Friday
February 12, 2016

Number of results: 64,338

Thermochemistry determine the final temperature if 45.67 kJ of heat energy is removed from 18.5 g of H2O (g) at 122 degrees Celsius useful information sp. heat H2O (s) = 2.03 J/g(degree C) sp heat H2O (l) = 4.18 J/g(degree C) Sp heat H2O (g) = 2.01 J/g(degree C) enthalpy H Fus...
February 15, 2012 by Rose Bud

calculate enthalpy of H for the reaction N2H4(l) + 2H2O(l) -> N2(g) + 4H2)(l) Given the reactions N2H4(l) + O2(g) -> N2(g) + 2H2O(l) Enthalpy of H = -6.22.2 kJ H2(g) + (1/2)O2(g) -> H2O(l) enthalpy of H = -285.8 kJ/mol H2(g) + O2(g) -> H2O2(l) enthalpy of H = -187....
February 16, 2012 by Rose Bud

calculate enthalpy of H for the reaction N2H4(l) + 2H2O(l) -> N2(g) + 4H2)(l) Given the reactions N2H4(l) + O2(g) -> N2(g) + 2H2O(l) Enthalpy of H = -6.22.2 kJ H2(g) + (1/2)O2(g) -> H2O(l) enthalpy of H = -285.8 kJ/mol H2(g) + O2(g) -> H2O2(l) enthalpy of H = -187....
February 16, 2012 by Rose Bud

Chemistry
I need to perform a chemical demonstration on thermochemistry or kinetics or colligative properties for chemistry class. However I cannot have demonstrations involving fire.
January 12, 2010 by alex

A 65.0 g sample of 0.600 M HI at 18.46 degrees celsius is added to 84.0 g of solution containing excess KOH, also at 18.46 degrees celsius. The final temperature is 21.96 degrees celsius. Calculate the enthalpy of H for the reaction. Assume the specific heat of the solution is...
February 16, 2012 by Rose Bud

Chemistry
I have a test on the general concepts of thermochemistry tomorrow. how should i study for it since its not based on problem solving, just concepts?
October 24, 2007 by Nick

chemistry-thermochemistry
A student mixes 85.7 g of water at 68.0°C with 50.7 g of water at 24.5°C in an insulated flask. What is the final temperature of the combined water
October 5, 2008 by james

ThermoChemistry
How do you find [delta]Hvap?
March 19, 2008 by James

college chemistry-thermochemistry
A 1.50g sample of NH4NO3(s) is added to 35.0g of water in a foam cup and stirred intil it dissolves. The temperature of the solution drops from 22.7 to 19.4 degrees celcius. What is the heat of dissolution of NH4NO3, expressed in kJ/mol NH4NO3?
November 8, 2008 by maryanne

thermochemistry
Calculate the amount of heat liberated (in kJ) from 374 g of mercury when it cools from 83.7°C to 19.1°C.
October 5, 2008 by james

Thermochemistry
For the combustion of 100. gm of methane, how much heat would be generated?
September 6, 2015 by Gary

Thermochemistry
3CO(g)+ Fe2O3(s) --> 2Fe(s) + 3CO2(g) + 24.7 kJ. How much heat is released when 56 grams of CO react?
December 14, 2010 by Hannah

Thermochemistry
When 1 mol of a gas burns at constant pressure, it produces 2426 J of heat and does 6 kJ of work. What is Delta H, q, and w?
October 18, 2010 by Michelle

thermochemistry
what is the formula to find the mass of propane that must be combusted to produce 188.3kj of energy?
August 11, 2012 by Anonymous

Science Thermochemistry
How much heat would be liberated by the combustion of 2.5 moles of C. Delta Hc C=94600 cal
July 19, 2015 by Bryan Molina

chemistry
in our notes for strengths of acids and bases it says that you could add a strong/weak acid with a strong/weak base and it will give you a low, medium or high delta h. so wouldn't acids and bases be related to thermochemistry?
July 16, 2015 by will

statistics
The grades on the final examination given in a large organic chemistry class are normally distributed with a mean of 72 and a standard deviation of 8. The instructor of this class wants to assign an “A” grade to the top 10% of the scores, a “B” grade to the next 10% of the ...
March 24, 2013 by Sarah

