F2 2ClF, how many moles of ClF are produced in the reaction, if 1.50 moles Cl2 are made to react with 1.75 moles F2 ? I got the answer 3.50 moles but it was wrong. Can anyone help me please.
Friday, February 27, 2015 at 2:49am

Chemistry
Propanoic acid that, along with its sodium salt, can be used to make a buffer that has a pH of 5.25. If you have 532.9 mL of a 0.250 M solution of that acid, how many grams of the corresponding sodium salt do you have to dissolve to obtain the desired pH?
Friday, February 27, 2015 at 1:09am

Chemistry Help
The theoretical yield of Cl2 that could be prepared by mixing 15.0 g of manganese dioxide (MnO2) with 30.0 g of HCl is 12.2 g. The limiting reagent was MnO2. When the reaction was run only 8.82 g of Cl2 was collected. The percent yield of Cl2 is_? a)58.8 % b)72.3 % c)29.4 % d)...
Friday, February 27, 2015 at 12:55am

Chemistry
When 0.500 moles of boron trichloride react with 1.20 moles hydrogen gas to produce elemental boron and hydrogen chloride gas, the actual yield of boron was 66.4 % of the theoretical yield. The mass of boron obtained was _____ g. Please help I'm stuck on it.
Friday, February 27, 2015 at 12:28am

chemistry
Consider a sample of a hydrocarbon (a compound consisting of only carbon and hydrogen) at 0.959 atm and 298 K. Upon combusting the entire sample in oxygen, you collect a mixture of gaseous carbon dioxide and water vapor at 0.755 atm and 375 K. This mixture has a density of 0....
Friday, February 27, 2015 at 12:21am

chemistry
You made 100.0 mL of a lead(II) nitrate solution for lab but forgot to cap it. The next lab session you noticed that there was only 84.8 mL left (the rest had evaporated). In addition, you forgot the initial concentration of the solution. You decide to take 2.00 mL of the ...
Thursday, February 26, 2015 at 11:35pm

chemistry
The rate of removal of Aspirin from the body is a first order reaction with a rate constant,k = 0.34/h How long does it takes for 87.5% of Aspirin to be removed from the body?
Thursday, February 26, 2015 at 11:03pm

chemistry
Sodium nitrate reacts with copper (II) hydroxide. I know how to write it down: NaNo3+CuOH2----> NO REACTION The problem is that I don't understand why it's no reaction I know it's double replacement and we have to look at activity series of metal to figure out ...
Thursday, February 26, 2015 at 10:56pm

Chemistry help
2. How would it be affective if there were a lot of saliva left in the gum after chewing?
Thursday, February 26, 2015 at 9:46pm

Chemistry, HELP!
Molybdenum (Mo) is a heavy metal that can have severe health effects on humans and animals. Tailings from a mining operation in Colorado have polluted surface waters used by grazing animals with Mo. Based on the following information determine the concentration of the three Mo...
Thursday, February 26, 2015 at 9:10pm

Quick chemistry help
How would I find the number of atoms in this mole statement? 12 molecules chlorine gas=_______ atoms of Cl
Thursday, February 26, 2015 at 8:19pm

Chemistry Equilibrium
1.15 g oh h2O (density 1.00 g/ml) is introduced into an empty 1.00 L container. The seled container is heated to 412 K and .150 moles of O2 (g) is present at equilibrium. A. Wrte the equilibrium expression for the reaction above. B. Calculate the equilibrium concentration (in ...
Thursday, February 26, 2015 at 6:16pm

Chemistry to DrBob222
DrBob222 You are an amazing person! I have received more help from you the past two days that I have this whole semester from my instructor! You have an amazing gift of breaking things down to understand completely! Where are you from? Do you get paid for this somehow? look me...
Thursday, February 26, 2015 at 5:11pm

solution making/ chemistry/biotech
You have 750ml's of a solution that was originally made up using a 20X stock. How much stock was used? I think the answer is 37.5 by dividing 750/20 but I am not sure
Thursday, February 26, 2015 at 3:00pm

chemistry
why does HF have a boiling point of 19°c and H2O 100°c
Thursday, February 26, 2015 at 2:30pm

