# Posts by JOshua

Total # Posts: 702

Chemistry/please check
Calculate the amount of heat in kilojoules reased when 50 of steam at 125 C are converted to 50 grams of ice at -125 C. AHsteam = m * Cp steam * At q1= 50g * 4.184 J/g C * (125-100)C= 5.23 x 10^J q2= m * AH 50g * 5230 J/g = 2.61 x 10^5 J q3= 50g *4.184 J/g C * (100-0)C= 2.10 ...

chemistry
is this the right anser? for this problem please let me know thanks calculate the amount of heat in kilojoules released when 50 grams of steam at 125 C are converted to 50 grams of ice at -125 C so 50 grams of H2O Ti= 124 C Tf= -125 C q=? J=? q=m *Cp * At J= 50g * 4.184J/g C...

chemistry
oh i see m ok thanks

chemistry
if so then the solution will be Delta T= Kf * M T= 7.0 C/m * O.474mol/g T=3.32 C The freezing point of the solution will be 5.7 C - 3.32 C = 2.38 C please let me know if this is correct? please

chemistry
from the texbook K(f)= 5.12 C/m but from the exercise is 7.0 C/m which one should i use to solve fro the freezing point? please help

chemistry
thansk

chemistry
i need to know if I am in the right tract please let me know...I am calulating the molality of the following exercise so I could be able to apply the formula T=Kf * molality calculate the freezing point of a solution containin 12.2 grams of benzoic acid, dissolved in 250 grams...

Chemistry
calculate the freezing point of a solution containing 12.2 grams of benzoic acid, dissolved in 250 grams of nitrobenzene. the freezing point of nitrobenzene is 5.7 celsius and its freezing point depression constant is 7.0 celsius/m. please help

Chemistry
thanks I think i got it now

Chemistry
Calculate the amount of heat in kilojoules released when 50 grams of steam at 125 C are convert to 50 grams of ice at 125 C please help

Chemestry
where you got the 7.7 from? and how you calculate the molality for it. I am stuck please help

History
I just have one more question on this matter; does the Congress's power to declare treason to a person/ establish inferior courts in states pertain to the federal territories as well?

History
Thank you for your help.

History
What authority does Congress have over other states according to Article III of the Constitution? Over federal territories?

Math
Thanks drwls for the good explanation =)

Math
Hi drwls, Just wondering, does the word "under" in the question influence the question at all? Thanks for your reply! =)

Math
Hi guys, In the question "It is given that P (0, 3), Q(7, 5), R(9, -2) and S are vertices of a square. A circle A passes through the points P, Q, R and S. Find the equation of this circle. Hence or otherwise find the equation of circle B which is the image of A under the ...

Writing prompt
Hi Jherica Holland, You have posted several questions regarding the 18th century. What I suggest is for you to search "the 1800's" on Google. There are some personal recounts which you could use as reference material. Hope I helped. Thanks! :)

Chemistry
Hi Bo, we have several indicators, including litmus, universal indicator, bromothymol blue, methyl orange, and screened methyl orange. There are many, and the list can go on forever, but these are most commonly used. The best, in my case, would be universal indicator or litmus...

writeing promot on the 1800's
O_o didn't consider that haha :)

writeing promot on the 1800's
Hi brittany lasseigne, what do you need help with? There are many points of comparison you could consider jotting down. You could try to talk to grown ups who have lived through the 1800's as children. Here's some starting material for you (Please do not copy, this is ...

Math Calculus
Thanks ^^

Math Calculus
Hi, I don't have any question specifically but I'm very confused on this. In integration to find area under/above a curve, when do you integrate: 1) with respect to y 2) with respect to x 3) using x coordinates 4) using y coordinates Thanks for your help! :)

chemistry
Hi Anonymous, Truthfully speaking I don't know much about ozone cracking. However, seeing that no one has answered your query for almost two hours, I will try to help. The definition of ozone cracking as stated in Britannica Encyclopedia is as such: "Atmospheric ozone...

chemistry
Hi Lili, I'll try this one. You could add silver carbonate to the solution. A white precipitate is produced, while a colorless, odorless, gas is evolved which produces a white precipitate in limewater (calcium hydroxide). Hope I helped! :)

Wellness, puberty
might not*, spelling error.

