# Posts by Jessica

Total # Posts: 3,287

**Science**

Does hot or cold water dissolve faster in with 20g of sugar

*September 28, 2015*

**Math**

The answer would be 57.1985401309. I'm not exactly sure how to explain it.

*September 27, 2015*

**Quick math help**

No, you are correct. Great job!

*September 27, 2015*

**Chemistry I - University**

Suppose 5.87 g of barium acetate is dissolved in 300. mL of a 71.0 m M aqueous solution of sodium chromate. calculate the final molarity of barium cation in the solution. You can assume the volume of the solution doesn't change when the barium acetate is dissolved in it...

*September 27, 2015*

**Chemistry I - University Level**

@ DrBob222 I know my ions are the same as my moles but I am having trouble understanding what I do next. Can you explain how you broke down this problem? What steps am I missing? Thank you!

*September 27, 2015*

**Chemistry I - University Level**

Suppose 5.87 g of barium acetate is dissolved in 300. mL of a 71.0 m M aqueous solution of sodium chromate. calculate the final molarity of barium cation in the solution. You can assume the volume of the solution doesn't change when the barium acetate is dissolved in it. ...

*September 27, 2015*

**math**

The price of a small cabin is $55,000. The bank requires a 5% down payment. The buyer is offered two mortgage options: 20-year fixed at 7.5% or 30-year fixed at 7.5%. Calculate the amount of interest paid for each option. How much does the buyer save in interest with the 20-...

*September 25, 2015*

**math**

The price of a small cabin is $35,000. The bank requires a 5% down payment. The buyer is offered two mortgage options: 20-year fixed at 7.5% or 30-year fixed at 7.5%. Calculate the amount of interest paid for each option. How much does the buyer save in interest with the 20-...

*September 25, 2015*

**Physics**

Suppose a rocket ship in deep space moves with constant acceleration equal to 9.80 m/s2, which gives the illusion of normal gravity during the flight. (a) If it starts from rest, how long will it take to acquire a speed 12% that of light, which travels at 3.0 × 108 m/s...

*September 22, 2015*

**Chemistry**

2H202-> 2H2O + O2 Suppose you carry out the decomposition using 25.0 mL of a 2.00M hydrogen peroxide solution and obtain the following: 8.62 mL of gas is collected in 120 seconds. How many moles of oxygen are produced per second?

*September 21, 2015*

**algebra**

c.750

*September 15, 2015*

**Math**

Gymnastic lessons cost $30 per week. How much will 18 weeks of gymnastic lessons cost?

*September 14, 2015*

**Economics (Net Present Value**

Hi Leo, Use formula, NPV=FV/(1+i)^n... - C. You almost had it right, but you multiplied instead of dividing. Little late than never.

*September 7, 2015*

**Chemistry**

That's the same issue i'm having. This is directly from my printed lab sheet.

*September 7, 2015*

**Chemistry**

Experiment questions: Experiment 1 results mass of beaker:116.944 g mass of dodecanoic:11.629 g hot water: 175 C warm water: 10 C Average Fressing pt of Dodecanoic = 42.7 Experiment 2 results: Unknown C solution mass: 2.091g Hot water: 175C warm water: 10C average FP of UK C ...

*September 7, 2015*

**physics**

What state of the art computer technology is used to train pilots when wanting to copy the experience of flying an aircraft?

*August 30, 2015*

**Math**

If m and n are integers, which of the following must be an even integer? A. 2mn B. mn C. mn+2 d. mn-2 e. 3mn

*August 25, 2015*

**English**

Thank you!

*August 23, 2015*

**English**

Is the sentence "Confiscation is legal." a simple sentence where "confiscation" is used as a noun?

*August 23, 2015*

**English**

How would I use the word "Salvation" as a noun in a simple sentence? My first sentence was He gave salvation, but he is the noun in that sentence. My second sentence was Salvation was given.

*August 23, 2015*

**Chemistry**

in the equation, n = cv, what is the meaning of n? I know that it stands for the number of moles, but I'm not exactly sure what that means. Our teacher wants us to mention Avogradro’s number in our explanation

*August 14, 2015*

**Calculus**

I am so appreciative of your help, but what happened to the b?