Chemistry
Ok, Need some more help... This is what I have so far. 4. Urea (NH2)2CO is prepared by reacting ammonia with carbon dioxide. The byproduct is water. 637.2g of ammonia are reacted with 787.3 g of carbon dioxide. molar mass:NH3=17 CO2=44 CO(NH2)2=60.1 a. (10 points) Write a ...
Thursday, February 26, 2015 at 11:02am

Chemistry Drbob222
Dr. Bob222 Please don't get frustrated with me, I'm really trying to figure this out... UGH!! I'm starting over again... Please advise... . Consider the following chemical equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) were ...
Thursday, February 26, 2015 at 11:01am

Chemistry! Please Help!
Lime (CaO) is used to prevent SO2 from escaping smokestacks of coal burning power plants by the formation of solid CaSO4•2H2O also known as the mineral gypsum. One of the important reactions in the overall process is the dissociation of CaCO3(s). b. If a 12.0 g sample of ...
Thursday, February 26, 2015 at 10:04am

Chemistry
Ok, Need some more help... This is what I have so far. 4. Urea (NH2)2CO is prepared by reacting ammonia with carbon dioxide. The byproduct is water. 637.2g of ammonia are reacted with 787.3 g of carbon dioxide. molar mass:NH3=17 CO2=44 CO(NH2)2=60.1 a. (10 points) Write a ...
Thursday, February 26, 2015 at 2:01am

Chemistry
Dr. Bob222 Please don't get frustrated with me, I'm really trying to figure this out... UGH!! I'm starting over again... Please advise... . Consider the following chemical equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) were ...
Thursday, February 26, 2015 at 1:23am

Chemistry
A volume of 80.0mL of H2O is initially at room temperature (22.00 ∘C). A chilled steel rod at 2.00 ∘C is placed in the water. If the final temperature of the system is 21.20 ∘C , what is the mass of the steel bar? Use the following values: specific heat of ...
Wednesday, February 25, 2015 at 11:10pm

chemistry
a mixture of NaCl and sucrose that has a combined mass of 10.20g is dissolved in enough water to make up to a 250mL solution. osmotic presdure of solution is 7.32atm at 23℃. calculate the mass percent of NaCl
Wednesday, February 25, 2015 at 11:03pm

Chemistry
Make 50.0 mL of a 0.500 M solution of acetic acid (CH3COOH) from the 1.00 M CH3COOH using a 50.0 mL graduated cylinder. 1. Show your calculations and explain how you made the acetic acid solution.
Wednesday, February 25, 2015 at 10:44pm

chemistry
A sample of oxygen that occupies 2.5 × 10−6 mL at 508 mm Hg is subjected to a pressure of 1.2 atm. What will the final volume of the sample be if the temperature is held constant? Answer in units of mL
Wednesday, February 25, 2015 at 9:22pm

Quick chemistry check
Please check each of these mole statements. Correct me if I'm wrong! 1. 59g of hydrochloric acid (HCL)=____moles I got 1.6 moles 2. 4.6 moles of sodium hydroxide (NaOH)=___ grams I got 184 grams 3. 35.0 of sulfuric acid (H2SO4)=__ f.u sulfuric acid I got 2.15x10^25th power...
Wednesday, February 25, 2015 at 9:06pm

Chemistry help
given 2.01x10^23power molecules of carbon dioxide, how many moles of co2 do you have? How many grams of carbon dioxide would this be? I need help!!
Wednesday, February 25, 2015 at 8:57pm

Quick chemistry check
Indicate whether each of the following statements is true or false. 1. One mole of NH3 weighs more than one mole of H2O IS this false 2. There are equal numbers of hydrogen atoms in one mole of H2 and one mole of H20. Is this true? 3. There are more hydrogen atoms in 2 moles ...
Wednesday, February 25, 2015 at 8:35pm

chemistry
Hydrogen fluoride has a boiling point of 19 degree Celsius whereas water has a boiling point of 100 degree Celsius...... Explain
Wednesday, February 25, 2015 at 7:54pm