Chem. Copper and Chromium. Random Q...
So, I have a general chemistry test. My teacher said to know... "Copper and Chromium exceptions." I have no idea what that means. I am currently learning about Thermochemistry and the Quantum Theory of an Atom. Do you have any idea what this might mean?? Thank you for any ...
November 15, 2008 by Sarah

Chemistry
please help! Is RTP in chemistry (thermochemistry and electrochemistry) referring to room temperature of 25degreeC (or 298K) and 1atm, or 20degreeC (293K) and 1atm? In my lecture notes on gas law, they stated RTP refers to 25degreeC, but in my electrochem lecture notes they ...
November 6, 2011 by Hailey

thermochemistry college
does anyone know profesor of green river community college, auburn,wa, sue critchlow ????
December 8, 2009 by eva

Thermochemistry
It takes 45.0 J to raise the temperature of an 9.70 g piece of unknown metal from 13.0 degrees C to 24.5 degreesC. What is the specific heat for the metal?
October 17, 2010 by Michelle

ThermoChemistry
If 18 g of Kr initially at 0.5 bar and 18 L is brought to 0.49 bar and 5L, what is the overall change in enthalpy of this process? Assume that Kr is an ideal gas.
December 2, 2011 by LaurenB

Thermochemistry
How many grams of water at 0 degrees C can be frozen into ice at 0 degrees C if 55.0 kJ of heat is removed? delta Hsolid= -6.01 kJ/mol
December 14, 2010 by Hannah

thermochemistry
The heat ofvaporization of water at 373K is40.7kj/mol. Find q for the evaporation of 491g of water at this temperation
April 13, 2012 by Anonymous

c++
Write a program that asks the user to input a grade that he or she received on an exam. The grade is an integer from 0 to 100 inclusive. The program should convert the numeric grade into the equivalent letter grade. Do the conversion by using a function Letter_Grade () that ...
May 18, 2012 by jermaine

Thermochemistry
Compute the amount of heat released (absolute value) when 2.3 kg of liquid ethanol is burned in excess oxygen to make carbon dioxide and liquid water.
December 3, 2011 by LaurenB

Chemistry
In a thermochemistry experiment the reaction of 0.0857 g of an unknown metal and an excess of 4.0 M HCl resulted in a 0.210 mL decrease in the volume of an ice/water mixture. Calculate the enthalpy of this reaction per 1 g of metal reacted. Needed data: density of water at 273...
December 1, 2007 by Raj

Thermochemistry
A total of 2.00 mol of a compound is allowed to react in a foam coffee cup that contains 167 g of water. The reaction caused the temperature of the water to rise from 21.0 to 24.7 degrees C. What is the enthalpy?
October 17, 2010 by Michelle

Math Lit
In a school there are 122 grade 8s, 105 grade 9s, 134 grade 10s, 109 grade 11s, 90 grade 12s. Express Each Class as a percentage of the whole school.
February 5, 2012 by Thabo

Thermochemistry
The standard enthalpy of formation of n-octane is -249.95 kJ/mol. Compute the amount of heat liberated when 5.24 g of n-octane is burned completely with excess oxygen to form carbon dioxide and liquid water.
December 4, 2011 by LaurenB

english
- Computers - English - Foreign Languages - Health - Home Economics - Math - Music - Physical Education - Science - Social Studies GRADE LEVELS - Preschool - Kindergarten - Elementary School - 1st Grade - 2nd Grade - 3rd Grade - 4th Grade - 5th Grade - 6th Grade - 7th Grade - ...
January 8, 2010 by peter

ThermoChemistry
When 19 mL of water at 22 C is combined with 18 mL of water at 64 C, what is the final temperature of the water?. The specific heat of water is 4.184 J/g/K and its density is 1.0 g/mL.
December 2, 2011 by LaurenB

chemistry
Thermochemistry: 1. Calculate the amount of heat required to decompose 3.5 moles of sodium bicarbonate. 2NaHCO3 + 129 kJ  Na2CO3 + H2O + CO2 In this question, the heat of the reaction is part of the question instead of being written beside it- (What's the difference in...
March 17, 2015 by Bethany

