Tuesday

July 7, 2015

July 7, 2015

Total # Posts: 1,765

**Organic Chemistry**

Dr. Bob, Thank you for the chart; its really helps. Just to make sure I am on the same page as you. I look up the bonds listed. F-I has the highest deltaHf (kj/mol). So that means that is takes more energy to break that bond; thus have the strong bond?
*June 22, 2015*

**Organic Chemistry**

1. Which of the following bonds is the strongest? a. F-F b. F-Cl c. F-Br d. F-I I think it's A because of the same atomic radius. Is that correct? Am I on the right track?
*June 22, 2015*

**geometry**

An artist wants to make alabaster pyramids using a block of alabaster with a volume of 576 cubic inches. She plans to make each pyramid with a square base area of 3 square inches and a height of 4 inches. At most, how many pyramids can the artist make from the block of ...
*June 19, 2015*

**Chemisrty**

Calculate the grams of substance from the moles of substance given.... 2 moles C6H10O5. Please help I am lost!
*June 17, 2015*

**Organic Chemistry**

Which isomer of 1-ethyl-3-methylcyclohexane is more stable, cis or trans? My teacher hasn't covered this material as of yet, but we have a test done tomorrow on it. What is a cis and trans? Not sure how to begin figuring this out. My text book isn't helpful. Thanks
*June 15, 2015*

**Organic Chemistry**

Thank you Dr.Bob. For some reason my textbook doesn't have any answers to the selected problems so I don't know if I on the right track. I really appreciate your help.
*June 14, 2015*

**Organic Chemistry**

What is the hybridization of all the atoms (other than hydrogen) in each of the following species? a) NH3 e) +NH4 i) H3O+ b) BH3 f) +CH3 j)H2C=O c) -CH3 g) HCN d)*CH3 h) C(CH3)4 There are a couple I don't know how to do. Please help? Did I do the other correctly? Thanks. a...
*June 14, 2015*

**Organic Chemistry**

Is eutectic point and eutectic mixture the same thing? If not what is the difference between the two? Thanks in advance.
*June 11, 2015*

**us gov**

what single word means the same thing as representative democracy
*June 10, 2015*

**Chemistry**

analyze and describe the different types of genetic mutations and their effects
*June 8, 2015*

**Math**

Q. Tim and Jorge hope they will be assigned to the same cabin at the summer camp. Each cabin has 8 beds in it. And Tim knows that he is saying in the green cabin not the red cabin. If there are 14 boys going to camp in addition to Tim and Jorge. What is the change that Tim and...
*May 28, 2015*

**Math**

Thanks!
*May 21, 2015*

**Math**

Thanks!
*May 21, 2015*

**Math**

Q. Neil found out that the Sunday paper that he delivers is about 1 pound and 12 ounces. He delivers 39 newspapers on Sunday's. How much do the 39 newspapers weigh? (Hint: 16 ounces = 1 pound) A. I tried adding 16 12 times but that didn't work after I found out it was ...
*May 21, 2015*

**Math**

4:31
*May 19, 2015*

**Math**

Q. Juan delivers papers every morning before he goes to school. He has to have all the papers delivered by 6:30 am. He has 86 papers and he figures it takes him an average of one and one half minutes to deliver each paper. At what time must he start in order to be done as ...
*May 19, 2015*

**Chemistry**

A 10.0mL sample of H2SO4 was neutralized by 13.5mL of 1.0M KOH. What was its molarity of H2SO4? What is the normality?
*May 18, 2015*

**Math**

Thank you
*May 14, 2015*

**Math**

292-223=69
*May 14, 2015*

**Math**

Q. Mrs.Ramirez's class was getting ready to plant tomatoes. They we're wondering if each package of tomato seeds contained the same number of seeds. They counted the seeds in four packages and found that there was a average of 73 seeds in the package. The first three ...
*May 14, 2015*

**Townview**

Elaine is painting a fence. She knows that she needs 1 gallon of paint for each 10 feet of fencing. The fencing will enclose a rectangular yard that is 3 yards long and 2 yards wide. How much paint does Elaine need? (Remember 3 feet = 1 yard)
*May 14, 2015*

**Chemisty**

Dr. Bob, Where are you getting the 0.693 from?
*May 14, 2015*

**Chemisty**

The activity of a radioisotope is 3000 counts per minute at one time and 2736 counts per minute 48 hours later. What is the half-life of the radioisotope?? a) 831hr b)521hr c)361 hr d)1.44hr
*May 14, 2015*

**Math**

Q. Mr. Kincaid's class wants to plant 1/4 (fraction) of its 12-foot-square plot with tomatoes. Of the remaining garden, 1/3 will be pears. Of the rest of the plot,1/2 will be radishes, and 1/2 will be lettuce. How many square feet of radishes will the class plant.?
*May 13, 2015*

**Bio 20**

Hydrogen sulfide gas is combusted with oxygen gas to produce sulfur dioxide gas and water vapour. If there is 19.3 L of oxygen gas, what maximum volume of hydrogen sulfide gas could be combusted?
*May 11, 2015*