chemistry
The following equilibrium exists in a closed container: N2(g) + O2(g) = 2NO(g), ΔH = +181 kJ/mol. Which of the following perturbations would favor the formation of NO(g)? (practice MCAT question from The Princeton Review MCAT Science Workbook, 2009 edition) increasing the...
Wednesday, February 25, 2015 at 7:51pm

chemistry
What volume of oxygen gas can be collected at 0.565 atm pressure and 48.0◦C when 42.9 g of KClO3 decompose by heating, according to the following equation? 2 KClO3(s) ∆−−−−͛​4;2KCl(s) + 3O2(g) MnO2
Wednesday, February 25, 2015 at 7:06pm

chemistry
Suppose you have the following reaction at equilibrium: N2(g) + 3H2(g) = 2NH3(g), ΔH = −22 kcal/mol What changes are expected to occur if the temperature of the system was decreased. You may select multiple answers. The concentration of NH3(g) would decrease The ...
Wednesday, February 25, 2015 at 6:58pm

chemistry
1) C2H2O4(aq) = H+ (aq) + C2HO4- (aq); Keq = 6.5E-2 2) C2O42- (aq) + H+ (aq) = C2HO4- (aq); Keq = 1.64E+4 then what is the equilibrium constant for the following reaction: C2H2O4(aq) = 2H+ (aq) + C2O42- (aq)? Keq = 1070 Keq = 227 Keq = 2.21E-4 Keq = 3.96E-6 Keq = 6.30E-3
Wednesday, February 25, 2015 at 6:46pm

Chemistry Pre-AP
What volume of oxygen gas can be collected at 0.565 atm pressure and 48.0◦C when 42.9g of KClO3 decompose by heating, according to the following equation? 2 KClO3(s) ∆−−−−͛​4;2KCl(s) + 3O2(g) MnO2
Wednesday, February 25, 2015 at 6:45pm

Chemistry
What volume of oxygen gas can be collected at 0.565 atm pressure and 48.0◦C when 42.9 g of KClO3 decompose by heating, according to the following equation? 2 KClO3(s) ∆−→MnO2 2KCl(s) + 3O2(g)
Wednesday, February 25, 2015 at 6:27pm

chemistry
How much H2 gas at STP can be produced by the reaction 2 Na(s) + 2 H2O(ℓ)heat−→ H2(g) + 2 NaOH(aq) of 3.90 g of Na and excess water? Answer in units of L.
Wednesday, February 25, 2015 at 6:13pm

Chemistry
A solution that contains a large amount of salt and a small amount of water is said to be a _______ solution. A. unsaturated B. saturated C. dilute D. concentrated im pretty sure its C
Wednesday, February 25, 2015 at 6:09pm

Chemistry
Are solutions of the following salts acidic, basic, or neutral? For those that are not neutral, write balanced chemical equations for the reactions causing the solution to be acidic or basic. a.C5H5NHCLO4 b.NH4NO2 c.KOCL d.NH4OCL
Wednesday, February 25, 2015 at 6:07pm

chemistry
The pollutant NO is formed in diesel engines. The reaction fixes atmospheric nitrogen with oxygen to form NO. The reaction is: N2(g) + O2(g) = 2NO(g). If the equilibrium constant for this reaction at elevated temperatures is 5.60E-11, then what is the partial pressure of NO ...
Wednesday, February 25, 2015 at 6:06pm

Chemistry
The statement "matter can be neither created nor destroyed by chemical means, but it can be changed from one form to another" is the chemical law of A. definite proportions. B. atomic disintegration. C. conservation of energy. D. conservation of matter. im not sure ...
Wednesday, February 25, 2015 at 5:41pm

CHEMISTRY
Someone please tell me if I'm doing this right... It's due tonight!! Dr. Bob222, Yesterday I posted a question and you answered me with how to calculate it.. Can you tell me if I'm doing this correctly?? Please! Consider the following chemical equation: TiCl4(g) + ...
Wednesday, February 25, 2015 at 5:29pm

Chemistry
Dr. Bob222, Yesterday I posted a question and you answered me with how to calculate it.. Can you tell me if I'm doing this correctly?? Please! Consider the following chemical equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) were reacted ...
Wednesday, February 25, 2015 at 5:10pm

chemistry
Why is it that hf has a boiling point of 19°c while h2o has a boiling point of 100°c?
Wednesday, February 25, 2015 at 4:44pm