Thermochemistry
The enthalpy formation of ethanol, C2H5OH, is -277.0 kJ/mol @ 298.15 K. Calculate the enthalpy of combustion of one mole of ethanol, assuming that the products are CO2(g) & H2O (l).
April 18, 2011 by Morgan

Chemistry (Thermochemistry)
Is there any equation out there that links the change in enthalpy (H) to the change in cell potential/voltage (E)? Yes, but the relationship involves the Gibbs Free Energy, which is G = H - TS, snd S is the entropy change. The change in G is approximatly the change in H in ...
August 2, 2007 by Vic

MATH
there are 400 students at smith Elementary school 1/4 of the students are in fourth and fifth grade, 1/10 of the students are in grade 3, 2/8 are in second grade and 2/5 are in first grade . How many kids are in each grade? (4th and 5th have an equal amount)
March 24, 2014 by MANISH

math
I have a question I would really appreciate the answer. If 15% of my grade is 74% and 96 is 15% of my grade and 40% of my grade is a 60.5% without the final counting for 30% what is my grade? Please help thank you.
June 26, 2015 by kim

Thermochemistry
If a chalice made of pure gold weighing 1.24 kg and initially at 15 C is filled with 100.0 mL of water at 89 C, what is the final equilibrium temperature of the system? The heat capacities of water and gold are 75.29 and 25.42 J/mol/K, respectively.
December 2, 2011 by LaurenB

Does anyone know how to calculate average point grade? I have the following data: grade D - 2 students - 4,9 percent grade C - 6 students - 14,7 percent grade B - 12 students - 29,2 percent grade A - 21 students - 51,2 percent What is the average grade? This is NOT my homework...
February 17, 2010 by refy

algebra
An “A” is considered 4.0, a “B” is 3.0, a “C” is 2.0, a “D” is 1.0, and an “F” is 0. In your first semester you received the following grades. Calculate your grade point average English = credits 3.0 Grade = C Biology = credits 4.0 Grade = B Communications = credits 3.0 Grade...
September 22, 2015 by Kristen

thermochemistry
A chemical reaction takes place in a container of cross-sectional area 100 cm2 . As a result of the reaction, a piston is pushed out through 19 cm against an external pressure of 596 torr. What is the value for w for this reaction?
October 14, 2012 by valerie

Chemistry(defintions)
I need help on finding the definitions to these: Pressure being constant, the amount of heat in a chemical equation ___________. Randomness of particle measurement is called __________. Calories required to convert 1gm of liquid to vapor without a change in temperature ...
April 6, 2010 by Bill

The students of litchfield High school are in grades 9,10,11,12. Of the students , 1/4th are in 9th grade, 1/3rd are in 10th grade, 1/6th is in 11th grade and there are 300 in the 12th grade, how many students are there all together?
November 6, 2009 by stefanie coplin

Thermochemistry
A 1.00-g sample of solid calcium was burned in fluorine to give a 1.95 g sample of pure CaF2. The energy given off in this reaction was 30.3 kJ. Given this information, we can say that the heat of formation of 1 mol of CaF2 is
June 19, 2010 by joan

Thermochemistry
A sample of liquid mercury (mass 58 g and temperature 149.0 C) is poured into 79 g of H2O at 19 C. Calculate the final temperature of the mixture, assuming no heat is lost. The heat capacities of Hg and H2O are 27.98 and 75.33 J/mol/K, respectively.
December 2, 2011 by LaurenB

Thermochemistry
I'm confused about the difference between the q in q=mc(Tf-Ti) and (Delta)H, or enthalpy. What exactly does enthalpy mean and how is that different than q? (I'm also confused about what Gibbs Free Energy actually means; I know that if it's negative, the reaction is spontaneous...
December 2, 2008 by Kevin

i need help on Chemistry and i am in 7th grade i don't know how to do some problems and i would like to know how to translate statements into equation form?
January 22, 2010 by Hope

I struggle in the sciences and was wondering what I could do over the summer self studying wise to prepare for 10th grade chem?
July 7, 2011 by Wuhta