*August 6, 2015*

**Calculus**

I have the question :A small blood vessel of radius 2mm branches off at an angle(theta) from a larger blood vessel of radius 4mm. According to Poiseuille's Law the total resistance to the blood flow is proportional to T=(a-bcot(theta)/4^4)+(bcsc(theta)/2^4) Show that the ...

*August 6, 2015*

**Calculus**

My question is:Use L'Hospital's rule to find limit as x approaches 0 (e^x-e^-x-2x)/x-sinx. 1st I took the derivative to get (e^x-e^-x-2)/1+cosx. Substituting in 0, I got -1. The answer is supposed to be 2.I also tried (e^x-xe^-x-2)/1+cosx, and wound up with -(1/2). I ...

*August 6, 2015*

**Chemistry**

H2=-0.0037 I2=-0.0037 Hi=0.0276 (0.0276)^2/(0.0037)(0.0037)=56 2.00-x +2.00-x==> 2x Am I heading in the right direction?

*July 28, 2015*

**Chemistry**

Determine the concentration at equilibrium if you start with 4.65 grams of Hydrogen and 200 grams of Iodine in a 4.55 liter container. If you now add an extra 1.25M of I2 after equilibrium, calculate Qc. Recalculate now what the concentrations should be at equilibrium. H2(g...

*July 28, 2015*

**Math**

Suppose the stock of Microsoft increases in value by $5 per share. If all other Dow stock prices remain unchanged, how does this affect the DJIA? a) 37.80 points up b) 30.24 points up c) 22.68 points up

*July 27, 2015*

**Math**

Suppose the rate of inflation this year is 4.5%. What is the percentage decrease in the buying power of a dollar? a) 4.3% b) 4.7% c) None of the above.

*July 27, 2015*

**Math**

1. Suppose the buying power of the dollar decreases by 6.7% this year. What is the rate of inflation this year? a) 7.6% b) 7.2% c) None of the above.

*July 27, 2015*

**Chemistry**

The activation energy (E*) for a reaction is 195 KJ. If the k for this reaction is 3.46 x 10-5/min at 35oC, what will the temperature be in OF when k is 1.5 x 10-3/min?

*July 22, 2015*

**Chemistry**

You mix 45 ml of .20M HCl with 45 ml of .20M KOH in a calorimeter. The temperature of both reactions before mixing is 21.5oC. The temperature rises for the mixture to 22.7oC after mixing. What is the enthalpy change per mole of water produced?

*July 22, 2015*

**Chemistry**

(3.5x10^-3/5.3x10^-5)/(1/330)-1/285)=.0035

*July 21, 2015*

**Chemistry**

If the rate of the reaction is 3.5 x 10-3 at 330 K, and the rate of reaction at 285 K is 5.2 x 10-5 what is the activation energy Ea in KJ/mole?

*July 21, 2015*

**Chem**

450x2.010(110-100)=9045 8566.25+18828+9045+4183+89=40711.25 (40711.25)(114.2g/mol)= 4649334.74

*July 21, 2015*

**Chem**

2.010 Do I replace that with the 1.86

*July 21, 2015*

**Chem**

2.010

*July 21, 2015*

**Chem**

Steam : 450x1.86(110-100)=8370 8566.25+18828+8370+4183+89=40036.25kj (40036.25)(114.2g/mol)= 4572139

*July 21, 2015*

**Chem**

450x4.184(100)188280 450x4.184(110-100)= 18828 18828+4183=23011 23011g of gasoline

*July 21, 2015*

**Chem**

Cu specific heat: 0.385 H2o specific heat: 4.184 21+273.15=294.15 110+273.15=383.15 {I subtracted these and got} ______ 89 250x0.385(383.15-294.15)= 8566.25 450x4.184(383.15-294.15)= 167569.2 47(110-21)=4183 I'm lost on this problem

*July 21, 2015*

**Chem**

It's Jessica from my first screen name On this problem I wanted to know if I'm going with the correct formula q= CpxmassxTf-Ti 250 g being mass I just do t know how to set up the formula

*July 21, 2015*

**Chem**

When a piece of Copper weighing 250 grams is placed in a cup with 450 ml of water at 21OC and the Cp of the cup is 47 J/K, how many grams of gasoline would it take to heat the system to 110OC?