Chemistry
Can someone help me with this question? This could help me with how to do another question, similar to this, for my homework. 1.Estimate the pH of (a) 0.15 M NAHSO3 (aq) (b) 0.050 M NaHSO3 (aq) Thank you!
Wednesday, February 25, 2015 at 4:28pm

Chemistry
a 100 g sample of ice at -15 degrees celsius is heated until it is converted to water vapour at 120 degrees celsius what is the energy change?
Wednesday, February 25, 2015 at 4:15pm

Organic Chemistry
Looking down C2-C3 of 2-methylpentane, is the first newman projection staggered or eclipsed?
Wednesday, February 25, 2015 at 3:55pm

chemistry
How is the reaction quotient used to determine whether a system is at equilibrium? The reaction is at equilibrium when Q > Keq. At equilibrium, the reaction quotient is undefined. The reaction quotient must be satisfied for equilibrium to be achieved. The reaction is at ...
Wednesday, February 25, 2015 at 2:51pm

chemistry
Upon combustion, 4.30 grams sample of a compound containing only carbon, hydrogen, and oxygen produced 8.59 g of CO2 and 3.52g of H2o. what is empirical formula of the compound ?
Wednesday, February 25, 2015 at 2:32pm

Chemistry
HCl is a gas at room temperature and does not conduct electricity. Yet when dissolved in water, the solution becomes an excellent conductor. Classify HCl as metallic, ionic, molecular or covalent network, and explain why HCl would conduct electricity in an aqueous solution.
Wednesday, February 25, 2015 at 2:26pm

chemistry
I ned these classified as metallic, ionic, molecular or covalent network and two reasons why. Aluminum Ascorbic acid Graphite Paraffin Palmitic acid Sodium chloride Sucrose Water
Wednesday, February 25, 2015 at 2:26pm

chemistry
Are acids like ascorbic acid and palmitic acid ionic, molecular, or covalent network compounds
Wednesday, February 25, 2015 at 2:24pm

chemistry
Which of the following statements is not true? 1.Chemical equilibria are examples of reversible processes. 2.When multiple reaction steps are in equilibrium, then the equilibrium constant for the net reaction is the product of the individual reactions. 3.The equilibrium ...
Wednesday, February 25, 2015 at 2:21pm

Chemistry
Lets say you melted palmitic acid, paraffin, and sucrose. While they be good conductors, poor conductors, or will they not be able to conduct electricity.
Wednesday, February 25, 2015 at 2:10pm

Physical sciences(Chemistry)
Explain why the ethanoic acid have a higher boiling point than ethanol and other molecules?
Wednesday, February 25, 2015 at 1:32pm

Physical sciences(Chemistry)
Explain why ethanol has a higher boiling point than bromoethane and the hydrocarbons?
Wednesday, February 25, 2015 at 1:23pm

Chemistry
A weighed amount of sodium chloride is completely dissolved in a measured volume of 4.00 M ammonia solution at ice temperature, and carbon dioxide is bubbled in. Assume that sodium bicarbonate is formed until the limiting reagent is entirely used up. The solubility of sodium ...
Wednesday, February 25, 2015 at 1:14pm

Chemistry
A dive tank is designed and built to be safe if the difference between the pressure inside the tank and the pressure outside the tank does not exceed 12 atm. A diver has the tank filled at the dive store at a temperature of 20o C to a pressure of 10 atm. The diver places the ...
Wednesday, February 25, 2015 at 1:14pm

Chemistry
pyrite, FeS2 reactswhen it is heated strongly in the air according to the equation 4 FeS2(s) + 11 O2 rightarrow 2 Fe2O3(s) + 8 SO2(g) What volume of sulfir dioxide ( measured at room temprature and pressure) would be produced by heating 100g of pyrite in excess of air Molar ...
Wednesday, February 25, 2015 at 11:49am

11th chemistry
Give reason- Ice floats on water near the melting point. Copper is ductile and malleable but brass is not. Latent heat of fusion of solid co2 is much less than that of silicone dioxide. pls ans asap...have my exams tom.
Wednesday, February 25, 2015 at 6:17am