**Chemistry 20 **

Hydrogen cyanide gas is produced industrially by the reaction 2 CH4(g) + 3 O2(g) + 2 NH3(g) → 2 HCN(g) + 6 H2O(g) What volume of O2(g) is needed to completely react 17 L of CH4(g) at STP?
*May 11, 2015*

**Chemisty**

What is the molar solubility of AgCl, Ksp= 1.60x^-10, in a solution that also contains 0.0250 M KCl? The answer is 1.60x^-10. But I am not sure why this is. Does it have to do with the solubility rules? Please Help.
*May 7, 2015*

**Medical science**

Dimethyl ether = predominate weak dipole-dipole intermolecular force. (positively charged hydrogen atoms and the negatively charged oxygen atoms). H+ H+ H+- C- O - C - H+ H+ H+ Ethanol = hydrogen bonding (Hydrogen bonding to oxygen) H+ H+ H+ - C - C - O - H+ H+ H+ Hydrogen ...
*April 29, 2015*

**Medical science**

Dimethyl ether = predominate weak dipole-dipole intermolecular force. (positively charged hydrogen atoms and the negatively charged oxygen atoms). Ethanol = hydrogen bonding (Hydrogen bonding to oxygen) Hydrogen bonds have higher boiling points
*April 29, 2015*

**chem**

a solution is prepared with 3.26g kcl and water to make 25.0ml,of kcl,what is the %(m/V) of the kcl solution.
*April 22, 2015*

**Molarity question**

ahh thank you!
*April 18, 2015*

**Molarity question**

okay so in lab we made up 2 solutions of FeCl3 and KI. We varied the volumes...I was just wondering how to calculate a new concentration for those solutions. We weighed out .825g of the FeCl3 and 1.35 g of the KI. For trial one we used 20 mL of both. For trial 2 we used 20.0 ...
*April 18, 2015*

**Chemistry: Potentiometric Anyalysis**

Ok. Thank you. That is what I was thinking. I really appreciate your help.
*April 14, 2015*

**Chemistry: Potentiometric Anyalysis**

I am still working on a handful of the calculations.
*April 14, 2015*

**Chemistry: Potentiometric Anyalysis**

DrBob222, In the lab we used a NaOH solution with a 0.1088M to calculate the equivalence point of a unknown weak acid using "Logger Pro" program. I used 0.4530g of the unknown acid and dissolved it in 75ml of distilled water. For my 3 three trials, I gather enough ...
*April 14, 2015*

**Chemistry: Potentiometric Anyalysis**

If the pH probe was miscalibrated and reports the pH to be 1 unit higher than the true pH of the solution it is in, would the molar mass you report for the solid acid be higher, lower, or equal to the true molar mass of the acid? This for my post lab write up. I think that the...
*April 14, 2015*

**Math**

Perform the calculations 6 ft, 5 in,-2 ft, 7 in = what in ft, and inches Thanks
*April 14, 2015*

**Math**

Perform the following calculations 7 yds , 1ft -3 yds, 2 ft= what in ft Thanks
*April 14, 2015*

**Math**

A plane has a height of 1000 m. You see the plane at an angle of 40 degrees with the ground . How far away is the plane from where you are standing.
*April 12, 2015*

**Math**

A wall has dimensions 25 m by 10 m represent the wall with a drawing if the scale is 1 cm represents 5 m
*April 12, 2015*

**Chemistry**

0.688g of antacid was treated with 50.00ml of 0.200M HCl. The excess acid required 4.21 mL of 1.200 M NaOH for back-titration. What is the neutralizing power of this antacid expressed as mmol of HCl per gram of antacid? I think the answer should be: (50.00ml HCl)(0.200M HCl)= ...
*April 6, 2015*

**physics**

A car speeds up uniformly from rest so that it has a velocity of 30ms -1 after 20 second.How far does the car travel in first 10 seconds?
*April 6, 2015*

**physics**

A car speeds up uniformly from rest so that it has velocity of 30 ms-1 after 20 seconds. Question/ How far does the car travel in first 10 seconds?
*April 6, 2015*

**physics**

A car speeds up uniformly from rest so that it has a velocity of 30 ms-1 after 20 second. How far does the car travel in first 10 second?
*April 6, 2015*

**Chemistry**

The bubble in the tip of the buret is not removed prior to performing the NaOH standardization. Will the reported concentration of the NaOH be greater than, less than, or equal to the true concentration of the NaOH if the bubble is flushed from the buret during the titration? ...
*April 4, 2015*

**Chemistry**

am I doing this equation correctly, please help. K3PO4(aq) + Ba(NO3)2(aq) my answer: 3K(NO3)2(aq) + 2Ba(PO4)3(s) Double displacement precipitation
*April 4, 2015*

**Chemistry**

Why can't milk of magnesia (Mg(OH)2), act as a buffer?
*April 2, 2015*

**Chemistry**

A jar contains 75mL of a .45M silver nitrate solution. Will 200g of solid copper be enough to bring all the silver out of solution as a solid?
*March 30, 2015*