Wellness, puberty
Hi Max, well, in short, we need the knowledge for adulthood after marrying etc. Also, this knowledge is classified as general knowledge, some might need it, some might now :) Though most do, like how many people are reliant on common knowledge

math-3rd grade
together with 1100 + 1600, 1100 - 500, and I'm not sure if you also want to include those with negative answers..

math-3rd grade
Oops, missed out some equations such as 500 + 1600, sorry about that

math-3rd grade
Hi elaine, Yup, that is all correct. Well done!

Math
Hi Tina, A palindromic number is a symmetrical form, in this case, xyx, where x has to be 2 as the number is between 200 and 300. We'll ignore the y to move on to finding the x. Create two numbers where the difference of the hundreds place = 2. For example, 9y9 and 7y7. Or...

calculus
Hi Meghan, If you differentiate a constant (i.e. any number, fraction or yeah...a constant), you always get 0. Hope I helped :)

Math
You're welcome ^^ :)

Math
Okay, we'll do it by completing the square. :) From 3x^2 + 4x = 224, x^2 + 4/3 x = 224/3 x^2 + 4/3x + 4/9 = 224/3 + 4/9 (x+2/3)^2 = 75/1/9 x + 2/3 = square root of 75/1/9 x + 2/3 = 8/2/3 or -8/2/3 x = 8 or -9/1/3( Not applicable as positive integer cannot be a negative ...

Math
Your formula is correct. Assuming you add up the 3x and x to form 4x, you have to use the general solution of a quadratic equation. Do you know how to use it? =) By the way, x should be 8 if you use it right.

Mathematics
Thanks for the help =) Clear and detailed explanation.

Mathematics
Hi there, Can someone help me with the question: "Prove that the value of 7sinx +3cos2x cannot be greater than 5/1/24 for all values of x between 0 degrees and 360 degrees" Thanks lots. =) I've already simplified 7sinx + 3cos2x into (2sinx-3)(3sinx+1).

5th grade math
i am a number less than 10.my hundreds digit is 3 more than my thousands digit,my tenths is 2 less than my hundreds and my ones is the sum of my tenths and hundreds digits.what number can i?

rounding decimals
whay is the difference between rounding decimals to the greatest to the nearest whole

ecology
WHICH WEATHER SITUATION WILL BE THE LEAST COMFORTABLE FOR A LONG DISTANCE RUNNER? A.20* CELCIUS (68f) WITH RELATIVE HUMIDITY OF 40% B. 20* CELCIUS (68f) WITH RELATIVE HUMIDITY OF 90% C.25* CELCIUS (77 f) WITH RELATIVE HUMIDITY OF 90% D.35* CELCIUS (95 f) WITH RELATIVE HUMIDITY...

biology
what is the the equation for photosynthesis?

Math
Differentiate population from sample

geometry
what are the problems?

geometry
What are if then statments .Ill need examples please .its for a project .

HELP WITH MATH
Sorry the caps lock was on. Can you help me with this pre calculus question. I'm not quite sure how to do this. Here are the instructions. Find the area between each curve and the x-axis for the given interval: y=2x^2+x+1 from x=3 to x=6

chemistry
Suggest a type of reaction and the conditions required to breakdown polyamides into their monomers.

Psychology-Opinions wanted
i love psychology

physics
What is the wavelength of a proton traveling at a speed of 6.87 km/s

trig
What kind of reflections are the following trig functions? y = 3cos(x-1) y = sin(-3x+3) y = -2sin(x)-4

trig
What kind of reflections are the following trig functions? y = 3cos(x-1) y = sin(-3x+3) y = -2sin(x)-4

trig
y = 3cos(x-1) Shift along x: Shift along y: Kind of reflection:

us history
Thanks, much appreciated, very nice of you to look.

us history
Is there any way someone can provide me with either a synopsis, or a link to a synopsis to the lincoln steffens book The struggle for self-government? Thanks

math
s^2 - s - 6 What you're looking for is a number that when you multiply it, it equals -6 and when you add them it equals -1. these values -6 and -1 are derived from the equation. so number could be --> -/+ 3, -/+ 2 but since there's only one way of getting -1 when ...

