Questions Asked on
January 31, 2015

chemistry
2C2H2(g) + 5O2(g)→4CO2(g) + 2H2O(g) a. Determine the enthalpy change for the reaction. ΔH = (4(393.5)+ 2(241.8)) – (2(227) + 5(0)) The enthalpy change is 2511.6. b. Determine the entropy change for the reaction. ΔS = (4(213.7)+ 2(188.7)) –
asked by Morgan 
chemistry
In the reaction below, ΔH°f is zero for ___________. Ni(s) + 2CO(g) + 2PF3(g) = Ni(CO)2(PF3)2(l) Ni(s) CO(g) Ni(CO)2(PF3)2(l) both CO(g) and PF3(g) PF3(g)
asked by danny 
chemistry
The figure shows a cube of air at pressure 1.0 atm above a hot surface on Earth. Contact with the hot surface causes the volume of the air to expand from 2.00 × 105 L to 2.20 × 105 L by the transfer of 8.2 × 106 J of heat. Assume the systems are
asked by Morgan 
Statiatics
A student ran out of time on a multiple choice exam and randomly guessed the answers for two problems. Each problem had 5 answer choices a, b, c, d, e and only one correct answer. What is the probability that she answered neither of the problems correctly?
asked by Jenny 
Chemistry
Answer the following questions about energy changes associated with heating and cooling a substance. Use the quantities in the table for your calculations. (table) Specific heat of water /4.184J/g*K dealta H vap for water /40.7 kJ/mol dealta H fus for
asked by Morgan 
algebra
The price of salt goes up by 9 cents. The old price goes up by fourfifth of new prices. Find old and new price.
asked by Anonymous 
math
what are the coordinates of the shadow cast on the xy plane by a small object placed at the point (10,7,20) assuming that the sun's rays are parallel to the vector (5,3,2)
asked by annie 
Chemistry
I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How
asked by Morgan 
chemistry
The enthalpy change for the following reaction is 483.6 kJ: 2H2(g) + O2(g) = 2H2O(g) Therefore, the enthalpy change for the following reaction is _______ kJ: 4H2(g) + 2O2(g) = 4H2O(g)
asked by danny 
chemistry
What mass of solid sodium formate (of MW 68.01) must be added to 115 mL of 0.57 mol/L formic acid (HCOOH) to make a buffer solution having a pH of 4.16? Ka = 0.00018 for HCOOH. Answer in units of g
asked by Anonymous 
Statistics
The following contingency of frequencies is based on a 5year study of fire fatalities in Maryland. For purposes of clarity, columns and rows are identified by the letters AC and DG, respectively. Blood Alcohol Level of Victim A B C Age 0.00% 0.010.09%
asked by jcukane 
chemistry
Calculate the ΔH of reaction for: C2H4(g) + H2O(l) = C2H5OH(l) if the ΔH of formation for C2H4(g), H2O(l) and C2H5OH are +52, 286 and 278 kJ/mol, respectively? Enter a numerical value below and be sure to include a minus sign if needed. The error
asked by danny 16 
georgia state history
Which political development greatly increased tensions between the American colonies and Great Britain in the years just before the American Revolution?
asked by jam 
anthropology
Why do kinship systems work? Where, if any, would you find a working kinship system within the United States? Give examples for both questions. This is my answer, am I right? Most of us are in a kinship system with spouses, children, parents, grandparents,
asked by jimmy 
algebra
The price of salt goes up by 9 cents. The old price goes up by fourfifth of new prices. Find old and new price.
asked by Anonymous 
math
Express 0.78 .as a fraction a/b where a,b,=integer
asked by Anonymous 
Physics
the charge on a pith ball was measured as +40 nC. if the charge on an electron is 1.6 x 10^19, how many electrons have been added or removed from the ball?
asked by Elena 
Calculus
Hello, I really need help on these two homework problem. >< In problem #1, I believe it is related to the exponential functions and their derivatives section...in Calculus II? So, surely there should be a ln in the solution as well? I would like a step by
asked by Aria 
physics
Three point charge are located at a line 20cm with charge q1= 3uC, q2= +4uC, q3= 7uC. Determine the magnitude of the force.