Thermochemistry
A constant pressure calorimeter having a heat capacity of 60.8 kJ/K is used to measure the energy released from burning a compound in excess oxygen to form CO2(g) and H2O(l). If the enthalpy of combustion of the compound is -2914.0 kJ/mol and the temperature of the calorimeter...
December 4, 2011 by LaurenB

math
Riding on a school bus are 20 students in 9th grade, 10 in 10th grade, 9 in 11th grade, and 7 in 12th grade. Approximately what percentage of the students on the bus are in 9th grade?
October 6, 2014 by jenna

Thermochemistry, calorimetry
The density of ice is 0.9168 g/cm3. The density of water is 0.9998 g/cm3. Calculate the difference between ΔU (internal energy) and ΔH (enthalpy) during the fusion of 2.5 moles of ice at atmospheric pressure.
November 20, 2012 by Peter

Thermochemistry
When 1.477 mole of an inorganic salt were dissolved in 1.00 L of water in a constant pressure solution calorimeter, the temperature of the calorimeter changed from 25.00oC to 24.40 oC. The total heat capacity of the calorimeter including all its contents was 2.18 kJ oC-1 What ...
June 12, 2009 by Douglas

classroom instruction
Search the Internet to locate and review your state’s educational standards for a grade level and subject that interests you, such as second-grade language arts or fifth-grade science. i need help finding information on the state of wisconsin and 1st grade P.E.
February 18, 2010 by scooby

appling middle
If the data were displayed in a circle graph, what percent of the graph would represent the seventh grade? Enrollment is Sixth grade 64, Seventh grade 64, and Eighth grade is 70
March 10, 2011 by ry

college chemistry-thermochemistry
i have one more question: I know this one has to do with hess's law but i'm not sure of how to get the enthalpy of vaporization from this? Clculate the enthalpy of vaporization of solid potassium bromide to a gas of ions, the process KBr--->K{+1}(g)+Br{-1}(g), from the ...
November 8, 2008 by maryanne

Math 157-1
Use the data in the grade-distribution Use the data in the grade-distribution table below to construct a circle graph showing the distribution of grade types in Ike’s class. Grade Frequency A 2 B 8 C 11 D 2 F 1 How would the graph change if there were twice as many of each grade?
March 19, 2010 by Tyga

Thermochemistry
Compute the change in temperature when 1.1 g of sodium chloride is dissolved in 200.0 mL of water initially at 28 C. The heat capacity of water is 4.184 J/mL/K. Neglect the heat capacity of the NaCl. Species ΔfH (kJ/mol) NaCl(aq)-407.3 NaCl(s) -411.2
December 2, 2011 by LaurenB

chemistry
I have a chemistry project where I need to make an object move using my knowledge of chemistry. The object os a small ball teh size of a large marble. It must be moved using chemistry and NOT physics (ie slope wind etc). I am 15 and in grade 11.
April 8, 2010 by Didier

Math
Kayla has a 41% grade average. Then sha takes an exam that is for 20% of her grade and gets an 100%. What is her grade now?
May 25, 2011 by Ashley

Pre algebra
Kayla has a 41% grade average. On an exam that is worth 20% of her grade she gets a 100%. What is her grade now?
May 25, 2011 by Ashley

Choosing High School Courses
I want to major in something English or History related, probably Secondary Education, International Studies, or Journalism. I am currently enrolled in chemistry and I am doing horribly. Would colleges rather see me take chemistry and get a bad grade, or would they prefer me ...
February 23, 2009 by Corinne

english
when writing the word GRADE ONE in a sentence...would it be Grade One (where there both capital) Grade one (where only grade is capital) or grade one (where none are capital)
January 13, 2008 by spelling-grammer

Thermochemistry
Suppose 23.6 g of ClF3(g) and 40 g of Li(s) are mixed and allowed to react at atmospheric pressure and 25 C until one of the reactants is used up, producing LiCl(s) and LiF(s). Using the NIST value for the enthalpy of formation of ClF3 (webbook.nist.gov), calculate the ...
December 3, 2011 by LaurenB

math(QUESTION)
Suzan has a 69 as her grade in a class. If she does a quiz worth 9% of her grade what will her grade be?
March 7, 2014 by dalia

