# Posts by Erin

Total # Posts: 706

**Chem**

Ooops did not mean to post this twice!

**Chem**

Calculate the enthalpy change in the reaction of H2 with F2 to produce HF. The H–H and F–F bond energies are 436 and 155 kJ/mol, respectively, and the H–F bond energy is 567 kJ/mol H2 (g) + F2 (g) --> 2HF (g)

**Chem**

Calculate the enthalpy change in the reaction of H2 with F2 to produce HF. The H–H and F–F bond energies are 436 and 155 kJ/mol, respectively, and the H–F bond energy is 567 kJ/mol H2 (g) + F2 (g) --> 2HF (g)

**Stat 214 **

Three identical chips, each with 0 on one side and 1 on the other, are to be tossed simultaneously. A. writes the sample space. B. what is the probability of observing the sum of the face-up numbers to equal to 2? C. What is the probability of observing the sum of the face up ...

**math**

Suppose you put $2000 in a savings account at an APR of 8% compounded quarterly. Fill in the table below. (Calculate the interest and compound it each quarter rather than using the compound interest formula. Round your answers to the nearest cent.) Quarter Interest Earned ...

**Chemistry**

A pediatrician prescribes the antibiotic amoxicillin to treat a child suffering from an ear infection. The prescribed dose is to be 72.1 mg of drug per kilogram patient body mass per day. The drug is to be administered twice each day in the form of a liquid containing 126.0 mg...

**Chem**

Suppose a runner completes a 10K (10.0 km) road race in 42 minutes and 15 seconds. What is the runner's average speed in miles per hour?

**Social Studies**

The constitution gave more power to the states

**chemistry**

if 5.76 grams of co2 forms when 4.00 grams of c2h6 reacts, what is the percent yield for 2c2h6+7o2=4co2+6h2o

**Chemistry **

How many grams of CaCl2 are needed to prepare 25.0 mL of .500 M solution? and What volume of 12.00 M HCL is needed to prepare 150.0 mL of .500 M HCL?

**Chemistry please help!**

Calculate (triangle)H for the following gas-phase reaction: 2 H-C (3dashes) C-H + 5 O=O --> 4 O=C=O = 2 H-O-H -Using bond energies

**Chem Help!!!**

A 1.00 mL aliquot of solution A was diluted to 50.00 mL using 0.02 M Fe(III), forming solution B (reaction 2) By looking at this how many moles of sodium salicylate were in the 1.00 mL aliquot used to prepare solution B?

**Chemistry**

The spectrophometer was used to measure the absorbance of each of a series of [FeSa]+ solutions. A standard curve was construnceted by plotting the absorbance vs. concentration (M). The slope and y-intercept were found to be 1496 M-1 and .003, respectively. An aspirin sample ...

**Chemistry**

A tablet containing calcium carbonate and fillers with a mass of 1.631 g was dissolved in HCl. After the fillers were filtered out, the HCl was neutralized by adding sodium carbonate. The resulting precipitate was pure calcium carbonate (with the fillers removed). The solid ...

**Chemistry**

Given the reaction: Fe2SiO4 (s) + 2 H2CO3 (aq) ---> 2 FeCO3 (s) + H4SiO4 (aq) how many grams of Fe2SiO4 (s) are required to completely react with 55.0 mL of .500 M H2CO3 (aq) ?

**Chemistry**

Given the reaction: Fe2SiO4 (s) + 2 H2CO3 (aq) ----> 2FeCO3 (s) + H4SiO4 (aq). How many grams of Fe2SiO4 are required to completely react with 55.0 mL of .500 M H2CO3 (aq)?

**Chem**

Suppose a student diluted and titrated a bleach unknown exactly as described in the experimental procedure, except only a single titration was performed which required 16.22 mL of 0.100 M Na2S2O3. Calculate the number of moles of ClO- in the sample titrated.

**Chemistry**

How would I calculate the number of moles in CIO- from the sample titrated also?

**Chemistry**

Suppose a student diluted and titrated a bleach unknown exactly as described in the experimental procedure, except only a single titration was performed which required 16.22 mL of 0.100 M Na2S2O3. Calculate the number of moles of Na2S2O3 used in the titration.

**Chem**

Could you explain the second part more please?