Math
( 2 3/4 miles ) / ( X feet) = ( 1 mile)/ ( 5280 feet ) then cross multiply (2 3/4 mi)*(5280 feet)= (x feet)(1 mi) (2 3/4 )(5280) = x feet that equals your total feet for 2 3/4 miles.

math
7,2 ---> 2,7 5,4 ----> 4,5 1,8 ----->8,1 9,0 -----> can't be reversed because it doesn't become a two digit number. 3,6 ----->6,3 ----------------------------------- all these two digit numbers add up to 9, and if reversed, you should subtract 72- 27= ...

chemistry
Match the correct mole ratio to the substances in the reactions below. carbon monoxide to iron in the reaction: Fe2O3 + CO ==> Fe + CO2 water to manganeese(II) chloride in the reaction: HCl + MnO2 ==> H2O + MnCl2 + Cl2 sodium to oxygen in the reaction: Na + O2 ==> ...

geography
how do i find countries with rank classes?

chemistry
When 0.627 g of Ca metal is added to 200.0 mL of 0.500 M HCl(aq), a temperature increase of 102C is observed. Assume the solution's final volume is 200.0 mL, the density is 1.00 g/mL, and the heat capacity is 4.184 J/gC. The molar heat of reaction, H rxn, for the reaction ...

math
2. since you want to know for 20 days, how much gas you waste, 20*( 1 1/2) = 30 So , you waste 30 gallons of gas in 20 days, How much money do you spend on 30 gallons of gas. 30*(\$2)= \$60 for 30 gallons of gas which covers 20 workdays)

math
1. its a basic subtraction question. (3/4)-(1/2)=1/4 you subtract because he sold it.

math
(3/4)^(-1). Just switch the fraction to 4/3 , because its the whole fraction raised to -1. if ( 3^(-1) ) / 4 ==> 1/(3*4)=1/12

math
-7^ (-2), put it divided by 1. -1/(7^2) when you place the exponent to the denominator, change the sign, same goes if you have a negative exponent on the denominator, bring it to the numerator and change the sign. -1/49

algebra
(m+5/6)= -19 (m+5/6) *6 = -19 *6 (m+5) -5= -114 -5 m= -119

pre- algebra
(5t-9/ 4 ) = 14 5t-9 =14*4 multiply 4 to both sides, and it cancels the 4 on the left side. 5t-9=56 add 9 to both sides, and it cancels on the left side. 5t=56+9 5t=65 divide by 5 on both sides t= 13

pre- algebra
Do have trouble finding t?

pre- algebra
30= new racket 30= 3x-6, where x=old racket so x=12, old racket cost 12 dollars

criminology
what are the three major kinds of crime statistics used by criminologists? What are the advantages and disadvantages of each measure of crime? What kinds of questions about crime does each measure address most usefully?

Math adding fractions
i need help!

Japanese - translate & construct sentences
Wow! Thank you so much^^

Japanese - translate & construct sentences
I need help translating the following into japanese. -Clan of the Shadow. -Village of the Shadow. -Hidden Village of the Shadow. -Country of the Shadow. -Land of the Shadow. -Second Royal Family of the Village of the Shadow This is what I have so far: #Shadow: kumori, kage, ...

Japanese (extramural: linguistics/culture/history)
|SraJMcGin| No problem!^^ Thank you very much for those links! Very interesting sources.

Japanese (extramural: linguistics/culture/history)
|Anonymous| Oh, you're right. Thanks mate! Good luck to you too. |drwls| My apologies^^ ... but the statement is meant to be taken in a personal sense (nothing foreign for me) ... Impressed that you feel so strongly about me homeland^^ Japan, very very interesting indeed...

Japanese (extramural: linguistics/culture/history)
...sorry for any of the grammatical errors... kinda in a hurry today^^

Japanese (extramural: linguistics/culture/history)
Hallo, my name is Joshua. I'm currently doing my matric in south africa, which is most unfortunate, because south africa doesn't have much to offer in terms of "foreign languages/culture." (Moving to england in a month. Perhaps it has more to offer^^) I am ...

Algerbra
w=42.5

Askk
What is the worlds tallest man

History
Was pope gregory justified in excommunicating Henry? explain?