Math
If a grade was drawn at random from the data shown below, what is the probability that the grade is not a B? Grade Frequency A 2 B 8 C 11 D 2 F 1 I think it is 1 out of 5 or 4 but I am not sure? Please help :) Thank you much!
December 5, 2010 by Shannon

literature for kids
November 27, 2015 by bev

chemistry
thermochemistry chem conceptual. i just want to check my understanding of this Say you got this: 1)A + b=c A=4.0 grams and -91.8kj evolve How do you find change of H ? I guess you convert A to grams and then shove it under the evolved heat ? ie. change of H= -91.8kj/2 mol= 2)...
August 7, 2009 by Jim_R

Chemistry
I'm not doing so well in ap chemistry. i think i'm not studying the right way. can anyone suggest how i can raise my grade? i do my homework but it doesn't seem to help.
October 14, 2007 by Grant

In the fourth grade class at Baker Elementary, 9 students are left-handed. The fifth grade has 7 left-handed students and the sixth grade has 6. The number of students in the fourth grade is 3 times the number of left-handed students in the class. The sixth grade has 3 more ...
December 1, 2013 by Stephon

Math
At Jefferson School, both 6th grade & 7th grade classes take a math test. The average score for the 6th grade is 80 and for the 7th grade is 90. If there are twice as many students, in the 7th grade as there is in the 6th grade, what is the average test score for both grades ...
January 14, 2016 by Sidney

explain the concept of a “stock solution” and standard solutions as if you were explaining it to a friend who is not studying chemistry.
April 30, 2013 by michael

Math
A student needed to get a final grade of 90 to get a grade of A for the semester. He scored 83, 85, 92, 86, and 87. If the last two scores would be counted as one score. What is the least grade the student would need to get to get a final grade of A? Is the answer 45?
August 13, 2015 by Kareen

Math
A student needed to get a final grade of 90 to get a grade of A for the semester. If the last two scores would be counted as one score. What is the least grade the student would need to get to get a final grade of A? Is the answer 45? /
August 13, 2015 by Kareen

Math
Use the data in the grade-distribution table below to construct a circle graph showing the distribution of grade types in Ike’s class. Grade..Frequency A......2 B......8 C......11 D......2 F......1 How would the graph in Exercise 7 change if there were twice as many of each ...
October 27, 2009 by Anonymous

Math
Use the data in the grade-distribution table below to construct a circle graph showing the distribution of grade types in Ike’s class. Grade..Frequency A......2 B......8 C......11 D......2 F......1 How would the graph in Exercise 7 change if there were twice as many of each ...
November 1, 2009 by Anonymous

Math
In a class 85% of the student recieved the highest grade in English Literature, 80% in Math, 75% in History, and 30% in Chemistry. About what percentage of the students could you say for sure that they recieved the highest grade in all 4 subjects?
October 15, 2009 by Kim

-10% of my grade *82 -20% of my grade *100% *100% *100% *100% *100% *100% *100% *100% *82% -30% of my grade none -40% of my grade *76% reply as soon as possible. thank you!!!!
April 18, 2010 by magy

Chemistry-help needed
Can we use an ACS/AR grade chemical for UV spectrophotometric analysis? Or is it a must to use a chemical that is specially designated (SpectrAR grade) for UV analysis?
February 21, 2011 by candy

Thermochemistry Ap Chem homework
Any help would be great, even if it is just a way to start or a formula. Calculate the heat necessary to convert 10.0 g of water (just melted) at 0 degrees Celcius to water at 20 degrees Celcius, assuming that the specific heat remains constant at 1 cal/gram degrees celcius.
November 15, 2010 by Chris

ThermoChemistry
Calculate the final temperature of solution when 10 g of oxalic acid, (COOH)2(s), is dissolved in 110.0 mL of water that is initially at 26 C. The enthalpies of formation of oxalic acid in the solid and aqueous phases are -826.8 and -818.8 kJ/mol, respectively. The heat ...
December 2, 2011 by LaurenB

Chemistry-help needed
Can we use an AR grade chemical for UV spectrometric analysis? Or is it a must to use a chemical that is specially designated (SpectrAR grade) for UV analysis?
February 17, 2011 by candy

Chemistry-pls help
Can we use an AR grade chemical for UV spectrophotometric analysis? Or is it a must to use a chemical that is specially designated (SpectrAR grade) for UV analysis?
February 17, 2011 by candy