asked by ama 
chemistry
Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) gas and calcium hydroxide (Ca(OH)2). If the ΔH for: CaC2(s) + 2H2O(l) = Ca(OH)2(s) + C2H2(g) is 127 kJ, then what is the enthalpy of formation for calcium carbide? The ΔH of formation for
asked by danny 
chemistry
Given: Equation #1: 4NH3(g) + 5O2(g) = 4NO(g) + 6H2O; ΔH of reaction = 1170 kJ Equation #2: 4NH3(g) + 3O2(g) = 2N2(g) + 6H2O; ΔH of reaction = 1530 kJ Then what is the ΔH of reaction for: N2(g) + O2(g) = 2NO(g)? Enter a numerical value below and be
asked by danny 
chemistry
Welders often use acetylene torches heat up the metal. The reaction is: C2H2(g) + 2.5O2(g) = 2CO2(g) + H2O(g) Calculate the ΔH of reaction for this reaction.
asked by danny 16 
EDU 650
compare and contrast what the authors identify as 21st century skills with what you would identify 21st century skills
asked by Fay 
georgia state history
What governing body did the Georgia Charter of 1732 establish?
asked by jam 
algebra
Solve by factoring: x2 + 5x = −6 x^2 + 5x + 6 = 0 2+3 = 5 and 2x3 = 6 so (x2)(x3) = 0 then x2=0 or x3 = 0 x = 2 or x = 3 Did I do this right??
asked by slomo 
Math
I am 4digit odd number. I am greater than 7000. The digit in my hundreds place is smaller than the digit in my tens place. What number can I be if I am made up of all the digits shown below? 6827
asked by Anaqi 
Math
at a boutique, an evening gown is marked at a profit of 40% on the cost price. it is sold in a sale at 20% discount. a. Find the actual profit as a percentage of the cost price. b. if a customer bought it for $448, find i. the marked price ii. the actual
asked by Sayaka 
Physics
A bird sits at rest in the middle of a wire. The wire slopes upward at 5* from the horizontal on either side of the bird. If the wire on both sides of the bird is experiencing a tension force of 106 N, then what is the mass of the bird?
asked by Madison 
statistics
The following contingency of frequencies is based on a 5year study of fire fatalities in Maryland. For purposes of clarity, columns and rows are identified by the letters AC and DG, respectively. Blood Alcohol Level of Victim A B C Age 0.00% 0.010.09%
asked by jess 
Math
If the original number is 8.6 and the new number is 7, what is per cent decrease ?
asked by Jon 6 grade 
English, Business English, Communications
I revised this memo to approve the youattitude. Can someone tell me if I did it correctly? If I didn't what did I do wrong. I worked on this for 3 hours! Subject: Status of Building Renovations We are happy to announce that the renovation of the lobby is
asked by Miguel 
Physics
In the picture to the right, a ring pulls a box of mass m = 5.0 kg across a level table. The string pulls with a tension F = 25.0 N at an angle θ = 25˚ above the horizontal. A frictional force of 4.0 N also acts on the box. Calculate a. the normal force
asked by Madison 
elementary differential geometry
Suppose that all the tangent lines of a regular plane curve pass through some ﬁxed point. Prove that the curve is part of a straight line. Prove the same result if all the normal lines are parallel.
asked by thida 
Anthropology
In every culture, cultural constructs will be found. What are the cultural constructs found in the U.S., and how are they used to define gender in society? Compare gender constructs in Pastoralist societies. What differences do you find between the United
asked by jimmy 
Add maths form 4
The quadratic equation 2qx(x+1)8x^21, where q is a constant, has no real roots. Find the range of values of q. Answer given is 2
asked by Sha 
Physics
Particles of charge +65, +48, and −95 μC are placed in a line. The center one is L = 60cm from each of the others.Calculate the net force on the left charge due to the other two.
asked by Mary 
Criminal Justice/Judicial System
Congress has delegated the responsibility of setting the rules of practice, procedure and evidence in federal courts to the ___________ of the United States. A. federal judges B. state judiciary C. Rules Committee D. Judicial Conference *34 L03 I think
asked by Pat 
Physics
The space shuttle is in a 3e+5 m high orbit over the earth. The radius of the earth is 6.37e+6 m, the mass of the earth is 5.98e+24 kg. What is the distance from the center of the earth to the space shuttle? I don't know whether I would double the radius
asked by Carly 
chemistry
The radiator in your car uses either water or ethylene glycol (antifreeze) to remove heat from the engine and dissipate it to the outside air. If the water recirculation rate is 17.0 kg per minute of water and the water temperature leaving the engine and
asked by danny 
chemistry
What is the specific heat capacity of ethanol (C 2H 6O) if a 18.3 g sample increased 12.3 C upon the addition of 553.0 J? The units are J/(g ·K)
asked by danny 
Chemistry
How many rams of 96.5% pure NaOH pellets do you need to make 1 liter of 1.5 N NaOH?