**Chem**

Which of the following salts is water soluble? AlCl3, Li2SO4, BaC2O4, NaF, NiS, FeBr2, (NH4)2CO3, Zn(NO3)2, Na3PO4, Mg(OH)2, Ca(CH3CO2)2. Also specify the concentration of each ion in solution for the following: .10 M AlCl3 (aq) and .15 M (NH4)2SO4 (aq)

**Chemistry**

How many mols are there?

**Chemistry**

Assuming that the unknown acid sample in question 1 had a mass of 0.177 g, what is the molar mass of the unknown acid?

**Chemistry**

Suppose that 16.41 mL of 0.0512 M NaOH were required to titrate a sample of unknown acid. How many moles of NaOH were used?

**Chemistry**

We will calculate the amount of acid to use in each titration. Assume that you are using 0.0512 M NaOH(aq). A good volume of NaOH(aq) to use per titration is 15 mL. From this molarity and volume, the moles of NaOH can be calculated. Since the unknown acid is monoprotic, this ...

**Grammar**

But in my class we have to write our intro first and she yells at us for going further.

**Grammar**

Also my biggest similarity is how the state sets standards of what should be taught. But my two main differences are funding and how you have to be zoned for a specific school for public schools but no private.

**Grammar**

For right now I need help writing my intro paragraph. I also have to write a thesis and I do not understand how to do that.

**Grammar **

I am writing a compare and contrast essay between private school and public school can you help me write it

**Chemistry**

I believe the answer is 2.75grams of Oxygen Gas

**Chemistry**

The balanced equation for the synthesis of water is: 2H2 + O2 > 2H2O If I have 5.5 grams of water, at least how many grams of Oxygen gas was needed?

**Chemistry**

Iron (III) Oxide reacts with Aluminum to form Aluminum Oxide and Iron. If I have 255 g of Aluminum and unlimited Iron (III) oxide, how many grams of Iron will form? I am really not sure how to work with this. What does it mean when it says that the iron is unlimited, how would...

**Geometry**

Carlos is making cookies. The recipe calls for 1 cup of sugar for every 3 cups of flour. Carlos has only 2 cups of flour. How much sugar should Carlos use?

**Math 160**

The position function of an object moving along a straight line is given by s = f(t). The average velocity of the object over the time interval [a, b] is the average rate of change of f over [a, b]; its (instantaneous) velocity at t = a is the rate of change of f at a. A ball ...

**pre calculus work**

given f(x)= 5x+4/5x^2+4x and g(x) = 1/x a. determine the domains of f(x) and g(x) b. simplify f(x) and find any vertical asymptotes c. explain how the two functions differ I have absolutely no idea how to answer this question - can you please help me to figure it out?!

**Health**

_____are the result of an injury to a ligament DOMS Muscle sprain Muscle strain*** Overuse injury _______ Is the result of an injury to either a muscle or a tendon DOMS Muscle sprain*** Muscle strain Overuse injury

**Health**

a person can become dehydrated when wearing heavy clothing during aerobic exercise in warm weather true** false

**Math**

Well since I don't see the two triangles I can only use my imagination and take a guess. I would say square or rectangle

**English**

Read the following passage "I don't know anything," he said, "except that I'm beginning to be sorry we bought that room for the children. If children are neurotic at all, a room like that -" "It's supposed to help them work off their ...

**English**

thanks!

**English**

Against which American value did the Beat generation of writers react? equality freedom individualism traditionalism***

**Math**

You charge $3.75 an hour for babysitting plus $5 for fixing lunch. How much did you make last saturday ?

**HUMAN DEVELOPMENT**

The Seattle longitudinal study of cognitive development discovered that, among older people,

**Physics**

Don't forget that torque=I(alpha), so multiply mg sin(theta) and ma both by r so you'll be in the same units.

**Maths lit,life science,agriculture,geograph**

math is very lit btw

**Maths lit,life science,agriculture,geograph**

which what..?

**science**

the density of an object with a volume of 60.0 mL and a mass of 400.0g is___? a. 0.150g/mL b. 2.89g/mL c. 5.50 g/mL or d. 6.67 g/mL

**Math**

It's the the third link, it'll say "One-step addition & subtraction equations" I hope this helps.

**Math**

You have to do the opposite operation! It's a little confusing to write, so google this: " Khan Academy one step equation fraction " He's really easy to follow along with!

**Social Studies**

Thank you! I'll stick with the first two.