*July 21, 2015*

**Chemistry II**

CpxmassxTf-Ti (2.06)(275)(0-(-25))=14162.5 333J/100x14162.5 = 47161.125 47161.125+14162.5= 61323.625 61323.625(1gas/48,000)= answer: 1.277g of steam Thank you to the way for helping chemistry isn't my best subject so I apreciate the time y'all put in to help tutor

*July 21, 2015*

**Chemistry**

T1= 27+273.15=300.15K T2=90+273.15=363.15 K In(1/300.15)-(2/363.15)= 5.709???? Did I get it?

*July 21, 2015*

**Chem**

K=0.693/24 = .028875 In(.100/.33)/-.028875= 41.34 sec

*July 21, 2015*

**Chem**

-0.693/ In(.100/.33) = 17.23 seconds I know I did my math off but I'm not sure if I did it correct this time would it be 17.23 sec

*July 21, 2015*

**Chem**

0.693/In(.100/.33)= -.5804

*July 21, 2015*

**Chem**

If compound X has a first-order half-life of 24 seconds, how long would you have to wait for only 33% of the original material to be left? Explain why not knowing original Molarity of X does not effect this problem.

*July 21, 2015*

**francais (french)**

I just need to know if im right or not, and the right answers.. about the accents i know them i just cant type them here.

*July 20, 2015*

**francais (french)**

And about the "pour" and "de" this is how the sentence was given by my teacher.. so i cant change them i don't think..

*July 20, 2015*

**francais (french)**

My answers 1. desquelles 2. auquel 3. desquels 4. auxquelles 5. a laquelle

*July 20, 2015*

**francais (french)**

Remplissez les tirets avec la bonne forme de "lequel" If my answers are correct 1. Margo revait de sa soeur pour___ il avait de l'admiration 2. Voila une solution_____ je n'ai jamais pense(a) 3. Tout le monde admirait celle fille ______ on citait des poemes ...

*July 20, 2015*

**media**

Can the source language of the film have an impact on its diffusion and its distribution?

*July 17, 2015*

**Calculus**

My question is finding the derivitive of y=((x+λ)^4)/(x^4+λ^4). I distributed the exponent in the numerator, but I don't know if that's right. Rewritten as y=(x^4+λ^4)/(x^4+λ^4). I found the derivitive and multiplied accordingly, as ((4x^3+4λ^3...

*July 15, 2015*

**Calculus**

So, I have a homework question on The Quotient Rule (taking derivitives) and I would like to know if I did it right. Calculate: y=(1/sqrt(x))-(1/(5th root of x^3). My 1st step was to change the sqrt to x^1/2, and the 5th root to x^1/5+^3. So then I got y=(1/x^1/2)-(1/x^16/5). ...

*July 15, 2015*

**College Algebra**

Marcus bought y movie posters for $3 each. Write an algebraic expression for total amount Marcus spent

*July 13, 2015*

**Language**

Click on the line with an error. We have already eaten lunch. Just between you and I, what did you think about the food? No error

*July 11, 2015*

**physics**

A 0.700 kg object is swung in a circular path and in a vertical plane on a 0.550 m length string. If the angular velocity at the bottom is 12.00 rad/s, what is the tension in the string when the object is at the bottom of the circle?

*July 7, 2015*

**Algebra**

A total of 598 tickets were sold for the school play. They were either adult tickets or student tickets. There were 52 fewer student tickets sold than adult tickets. How many adult tickets were sold?

*July 6, 2015*

**Chem 105**

A gas has a volume of 36.0 L and a pressure of 750. torr when the temperature is 10. °C. What is the pressure if the volume changes to 15.0 L and the temperature changes to 78 °C, if the amount of gas stays the same?