asked by Gordon 
math
A clock was set on Monday at 8.30 a.m. On Tuesday, the following day, the clock showed 8.45 p.m. when the correct time was 8.30 p.m. How many minutes was the clock gaining in every 24 hours?
asked by kudu 
math
John and David had packets of tea to be packed into cartons. Each carton holds 46 packets. John packed 63 cartons and remained with 24 packets while David packed 54 cartons and remained with 19 packets. How many more packets of tea had John than David? =
asked by kudu 
Math
A rectangular container 45cm long and 25cm wide was full of water. After removing 22.5 liters of the water, the level of water became 4cm high. What was the height of the container?
asked by kudu 
math
In a group of 126 spectators the ratio of men to women was 3:4. What is the new ratio if 2 more men and 8 more women joined the group of spectators?
asked by kudu 
math
A rectangular plot of land measures 40m by 30m. There is a wall on one of the longer sides. Four strands of wire are to be used to fence the three remaining sides of the plot. What length of wire is required?
asked by kudu 
Chemistry
What is the enthalpy change when 25 g's of PCl5 are decomposed /\ H= 90
asked by Anonymous 
Anthropology
why the kinship system work? Answer Because it help out the people
asked by jimmy 
Calculus
Differentiate: y = (x^2 + 8x +3)^3
asked by Wes 
Pre Calculus
Can someone help me with this problem? Determine the number of positive integers less than 10,000 that can be formed from the digits 1, 2, 3, and 4 if repetitions are allowed. Thank you!
asked by Anonymous 
Anthropology
Where, if any, would you find a working kinship system within the United State
asked by jimmy 
Math
The number of women passengers in a bus was X. The number of children in the bus was three times that of men passengers but was 6 more than that of women. Write equation that shows the total number of passengers in the bus?
asked by kudu 
Math
A pill weighs 70 mg. 7/9 of the pill is the active ingredient. How many milligrams are in the part of the pill that is not the active ingredient? So if 7/9 is active that means 2/9 is not active. I did 2 divided by 9 which gives me .22 I then multiplied 70
asked by Luis 
Physics II
Please can anyone explain. Thank you. A rocket is launched vertically from ground with a constant acceleration. If the rocket emits a burst of sound every five seconds after launching, find the difference of intensity levels observed at the launching site
asked by ANA 
Math
Samuel, Elis and David sell newspapers. One day David sold 20 newspapers more than Elis who sold 10 newspapers more than Samuel. The total number of newspapers they sold that day was 140. If Elis sold y newspapers, write the equations can be used to find
asked by kudu 
math
5,280 divided by 9 = is what?
asked by Anonymous 
Statistics
The height of a bluebird was measured in centimeters. If the ruler reads 10.599 centimeters, what is the lower real limit of the bluebird's height? I know the lower limits of 10 are 9.5 or 10.5 after we go further I don't understand how to get the rest of
asked by Anonymous 
Stats
A classroom of n = 10 children has a mean score of 17.200 on a measure of hyperactivity. One new child is added to the class, and the mean hyperactivity score for the resulting classroom including all the children is 18.000. Find the value of the new
asked by Luis 
georgia state history
Which grouping lists the main reasons for European exploration? A) "God, glory, and gold" B) "Salt, silk, and spices" C) "Rum, slaves, and molasses" D) "Trade, silver, and jewels"
asked by jam 
math
on a map, the key indicates that 2.5 centimeters equals 10 miles. a road on the map runs for 30 centimeters. how long is the road?