**Social Studies**

Choose two famous individuals to research that lived between 1820 and 1860. Keep in mind—your famous Americans MUST have DIFFERENT opinions on the SAME topic. Can you help me choose the two different individuals? Here's a list that I can choose from: Andrew ...

**Physics**

An electron travels at a uniform speed of 2.50 × 106 m/s toward the top of this page. It then enters a uniform magnetic field and experiences a maximum force of 5.15 × 10-8 N that points toward the right of the page. What is the magnitude of the magnetic field? ...

**Math**

The laurelwood pta is presenting it's 5th annual talent show and Kate is collected tickets at the door the gym is filled with 215 students and adults. Students tickets are .50 and adults tickets are 2.00. If Kate collected 250.00. How many adults and how many students ...

**social studies**

so what are the real answers

**Physics**

A pilot flies out of Cleveland and sets his compass due North. He maintains an airspeed of 250 km/hr. After 30 minutes he finds that the plane is 200 km north and 40 km west of the starting point. What is the velocity of the wind? I've made my triangle and found the ...

**English (EXTREMELY URGENT)**

I gave up and guessed got it right and it was D

**English (EXTREMELY URGENT)**

I had C as my back up what about that

**English (EXTREMELY URGENT)**

Hip Hop Planet, James Mcbride, I think its A

**English (EXTREMELY URGENT)**

Please help he answer this one question. Which detail best describes why the author discusses the history of rap music. To show the extreme poverty of certain regions To explore the tension amongst certain cultural groups To expose events that are rarely discussed To give the ...

**Chemistry**

the answer is b)

**Precalculus**

How many ancestors have you had in the six generations preceding you? (Assume no unusual circumstances such as duplicate ancestors.)

**Statistics**

It is estimated that heights of adult men are normally distributed with a mean of 70 inches and a standard deviation of 3.5. In one state, the law requires a person to be 68 inches or taller to become a fire fighter. (a) What proportion of adult men will meet this height ...

**Physics**

An Object of mass 7 kg is pushed along a surface up to a velocity of + 10 m/s before it is let go. It then slows to a stop due to an 11-N frictional force. How long until it comes to a stop?

**Physics**

A 15.0-g metal cylinder is placed on a turntable, with its center 73 cm from the turntable's center. The coefficient of static friction between the cylinder and the turntable's surface is μs = 0.79. A thin, massless string of length 73 cm connects the center of ...

**Physics**

A red colored ball tossed upward reaches a maximum height of 3.0m. show that the initial speed is 7.7m/s^2.

**Math**

$38,000 loan, 60 month/ 5years, 7.5% rate, and the payments are made quarterly not monthly. How much are the payments going to be?

**Phyics**

A cylinder which is in a horizontal position contains an unknown noble gas at 4.63 × 104 Pa and is sealed with a massless piston. The piston is slowly, isobarically moved inward 0.202 m, while 1.95 × 104 J of heat is removed from the gas. If the piston has a radius...

**Economics**

Can someone please explain the difference between these, and how they apply to someone that has monotonic preferences? I have read in the book but they all seem to be running together and am so confused! Thank you. Symmetry Convexity Local Non-satiation Transitivity Completeness

**Math Please Check**

Please check my answers! Thank you! Simplify the following expressions. Collapse “x” terms, and/or simplify fractions and exponents. 1.) (12/5) / (36/20) = 4/3 2.) x^13*x^3 = x^16 3.) x^4 / (x^2)^3 = 1/x^2 4.) x^-3 / x^2 = x^-5 5.) (x^2-8x+16) / (x-4) = x-4 6.) x^(-1...

**Microeconomics**

If the price elasticity of demand is 2, this means that a __________ increase in price causes a __________ decrease in quantity demanded. A. 15%; 100% B. 15%; 10% C. 20%; 40% D. 30%; 20% answer B 15%, 10%

**math**

Say if these numbers make a right triangle and a Pythagorean triple: 2, 2 square root 2, and 2 square root 3. I am confident that the answer for both parts of the question is no, because when 2 is squared and when 2 square root 2 is squared it is larger than 2 root 3 squared. ...

**Psychology**

Please Make Small Sounds. I like this one because it is related to language

**Calculus 2 (Series - Convergent or Divergent?)**

Can someone show me a step by step process and explanation how to solve this problem? 1) Consider the following series. (∞ on top of summation symbol) (k = 1 under the summation symbol) ∑ k(k+15)/(k+13)^2 Determine whether the series is convergent or divergent. If ...