*July 1, 2015*

**Psychology**

When researchers find similarities in development between very different cultures, what implications might such findings have for the nature-nurture issue?

*June 30, 2015*

**Physics**

A motorcyclist who is moving along an x-axis has an acceleration given by a=(6.60-2.29t) for 0 >= t <= 6.0 s, where a is in m/s2 and t is in seconds. At t = 0, the velocity and position of the cyclist are 3.20 m/s and 7.30 m. For the time interval from 0 >= t <= 6....

*June 29, 2015*

**english**

its about big ben

*June 23, 2015*

**english**

I need a sentence that will finish my descriptive writing off with a funny personification? Aiming for level 7.

*June 23, 2015*

**Math**

Solve for x. Express the answer in simplest form. 1/7 = 3 over 4x - 1 1/7 is a fraction

*June 6, 2015*

**Algebra**

The height of a triangle is 4 in. greater than twice its base. The area of the triangle is no more than 168 in.2. Which inequality can be used to find the possible lengths, x, of the base of the triangle

*June 6, 2015*

**Math**

A spinner has three sections. The table shows the results of spinning the arrow on the spinner 80 times. Section 1 18 Section 2 30 Section 3 32 What is the experimental probability of the arrow stopping over Section 3? A. 1/3 B. 1/32 C. 3/32 D. 2/5

*June 6, 2015*

**Chemistry**

The density of pure diamond is 3.5 g/cm^3. The mass of a diamond is 0.25 g.Calculate its volume.

*June 2, 2015*

**informal logic**

Mrs. Orlof teaches two history classes, one in the morning and one in the afternoon. Yesterday she gave the same test to both classes. Anyone who failed the test must take a retest. Since a greater percentage of students who took the morning test failed the test than students ...

*June 2, 2015*

**math**

use inductive reasoning to determine the units digit of the number 2^44 the unit digit of 2^44 is_____ powers of 2- 2^1=2 2^2=4 2^3=8 2^4=16 and so on that last one they have is 2^12 so 2^44 would be 1.7592188?

*June 2, 2015*

**math**

Joanie wants to mail a package that requires $1.30 in postage. If she has only 5-cent and 7-cent stamps, what is the smallest number of stamps she could use that would be totally exactly $1.30? the smallest number of stamps is ____.

*June 2, 2015*

**Math**

a turtle is at the bottom of a 11 foot well. each day it crawls up 5 feet, but each night it slips back 3 feet. after how many days will the turtle reach the top of the well? the turtle will reach the top of the well after ___ days THANK YOU

*June 2, 2015*

**english**

Thank you

*May 24, 2015*

**english**

She attributed his shallowness to his luxurious upbringing, in which material comforts like fine clothes and large homes nurtured his sense of privilege. Which of the following is the meaning of "material" as used in the sentence above? A. The substance from which ...

*May 24, 2015*

**english**

The store will stay open later during the holiday season. The store will stock a variety of seasonal merchandise. The store will have many discounts available for holiday shoppers. 22. When revising the paragraph above, the writer should address which of the following? A. ...

*May 24, 2015*

**Chemistry**

At the start of the process 118 kg of isobutylbenzene is used and the overall yield of the 3 reaction steps is 24%, how many 400 mg tablets of ibuprofen will be produced? Isobutylbenzene: Chemical formula = C10H14 Molecular Weight = 134.22g 2-(4-isobuytlphenyl) propanoic acid ...

*May 20, 2015*

**Chemistry**

Choccamine and mintanol have Rf values of 0.81 and 0.21 respectively. What would the distance in centimetres (cm) between the two compounds be if the TLC was run on a TLC plate where the solvent front moved 8.9 cm from the baseline?

*May 20, 2015*

**History**

Who did Lincoln command as the first "General of the Union army"

*May 18, 2015*

**math for college readiness**

Suppose y varies directly with x. Write an equation relating x and y. y = −30 when x = 6

*May 17, 2015*

**English**

Would knowledge be considered a theme in Anthem by Ayn Rand?

*May 10, 2015*

**Chemistry**

Yes I got 0.996% and rounded. Thanks very much for your help!