asked by jorge 
chemistry
What is the concentration of hydrogen ions in a solution containing 0.645 M HOCN (cyanic acid) and 0.235 M (NaOCN) (sodium cyanate)? The ionization constant of cyanic acid is 3.5 × 10−4 . Answer in units of M
asked by Anonymous 
COMM/215
I would like to know if i have used properly structured sentences for the following: 49. To succeed in the new economy, workers will have to learn throughout their careers adapt to changing circumstances, and selfmotivate when needed. 50. Some students
asked by Frank 
COMM/215
I would like to know if i have used the correct grammar and punctuation in the following two sentences: 47. "Have you ever read the story, 'The TellTale Heart' by Edgar Allen Poe?" Dave asked. 48. "Did the professor say, 'Put down your pencils'?" Janice
asked by Frank 
chemistry
A buffer solution is made by dissolving 0.45 moles of a weak acid (HA) and 0.23 moles of KOH into 720 mL of solution. What is the pH of this buffer? Ka = 6.2 × 10−6 for HA. Answer in units of pH. i need the answer
asked by Anonymous 
Calculus
Compute the maximum and minimum amount of a drug remaining in a patient in the limit (that is, as time tends to infinity) given that the patient takes an 80 milligram dose once a day at the same time each day and the drug has a half life of 22 hours.
asked by Jona 
American History 1 HY1110
The Spanish, French, and English all explored America and left a lasting mark on the New World�s development. Compare and contrast the colonization methods used by each. Be sure to discuss the goals, characteristics, and lasting effects of each power's
asked by Hope 
physics II
A rocket is launched vertically from ground with a constant acceleration. If the rocket emits a burst of sound every five seconds after launching, find the difference of intensity levels observed at the launching site for the first and the second bursts of
asked by ANA 
geometry
if the lengths of the sides of one triangle are 2 inches 5 inches and 7 inches respectively in the shortest leg of a similar triangle is 4 inches what is the perimeter of the second triangle in inches?
asked by keyna 
math
what is the greatest common factor of the polynomial show? rectangle tiles that have 6x and 6 look like this: ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** !!! !!! !!! !!! !!! !!!
asked by Jason 
math
When a car makes an emergency stop on dry road, it leaves skid marks. The speed S, in miles per hour, of the car when brakes were applied is related to the length L, in feet, of the skid mark. Functional notation is needed, please help.
asked by Marcquillia 
Anthropology
Marriage patterns vary by culture themselves. In some cultures, such as in Saudi Arabia, the practice of plural marriage is accepted and promoted. This particular practice, known as polygyny, refers to a man taking more than one wife. In the United States,
asked by jimmy 
SS ANYONE HELP?
Describe significant events in the social and economic reconstruction of the South. Why are these events significant?
asked by Christina 
Ss help 8th
Compare and contrast the experiences of the Creeks and Cherokees in Georgia following the War of 1812
asked by Christina 
chemistry
The ionization constant of HA is 1 × 10−6 . What must be the ratio of [A−] to [HA] for the preparation of a buffer solution with a pH of 6.77? whats the answeer??????
asked by Anonymous 
chemistry
A buffer solution is made by dissolving 0.45 moles of a weak acid (HA) and 0.23 moles of KOH into 720 mL of solution. What is the pH of this buffer? Ka = 6.2 × 10−6 for HA. Answer in units of pH. please i need the answerf
asked by Anonymous 
Anthropology
what differences between the United States and a Pastoralist society? My answer Both of these societies had a more complex social organization and have increased specialization. Due to material surplus, labor distribution was unequal and so was social
asked by jimmy 
s
The fish didn't take , ,as they periodically teased the boys,nibble at bit,they jumped ,as the jumping within arm"s reach of the boy,were on bank.I had combine does it make sense
asked by Anonymous 
math
the point t' (4,7) is the image of point t under a transformation. if point t is (4,7) what translation could have occurred
asked by Haan 
math help
(x+5)^2  (x5)^2 is factored, it can be written as Ax where A is a whole number. The value of A is?
asked by Jim 
Program Designs
The Daily Gazette accepts classified ads in several categories. For most ads, the newspaper charges 10 cents per word for the first 50 words, and 8 cents per word for every word after that. Design Visual Logic Flowchart for a program that accepts data
asked by Joel 
Trigo
Two observers on opposite sides are 350m apart and are looking at a balloon if the angles of elevation from each observer are 30degree and 60degree respectively,how high is the balloon?
asked by Dend 
Trigo
a ship sails due north from port 90 km,than 40 km east and then 70 km north, how far is the ship from port
asked by Dend 
math  hw help
A rectangular picture is 3cm longer than its width, (x+3). A frame 1 cm wide is placed around the picture. The area of the frame alone is 42 cm^2. Find the length of the picture _______cm. _________________ ________ ! ! ! ! ! ! ! ! !x+6 ! ! ! ! ! ! !