Chemistry
Why is it that Hydrogen fluoride has a boiling point of 19 degree celsius, whereas water has a boiling point of 100 degree celsius.
Wednesday, February 25, 2015 at 2:18am

chemistry
2KClO3-2KCl+3O2 If this reaction produced 35.2 g of KCl, how much O2 was produced (in grams)?
Wednesday, February 25, 2015 at 12:25am

Chemistry
Consider the following reaction: CO(g)+H2O(g)⇌CO2(g)+H2(g) Kp=0.0611 at 2000 K A reaction mixture initially contains a CO partial pressure of 1348torr and a H2O partial pressure of 1780torr at 2000 K. Calculate the equilibrium partial pressure of CO2. Calculate the ...
Wednesday, February 25, 2015 at 12:23am

AP Chemistry
iN A LAB, the orders of two reactants, A and B, were determined experimnetally to be 2 and 3 respectively. a. write the rate law for this reaction. c. what would happen to the rate of the reaction if A were Doubled? d. what would happen to the rate of the reaction if B were ...
Tuesday, February 24, 2015 at 11:26pm

Chemistry
Consider the following chemical equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) were reacted completely and 7.91×106g of Ti(s) was obtained in the experiment. a. Calculate the theoretical yield of Ti(s). b.What is the actual yield of Ti(...
Tuesday, February 24, 2015 at 11:24pm

Chemistry
A pharmaceutical chemist Runs a chromatography test on a substance and identifies two of its components by comparing their RF values against certain standards . if the two components have RF values of 1.0 and 0.41 and the solvent front has traveled 12.0 cm from the samples ...
Tuesday, February 24, 2015 at 10:55pm

chemistry
how many moles of hydroxide ions will be needed to react with all of the acidic hydrogens in 0.6500g of KHP?
Tuesday, February 24, 2015 at 8:50pm

chemistry
How do I calculate the average Z molar mass, 1/n (Summation) of n*M given this data: (alternate equation: MZ=Summation N*M^3/Summation N*M^2) (Ave molar mass, mass of sample): (7.5,9.6) , (12.5,8.7), (17.5, 8.9), (22.5, 5.6), (27.5, 3.1), (32.5,1.7) mili moles for repective ...
Tuesday, February 24, 2015 at 8:33pm

honors chemistry
if you obtain 10 moles of water sugar sodium chloride copper and Styrofoam will each sample have the same number of particles?
Tuesday, February 24, 2015 at 8:21pm

honors chemistry
I'm having trouble with this question in my molar mass lab. if you obtain 10 grams of water, sugar, sodium chloride, copper, and Styrofoam will each sample have the same number of particles?
Tuesday, February 24, 2015 at 8:15pm

chemistry help!!
How do I calculate the average Z molar mass, 1/n (Summation) of n*M given this data: (Ave molar mass, mass of sample): (7.5,9.6) , (12.5,8.7), (17.5, 8.9), (22.5, 5.6), (27.5, 3.1), (32.5,1.7) mili moles for repective numbers: 1.3,.7,.51,.25,.11,.052 TOTAL: 2.92 I don't ...
Tuesday, February 24, 2015 at 7:55pm

chemistry
.033597 grams of hydrogen is combined with 1.000grams of of carbon . calculate the atomic mass of hydrogen
Tuesday, February 24, 2015 at 7:09pm

Chemistry Honors
A sample of 2.0 moles of dihydrogen gas is placed in a container with a volume of 10.4 L. What is the pressure of of the gas in torr if the gas is at 25 degrees Celsius.
Tuesday, February 24, 2015 at 6:00pm

chemistry
ok i have molality is 1.05, mole fraction is 0.076, and wt% is 2.87 and solvent is C6H6 what is solute?
Tuesday, February 24, 2015 at 5:09pm

Chemistry
I have to use the given concentration of 7.03 micromoles/liters to determine the concentration for the following dilutions. 1. mL stock solution-2 mL distilled water-8 2. mL stock solution-4 mL distilled water-6 3. mL stock solution-6 mL distilled water-4
Tuesday, February 24, 2015 at 4:59pm