History
What is excommunication? what role did it play in the struggle between popes and kings?

History
How does the hierachy of the catholic church compare to the hierachy of feudal society in western europe?

History
What aspects of european society did the church dominate from 1100 to 1300?

Biology
-6.86 bars

Physics 221
1. throughout a time interval, while the speed of a particle increases as it moves along the x axis, its velocity and acceleration might be: A. positive and negative, respectively B. negative and positive, respectively C. negativa and negative, respectively D. negative and ...

Physics 221
An object starts from rest at the origin and moves along the x axis with a constant acceleration of 4m/s^2. Its average velocity as it goes from x=2m to x=8m is: A. 1m/s B. 2m/s C. 3m/s D. 5m/s E. 6m/s An object is released from rest and falls a distance H during the first ...

Algebra
How do you calculate the area of a rectangle. area of a rectangle is length x width.

Math
On a grid with points R(-2,-6)& S(3,4), what is the slope of line RS? I don't know how to find the slope. Thank you. The formula for a straight line is y = mx + b m is the slope and b is the y intercept. One way is to plug in the two sets of points listed in the problem ...

Computer Science
Describe Operating systems theory and configuration at the Unix kernel/Windows registry level Describe standard operating system services (RPC, NetBIOS, etc) Describe File storage, management, and security shemes Describe command line administration of UNIX/Windows Describe ...

Ancient Civilization
What is a mixture of sand, lime and water and used as lubricant to move stones in ancient egyptian civilization? Slurry is a nice word.

ancient civilization
what is a mummy shaped amulet that held farm tools.....it starts with the letter S? Thank you for using the Jiskha Homework Help Forum. It's interesting to note that this was a crossword puzzle word! Here's the answer: These statuettes would be placed in a tomb along ...

Ancient civilization
What is a translucent stone used in floor slabs in ancient egyptian civilization? If you'll go to http://www.google.com and enter translucent stone egyptian, you'll find the answer. =) http://touregypt.net/magazine/mag06012001/magf5.htm

5th Grade Math
I need help on how to use an equation to graph? Here is an example from the text book. y=x-4 example shows x= -2 -1 1 2 y= -6 -5 -3 -2 I want know how did they show this relationship.

math
ok, but what happened to the letters? don't they remain part of the problem? also, how does 15k/20k reduce to 4/5? thanks for your help. joshua 15k/20k should reduce to 3/4 because you can take a 5 out of 15 and be left with 3 and take 5 out of 20 and be left with 4. The ...

where did bob go?
can anyone simplify and multiply the rational expressions 10m/11p x 44p/20k x 15k/8m? and then explain it to me? have patience.

math
10m/11p.44p/20k.15k/8m we are multiplying and dividing rational expressions. can ne1 help? I have no idea what you need. Your first line makes no sense. i know, it doesn't make any sense to me either...it's fractions 10m/11p times 44p/20k times 15k/8m. we have to ...

Religion
In the Christian religion,why were ashes originally sprinkled on the top of people's heads on Ash Wednesday instead of on the forehead? This site gives the history of the use of ashes on Ash Wednesday. http://www.wf-f.org/AshWed.html#anchor2360581 http://www....

chemistry
which atom has a higher potential energy? neon or flourine

calculus
Constant annual percentage growth The function gives the value of a home in dollars in the year 2000 + t. Find the constant annual percentage change in the value of the home. Give appropriate units with your answer. Again, I'm not sure what function is being referred to ...

calculus
writing an exponential equation The function gives the value of a home in dollars in the year 1980 + t. Write an equation that can be used to determine the year in which the value of the home reached \$100,000? Use ^ to denote an exponent. Do not solve the equation and do not ...

calculus
Evaluating an exponential function The function gives the value of a home in dollars in the year 1980 + t. What was the value of the home in 1988? Round your answer to the nearest whole dollar amount and give units. You would evaluate for t=8. The units should be dollars. Your...

calculus
Consider the exponential function . Which of the following best describes the the graph of g? a. Concave up and increasing b. Concave up and decreasing c. Concave down and increasing d. Concave down and decreasing The rules are +constant, concave up, - constant concave down. ...

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