*May 10, 2015*

**Chemistry**

I understand what you are talking about now because I did not factor in the 94mL. I have added this step in and now got 1.00%

*May 10, 2015*

**Chemistry**

I thought I already had moles though? Which was 0.017 Mol?

*May 10, 2015*

**Chemistry**

Okay so this is my process: Mass of Vanillin (C8H8O3) = molar mass x moles 152.15 x 0.017 = 2.59g Mass of Vanillin = 2.59g Mass of Vanilla pods = 24.41g % of vanillin in vanilla pods: (2.59 / 24.41g) x 100 = 10.61% Does this sound right?

*May 10, 2015*

**Chemistry**

A 94 mL vanillin solution with a concentration of 0.017 mol L-1 was made by extraction from 24.41 g of vanilla pods. Calculate the percentage of vanillin in the vanilla pods. It would be helpful if you could explain to me the process to work out this question instead of just ...

*May 10, 2015*

**English**

We had a chart from A-Z for Anthem by Ayn Rand. For each letter much be at least rhetorical device or a mood or tone. I need help with letters K, Q, W, V, X, Y, Z

*May 10, 2015*

**math**

Which answer was correct?

*May 4, 2015*

**Chemistry**

Consider the reaction: M + 2HCl ¨ MCl2 + H2 When 0.85 mol of the metal, M, reacted with an aqueous HCl solution (the HCl is in excess), the temperature of the solution rose because the reaction produced 6795 J of heat. What is ∆H in kJ per mol of M for this ...

*May 4, 2015*

**English**

What are some analogies in Anthem by Ayn Rand from chapters 9-12

*May 2, 2015*

**Pre-Calculus**

At 34 degrees north latitude, the longest day of the year has 14.273 hours of daylight, and the shortest day 9.726 hours. If the equinox falls on march 21(day 80), model the hours of the daylight by day?

*April 28, 2015*

**Algebra**

1.0<x<1. Which must be true? I. x^9 < x^7 II.x^7+x^5 < x^6+x^4 III. x^7-x^5 < x^6-x^4 2. A football team average x points (the mean) in the first n games, scored y points in the next game, and z points in the one after that . The mean of the n+2 is A.(x+y+z) / (...

*April 28, 2015*

**linear**

Suppose that we have a system consisting of two interconnected tanks, each containing a brine solution. Tank A contains x(t) pounds of salt in 200 gallons of brine, and tank B contains y(t) pounds of salt in 300 gallons of brine. The mixture in each tank is kept uniform by ...

*April 28, 2015*

**Hallandale high**

^ excuse me bob?!

*April 28, 2015*

**Chemistry**

4.18

*April 21, 2015*

**Chemistry**

Determine the pH of a solution of 12.00 mL of 0.2 M acetic acid with 10 mL of a 0.025M NaOH? (Ka = 1.8E–5) I've calculated my excess moles of acetic to be .00215. Total volume being .022L. Where do I go from here? Thanks!

*April 21, 2015*

**4th Math**

Sam cut the pic into 6 sides

*April 20, 2015*

**math**

Use Part 1 of the Fundamental Theorem of Calculus to find the derivative of the function. g(x) = e^(3t^2) − 3t dt from 4 to x

*April 20, 2015*

**Physics**

i usually go with B if I don't know

*April 18, 2015*

**Chemistry**

Okay so in our class we did an ice cream lab where we use Ziploc bags to make ice cream. We made an ice cream mixture and then put it into a smaller Ziploc bag. Then we got a large Ziploc bag and placed ice in it and placed the bag with the ice cream mixture into the large bag...

*April 17, 2015*

**Chemistry**

If 0.605 g of magnesium hydroxide reacts with 1.00g of sulfuric acid, what is the mass of magnesium sulfate produced? Mg(OH)2(s)+H2SO4(l)→MgSO4(s)+H2O(l) .605g Mg x 1molMgSO/1molMg=.605g MgSo 1.00g MgSO/1mol H2SO4=1.00g MgSO .605g+1.00g=1.605g This is incorrect, but I ...

*April 17, 2015*