asked by Elias 
Physics
Three people pull simultaneously on a stubborn donkey. Jack pulls eastward with a force of 68.5 N, Jill pulls with 61.3 N in the northeast direction, and Jane pulls to the southeast with 111 N. (Since the donkey is involved with such uncoordinated people,
asked by Jordan 
georgia state history
Tomochichi’s trip to England with James Oglethorpe was important because A) the English wanted to meet Oglethorpe’s Native American friends. B) it showed the goodwill between the Native Americans and the English. C) Oglethorpe wanted Native Americans
asked by jam 
math
one out of 42 high school ball players plays college ball. one out of 47 college players plays professional ball. what fraction of high school players professional ball?
asked by Anonymous 
Calculus
Write 2.445353535353... as a fraction I'm learning integrals right now and this is part of the exercises under it. Is there a trick to this? Using integrals? Thank you very much!
asked by Alex 
General Paper
"Do we expect too much from public figures?" I wrote an introduction. I agree to the question raised. Please take a look at the introduction I wrote and also comment on my draft for the next few body paragraph. I have yet add in a example to paragraph 2
asked by Sing 
MATHS
The average of two numbers is 81. The difference between the number is 26. What is the smaller number?
asked by Sarah JJ 
Natural science
What is vegetative reproduction?
asked by Vuyiseka 
chemistry
Suppose you add 92 ml of dilute acid to 46 ml of water. Both the water and acid were at room temperature (22 C) before being mixed. The temperature of the solution increased to 39 C. How much energy (in kJ) was released by the dissolution of the acid if
asked by danny 
chemistry
Suppose that your morning shower is 7 minutes long and uses 4 gallons of water per minute that is a nice 102 F in temperature. How much energy (kJ) must be used to heat the water for your shower if the water coming into your house is at 60 F? The heat
asked by danny 
Spanish
Can someone check my answers to this? I'm really confused on these practice problems. Thanks! Directions: Using informal, formal, plural and nosotros commands (use Dop's/Iop's if needed) to correctly answer the questions. The names in parathenisis are what
asked by Sophia 
Pure math,Life science,Geography and History
Hi I'm grade10 and I was wondering if you's could help Me to get a career examples after matric because my school took away our Physics for unknown reasons so insted of Physics or another subject that would help you in the future they gave us History
asked by Zenande Snyman 
Maths Problem
Please help me to solve this.... The average of two numbers is 81. The difference between the number is 26. What is the smaller number?
asked by Sarah JJ 
georgia state history
James Wright was an effective and admired colonial Georgia governor. His popularity with the colonists allowed him to A) encourage more colonists to establish communities in Georgia’s frontier. B) expand Georgia’s territory through negotiations with
asked by jam 
advanced functions
Marko rides 10 km north of his home on his mountain bike. He reaches an abandoned railroad, turns through an angle of 120° onto the railroad, and then rides another 20 km.
asked by Juhi 
Math Vector Calculus
A manufacturer sells two products, one at a price of $3000 a unit and the other at a price of $12000 a unit. A quantity q1 of the first product and q2 of the second product are sold at a total cost of $5000 to the manufacturer. Express the manufacturer's
asked by Javier 
algebra
The price of salt goes up by 9 cents. The old price goes up by fourfifth of new prices. Find old and new price.
asked by Anonymous 
math
Three pupils John, Daniel and David contributed a total of $400 for a party. John contributed $30 more than Daniel while, David contributed three times as much as John. If David contributed $x, write the equation can be used to find David's contribution?
asked by kudu 
Trigo
A flagpole 12.5m high stands at the top of a bldg. From a pt. P on the street the angle of elevation of the top of the pole is 54 degrees and the angle of elevation of the foot of the pole is 46 degrees. How high is the bldg.?
asked by Why? 
Chem
The decay constant for a radioactive isotope is 7.82 x 106 /y. What is the halflife of this isotope in years?
asked by Brooklyn 
physics
An athlete performing a long jump leaves the ground at a 27.1∘ angle and lands 7.72m away 1.What was the takeoff speed? 2.If this speed were increased by just 5.0%, how much longer would the jump be?
asked by Kelly