# Chemistry-Thermochemistry (grade 12)

70,481 results

### Chemistry-Thermochemistry (grade 12)

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...

### chemistry-Thermochemistry (grade 12)

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....

### chemistry-Thermochemistry (grade 12)

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....

### 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.

### Chemistry-Thermochemistry (grade 12)

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...

### 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?

### 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

### ThermoChemistry

How do you find [delta]Hvap?

### 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?

### 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.

### Thermochemistry

For the combustion of 100. gm of methane, how much heat would be generated?

### Thermochemistry

3CO(g)+ Fe2O3(s) --> 2Fe(s) + 3CO2(g) + 24.7 kJ. How much heat is released when 56 grams of CO react?

### 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?

### thermochemistry

what is the formula to find the mass of propane that must be combusted to produce 188.3kj of energy?

### Science Thermochemistry

How much heat would be liberated by the combustion of 2.5 moles of C. Delta Hc C=94600 cal

### 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?

### 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...

### 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 ...

### 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 ...

### thermochemistry college

does anyone know profesor of green river community college, auburn,wa, sue critchlow ????

### 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?

### 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.

### 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

### thermochemistry

The heat ofvaporization of water at 373K is40.7kj/mol. Find q for the evaporation of 491g of water at this temperation

### 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 ...

### 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.

### 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...

### 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.

### 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?

### 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 - ...

### Chemistry - thermochemistry

Hydrogen gas (H2) is generated by the following reaction. Ca(s) + 2 HCl(aq) → CaCl2(aq) + H2(g); ΔH = −542.7 kJ/mol When this reaction takes place in a cylinder (fitted with a piston) containing 1.000 mol Ca(s), 542.7 kJ heat is lost to the surroundings. Because a gas is ...

### Thermochemistry

What volume of benzene (C6H6, d= 0.88g/ml, molar mass= 78.11g/mol) is required to produce 1.5x10^3 kJ of heat according to the following reaction? I just can't figure out what equation to use to solve this. Help, please?

### 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.

### 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.

### 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...

### 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)

### 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.

### 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).

### medical Terminology

The most easily treated tumor is A. Grade I. B. Grade V. C. Grade III. D. Grade X. A is my answer

### 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 ...

### Math - average grade

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...

### 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.

### 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...

### 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?

### 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 ...

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?

### 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

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?

### 10th Grade Chemistry

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

### 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.

### 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...

### 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?

### 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...

### 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.

### 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 ...

### 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.

### 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

### Math Word Problem

Riding on a school bus are 20 students in ninth grade, 10 students in tenth grade, 9 students in eleventh grade, and 7 students in twelfth grade. Approximately what percent of students on the bus are in ninth grade? How do I go about solving this?

### 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 ...

### 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 the 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.

### 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 ...

### 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?

### 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?

### 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

### 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 ...

### 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)

### 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?

### 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!

### literature for kids

Picture books are usually written on a __________ reading level. A. kindergarten B. first-grade C. third-grade D. fifth-grade A?

### Chemistry

Does anyone know the answers to the Chemistry unit 4 lesson 11 ( Chemical Bonding ) test ?? In 11th grade

### 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.

### 5th grade math

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 ...

### 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 ...

### 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 ...

### grade 12 chemistry

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

### 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)...

### 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?

### Thermochemistry

A piece of tin is heated to 695 °C and dropped into 158 g of water at 23.2 °C. The temperature of the system rises to 30.7 °C. What is the mass of the tin dropped into the water? (C = 0.227 J/g°C for tin, C = 4.18 J/g°C for water)

### Thermochemistry

A piece of tin is heated to 695 °C and dropped into 158 g of water at 23.2 °C. The temperature of the system rises to 30.7 °C. What is the mass of the tin dropped into the water? (C = 0.227 J/g°C for tin, C = 4.18 J/g°C for water)

### 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? /

### 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 ...

### 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 ...

### Math

In a class 85% of the student received 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 received the highest grade in all 4 subjects?

### find my grade average

-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!!!!

### 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?

### 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?

### 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?

### 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.

### 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 ___________

### 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.

### 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 ...

### 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?

### 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.

### 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 ...

### 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 ...

### 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?

### 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 ...

### Math

How many 7th grade students are expected to move by the end of the year? If 12 students actually moved, did more or fewer 7th-grade students move than expected? Justify your answer. 6th-grade # of students: 250 % moves: 2% 7th-grade # of students 200 % moves: 4% 8th-grade # of...