Chemistry 101
Sulfuric acid dissolves aluminum metal according to the following reaction: 2Al(s)+3H2SO4(aq)→Al2(SO4)3(aq)+3H​2(g) Suppose you wanted to dissolve an aluminum block with a mass of 14.9g .What minimum mass of H2SO4 would you need? What mass of H2 gas would be ...
Tuesday, February 24, 2015 at 4:54pm

Chemistry
An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of the compound gives mass percents of 31.57% Carbon and 5.30% H. The molar mass is determined by measuring the freezing-point depression of an aqueous solution. A freezing point of -5.20 ...
Tuesday, February 24, 2015 at 3:02pm

Chemistry
Calculate the final temperature (once the ice has melted) of a mixture made up initially of 75.0 mL liquid water at 29.0 Celsius and 7.0 g ice at 0.0 Celsius?
Tuesday, February 24, 2015 at 2:54pm

Chemistry
1.Chlorine gas can be produced commercially by passing an electric current through a concentrated solution of sodium chloride (brine). The unbalanced equation is NaCl(aq) + H2O(ℓ) → NaOH(aq) + Cl2(g) + H2(g). If the brine contains 163 g of NaCl, how much Cl2 can be...
Tuesday, February 24, 2015 at 2:39pm

chemistry
H2So4+NH4OH Find the complete ionic equation Find the spectator ions Find the net ionic equation I feel like my answer is wrong i tried CIE: 2H+(aq)+So42-(aq)+2H4+(aq)---> 2NH4+(aq)+So42-(aq)+H2o (l)
Tuesday, February 24, 2015 at 11:24am

chemistry
H2So4+NH4OH Find the complete ionic equation Find the spectator ions Find the net ionic equation I feel like my answer is wrong i tried CIE: 2H+(aq)+So42-(aq)+2H4+(aq)---> 2NH4+(aq)+So42-(aq)+H2o (l)
Tuesday, February 24, 2015 at 11:18am

chemistry
Suppose that the reaction of Fe3+ and SCN- produces Fe(SCN)2 (+). 5.00mL of 2.0mM Fe3+ is mixed with 5.00 mL of 2.0mM SCN-. The student finds the equilibrium concentrations of Fe(SCN)2(+) to be 0.3mM. 1.) What is the initial number of moles of each species present? 2.) What is...
Monday, February 23, 2015 at 11:37pm

Chemistry
How much heat is needed to change 3kg of copper from a solid to a liquid? Heat of fusion = 205,000 J/kg
Monday, February 23, 2015 at 11:08pm

chemistry
What is the specific heat of an object that weighs 25 g and when heated to a temp of 500K and dropped into 100mL of water changes the temp of the water from room temp (293K) to 306K? Cp of water= 4.184
Monday, February 23, 2015 at 10:39pm

Chemistry
For the reaction 4FeCl2(aq) + 3O2(g) → 2Fe2O3(s) + 4Cl2(g), what volume of a 0.650 M solution of FeCl2 is required to react completely with 8.58 × 1021 molecules of O2?
Monday, February 23, 2015 at 8:40pm

chemistry
How many milliliters of 0.316 M KOH are needed to react completely with 58.0 mL of 0.297 M FeCl2 solution to precipitate Fe(OH)2? The net ionic equation is: Fe2+(aq) + 2OH-(aq) → Fe(OH)2(s)
Monday, February 23, 2015 at 7:53pm

chemistry
An 80.0-gram sample of a gas was heated from 25 °C to 225 °C. During this process, 346 J of work was done by the system and its internal energy increased by 6365 J. What is the specific heat of the gas?
Monday, February 23, 2015 at 7:25pm

chemistry
In a constant-pressure calorimeter, 60.0 mL of 0.310 M Ba(OH)2 was added to 60.0 mL of 0.620 M HCl. The reaction caused the temperature of the solution to rise from 23.44 °C to 27.66 °C. If the solution has the same density and specific heat as water, what is ΔH ...
Monday, February 23, 2015 at 7:25pm