**Calculus 2**

I need help in solving an initial-value problem and a few series problems (Especially on #45 & #46). I don't really understand how to do the series problems...majority of the time. An explanation would be great as well. Thank you for your time. #20) Solve the initial-value...

**physics**

When swimming across a river you swim to the east at 1.0 mph while the river flows southward at 2.4 mph. Your velocity is a superposition of these two velocities. What is your speed (i.e. the magnitude of your velocity)? i have no idea how to do this please help

**physics**

A box of books weighing 349 N moves with a constant velocity across the floor when it is pushed with a force of 434 N exerted downward at an angle of 37.9◦ below the horizontal. Find μk between the box and the floor.

**Accounting**

Can someone please tell me how to set this up? I tried doing (45+1.50 - 47) x 150 but I don't think this is right. thank you An investor in a Corporation. On January 1, Year One, purchased 150 shares of the corporation’s capital stock at a price of $45 per share. On ...

**math**

The perimeter of a rectangle is 72. the length of the rectangle is twice the width. Find the dimensions of the rectangle.

**math**

192 fl oz=_ pt

**math**

b

**College Algebra 1**

What is the interval notation for -4(x+9)^3(x-11)^4(x+6)>0

**Art**

thanks ^^^

**physics**

We're you able to solve this? I cant find the answer!

**Calculus**

Would you please check my answer to make sure I did it right? Bus travel, a bus company finds that monthly costs for one particular year were given by C(t) = 100 + t^2 dollars after t months. After t months the company had P(t) =1000 +t^2 passengers per month. How fast is its...

**Math**

1. Find the common ratio and the 7th term of the sequence 2/9, 2/3, 2, 6, 18, ..... 2. The 3rd and 5th terms of a geometric sequence are 2 and 1/2 respectively. What is the first term? 3. Find the geometric mean between: a. 1/2 and 1/3 b. sqrt5 - sqrt2

**Math**

Find the number of the sides of a regular polygon, if the measure of one of its exterior angle is between 28 and 32.

**Math**

If the measure of an interior angle of a regular polygon is 165, find the sum of the measures of its interior angles

**Math**

The sum of the measures of four of the angles of a heptagon is 520. Two of the remaining three angles are congruent. The other remaining angle is 3/2 the measure of one of the two congruent angles. Find the measures of the remaining angles.

**Math**

1. Victor brought a brand new car for 750,000. IF the value of the car depreciates 20% per year, what will it be worth during the fourth year? 2. Given the terms a10 = 3/512 and a15 = 3/16384 of a geometric sequence, find the exact value of the first term of the sequence.

**Calculus**

Find all values of x if any where the tangent line to the graph of the given equation is horizontal? y= x - sqrt (x) I am very confused would I work it like this? y = x - x^-1/2 then set x = 0? Please explain. thank you!

**physics**

A net force of 5.34 N acting for 4.23 s on a mass initial at rest, causes it to travel 4.75 m in a straight line. What is the mass?

**Math**

1. A 16-team bowling league has 800,000 to be awarded as prize money. If the last-placed team is awarded 12,500 in prize money and the award increases by a constant amount for each successive finishing place, how much will the first-placed team receive? 2. In Museum A, a stamp...

**Calculus**

I am so lost, I have no idea what to do next. Find the equation of the tangent line to the graph at the indicated point f(x) =x^2 +x ; a=-1 I started out using f(-1)= (-1+h)-(-1)/h but i am so lost on what to do next. I have tried to look at examples in the book, but i do not ...

**Math**

What is a1 if a33 is equal to -2p and a74 = 26p? Our topic is arithmetic series and sequence. Thanks.

**Algebra**

What is a1 if a33 is equal to -2p and a74 = 26p? Our topic is arithmetic series and sequence. Thanks.

**Reading**

Where do I put it on the poster?

**Reading**

It was more of a curse.

**Reading**

If I'm putting it down on the poster, do I write it as it is or do I write it like this: "A faerie named Maleficent decided to cast a spell on the King and Queens new-born named Aurora. She did this in revenge of King Stefan cutting off her wings." -

**Reading**

A faerie named Maleficent decided to cast a spell on the King and Queens new-born named Aurora. She did this in revenge of King Stefan cutting off her wings.

**Reading**

When Maleficent heard that Stefan cut her wings off so he could become King, she was furious.