Biochem
November 13, 2014 by Pop

Math
A coffee dealer mixed 12 pounds of one grade coffee with 10 pounds of another grade of coffee to obtain a blend worth \$54. He then made a second blend worth \$61 by mixing 8 pounds of the first grade with 15 pounds of the second grade. Find the price per pound of each grade.
October 21, 2012 by Jamese

Chemistry
In lab we did thermochemistry, where we are supposed to find the heats of solution, heat change of calorimeter and molar heat solution of the salt. I calculated that the calorimeter constant for the water we had was 883.194 Joules. We took 1/10 of a mole of NH4Cl and tried to ...
October 31, 2010 by Rani

maths
The probabilities of a student getting grade A, B, C and D are 0.2, 0.3, 0.15 and 0.35 respectively. Then the probability that the student gets 1) At least C grade is __________ 2) At most C grade is ___________
March 10, 2011 by Sharon

Math
If you are getting a B in everything else in this class but you don't do any of the news item write ups(which are 9% of your grade, then will your final grade be a B? If not a B, then what will your final grade be?
September 2, 2011 by Jenna

mathematics concepts
Fraction symbols can usually be safely introduced A. at the beginning of third grade. B. near the end of first grade. C. near the end of third grade. D. at the beginning of second grade. my answer is c.
February 21, 2015 by Brittney

Math (trigonometry)
MONDAY  December 3, 2012 SCHOOL SUBJECTS Art Business Computers English Foreign Languages Health Home Economics Math Music Physical Education Science Social Studies GRADE LEVELS Preschool Kindergarten Elementary School 1st Grade 2nd Grade 3rd Grade 4th Grade 5th Grade 6th ...
December 3, 2012 by Sammy

Math
If Brittany has a 49.7% grade average then for her final exam that is worth 20% of the grade and she gets a 90% what would her final grade be?
May 31, 2011 by Anonymous

Chemistry
I would really appreciate some help with this thermochemistry problem! I'm really confused as to why I keep getting the wrong answers... I have gotten w=-1.305kj and energy change = 78.13kj... both of which were marked wrong. Here's the question: The oxidation of copper(I) ...
November 3, 2013 by DC

working with data
josephs final averages in science class are shown in the table below. homework % toward final grade-20% average-93 quizzes % toward final grade-20% average-92 tests % toward final grade-40% average-85 final exam % toward final grade-20% average-? what is the minimum score ...
February 24, 2008 by mike

chemistry
where can i find printable worksheets from prentice hall for chemistry? I looked, but could not find any from PH online for any grade level. nor did I.
May 7, 2007 by lily

math
Allie noticed that to get her test grade, she could take Valerie's grade, multiply it by 2 and subtract 15. If Valerie's test grade was x, how would you write Allie's test grade?
December 4, 2014 by zycuria

Chemistry
I just took my Chemistry midterm, and would like to know how to calculate my grade on the midterm with the curve. MEAN = 8.9 STANDARD DEVIATION = 2.9 MY SCORE = 7 Thank You!
October 12, 2010 by Anonymous

Chemistry
How is Surface catalyst(heterogeneous) and homogeneous catalyst different? I'm in 10th grade chemistry and I don't understand it.
May 24, 2011 by Kat

math
the grade of a road is its slope given as a percent. for example, a road with a 6% grade has a slope 6/100. it rises 6 feet for every 100 feet of horizontal run. describe a 100% grade. Do you think you could drive up it?could you walk up it? Is it possible for a grade to be ...
November 14, 2011 by manal HELP ME

There are 33 students in the band. There are 6 more fifth-grade students than third-grade students. There are an equal number of third- and fourth-grade students. How many third-grade students are in the band?
October 8, 2008 by Kristina

physics-energy conservation
some people refer to heat as "low grade energy. a)how is low grade energy different from high grade energy? b)give two example of high grade energy When heating a cup of tea, which would be preferable...a stove with a burner on top, or a heating pad? High grade energy is ...
May 8, 2007 by Emma

math / linear programming
Two factories manufacture 3 different grades of paper. The company that owns the factories has contracts to supply at least 16 tons of low grade, 5 tons of medium grade, and at least 20 tons of high grade paper. It costs \$1000 per day to operate the first factory and \$2000 per...
January 2, 2007 by Tim

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