Chemistry
At constant volume, the heat of combustion of a particular compound is –3949.0 kJ/mol. When 1.331 g of this compound (molar mass = 141.44 g/mol) was burned in a bomb calorimeter, the temperature of the calorimeter (including its contents) rose by 3.837 °C. What is the...
Monday, February 23, 2015 at 7:24pm

Chemistry
A researcher studying the nutritional value of a new candy places a 5.80-gram sample of the candy inside a bomb calorimeter and combusts it in excess oxygen. The observed temperature increase is 2.93 °C. If the heat capacity of the calorimeter is 38.50 kJ·K–1, ...
Monday, February 23, 2015 at 7:24pm

Chemistry
Write the rate law for the reaction, expressing k(overall) in terms of k1, k2, and k3. Step 1: UV light + Cl2(g) ⇄ 2Cl(g) Fast, Endothermic Step 2: Cl(g) + O3(g) -> OCl(g) + O2(g) Slow, Endothermic Step 3: OCl(g) + NO(g) -> NO2(g) + Cl(g) Fast, Exothermic
Monday, February 23, 2015 at 7:13pm

chemistry
sodium burns in chlorine to produce sodium chloride according to the reaction: 2Na(s) + Cl2(g) = 2NaCl(s). A student is asked to predict the mass of sodium chloride produced when 71 g of sodium is placed in a container of 200 g of chorine. The container is heated until the ...
Monday, February 23, 2015 at 5:20pm

chemistry
Ideal Mixed Gas Law problems 1. What is the pressure generated by a mixture of 25.6 g SO2 and 12.6 g Ne in a container of 72.45 L and temperature of 131 K? 2. What is the pressure of a mixture of 5.80 moles Kr and 2.71 moles Xe in a container with a volume of 205.6 Liters and ...
Monday, February 23, 2015 at 4:34pm

solution making/ chemistry/biotech
You have 750ml's of a solution that was originally made up using a 20X stock. How much stock was used? I think the answer is 3.75 by dividing 750/20 but I am not sure
Monday, February 23, 2015 at 2:55pm

Chemistry
In general, do transition metals or main group elements tend to have higher melting points? According to a article, the FeCoNi alloy tended to have a uniform structure when only Fe, Co, and Ni were included. With Al and Si, however, it had more segregation in its structure. ...
Monday, February 23, 2015 at 12:23pm

Chemistry
what is the trend in the atomic radii as the atomic number increases across a period? What is the exception to this trend? I know the radius decreases as you go from left to right, but I can't figure the exception, I read somewhere that it's the noble gasses but I'...
Monday, February 23, 2015 at 9:55am

Chemistry
The density of water at 30*C is 0.9956g/mL. If the specific gravity of acetic acid is 1.040 at 30*C, what is the density of acetic acid at 30*C?
Monday, February 23, 2015 at 6:48am

CHEMISTRY
What should be observed during titration? My answer: We observe the change in color and change in turbidity of the sol'n. Am I right? Please add more things to be observed during titration. THANK YOU!
Monday, February 23, 2015 at 6:05am

CHEMISTRY
Cite three methods of analysis of a substance from a given sple by titrimetric method of analysis. My answer is: -direct method -indirect method -back titration method Is it right??
Monday, February 23, 2015 at 5:58am

chemistry
how to calculate nuclidic mass of 3He when its binding energy is 0.76 MeV
Monday, February 23, 2015 at 2:32am

chemistry
A closed container with a mixture of hydrogen, helium, and argon has a total pressure of 2.55 atm. The partial pressure of hydrogen is 0.700 atm and the partial pressure of argon is 705 mm Hg. What is the partial pressure of helium?
Monday, February 23, 2015 at 12:22am

Chemistry
what is the trend in the atomic radii as the atomic number increases across a period? What is the exception to this trend? I know the radius decreases as you go from left to right, but I can't figure the exception, I read somewhere that it's the noble gasses but I'...
Monday, February 23, 2015 at 12:12am

  1. Pages:
  2. <<Prev
  3. 9
  4. 10
  5. 11
  6. 12
  7. 13
  8. 14
  9. 15
  10. 16
  11. 17
  12. 18
  13. 19
  14. 20
  15. 21
  16. 22
  17. 23
  18. Next>>

Homework Help: Science

Members