**Chemistry**

Thank you Dr. Bob222
*March 30, 2015*

**Chemistry **

Given that Ka for HIO is 3.2 × 10-11 at 25 °C, what is the value of Kb for IO– at 25 °C? Then, Given that Kb for C6H5NH2 is 1.7 × 10-9 at 25 °C, what is the value of Ka for C6H5NH3 at 25 °C? I don't know where to start? Do I need an ICE ...
*March 30, 2015*

**Physical Science**

A man loads 1,000 sacks of flour into a truck in 30 minutes. each sack has a mass of 20 kg and the man must lift each sack 1.00 m from a cart up onto the truck bed. How much power did the man develop?
*March 30, 2015*

**Physics**

A motorist is trying to loosen a stubborn lugnut by standing on the end of a wrench. The wrench is inclined 33.8 degrees above the horizontal and the distance from the center of the nut to the end of the wrench is 0.60 m. Assuming the motorist does not bounce up and down on ...
*March 29, 2015*

**Chemistry**

Great! Thank you. This helps a lot!
*March 27, 2015*

**Chemistry**

A buret is partially filled with NaOH solution, to a volume of 1.14mL. A 20-mL sample of 0.1011 M HCl is titrated to a faint pink phenolphthalein endpoint. The final buret buret reading is 22.37mL. What is the molarity of the NaOH solution? Please help. Thank you in advance.
*March 27, 2015*

**Math/Science**

How do you convert millimeters to micrometers? For 10 mm, I got .010 micrometers, but I'm not sure if that's right.
*March 25, 2015*

**algebra**

what is the square root of 144?
*March 23, 2015*

**English**

Is the foghorn an archetype then ? I'm just really lost in this whole poem. Because archetypes are suppressed in the unconscious, so they talk about something they never intended is that what is meant ?
*March 19, 2015*

**English**

That is the idea that was proposed...I just don't understand the poem and its context in order to apply Jung's theory.
*March 19, 2015*

**English**

There is a deeper meaning to the poem and I am supposed to analyze the poem using Jung's theory of the psyche !
*March 19, 2015*

**English**

I need help with the following poem analysis, I do not know what it is saying! FOGHORN Surely that moan is not the thing That men thought they were making, when they Put it there, for their own necessities That throat does not call to anything human But to something men had ...
*March 19, 2015*

**math**

An arc AB of length 5cm is marked an a circle of radius 3cm. Find the area of the sector bounded by this arc and the radii from A and B.
*March 15, 2015*

**math**

A cord AB of length 4cm divides a circle of radius 3.3cm into two segments.find the area of each segment.
*March 15, 2015*

**math**

which pizza has the best value for the money; a 10 inch round pie for $6 or a 14 inch pie for $10? Support your answer.
*March 14, 2015*

**math**

6/(v-5)(v+2) if the rational expression is defined for all real numbers
*March 9, 2015*

**math**

Leslie needs 324 inches of fringe to put around the edge of a tablecloth. The fringe comes in lengths of 10 yards. If Leslie buys 1 package of fringe, how many feet of fringe will she have left over?
*March 9, 2015*

**Math**

A phone tree is used to let committee members know that a meeting is cancelled. The committee chair calls 5 people . Those 5 people each call 5 people and those additional people each call 5 people. How many members have been called?
*March 6, 2015*

**CHEMISTRY!!!!**

Determine the pH at the equivalence point in the titration of 41.0 mL 0.096 M formic acid with 0.108 M NaOH at 25oC. Calculate the pH of a solution that is 0.22 M pyridinium ion (C5H5NH+) at 25oC.
*March 5, 2015*

**Chemistry! Please Help!**

I have part b if that helps 100 g of CacO3 give 44 g of CO2 so 12 g will give 5.28 g of CO2 so moles of CO2 = 0.12 moles Volume = 0.12 X 22.4 L = 2.688 L PV = nRT Pressure = 0.12 X 0.0821 X 998 / 2.688 = 3.65 atm
*February 26, 2015*

**Chemistry! Please Help!**

Lime (CaO) is used to prevent SO2 from escaping smokestacks of coal burning power plants by the formation of solid CaSO4•2H2O also known as the mineral gypsum. One of the important reactions in the overall process is the dissociation of CaCO3(s). b. If a 12.0 g sample of ...
*February 26, 2015*

**Math**

The math question is "in a piggy bank there is a total of $15.75. If the ratio of dimes to quarters is 5:7, find the total amount in quarters. My question is, what formula would I use to solve this?
*February 19, 2015*

**Chemistry!!!!**

1. For a reaction mechanism to be plausible, what 2 criteria must be met? 2. The reaction between CO and NO2 to produce NO and CO2 is thought to occur in 2 steps. NO2 + NO2 ====> NO + NO3 NO3 + CO =====> NO2 + CO2 The experimental rate law is, R=k[NO2]2 Write the ...
*February 12, 2015*

**Chemistry!!!!**

1. For a reaction mechanism to be plausible, what 2 criteria must be met? 2. The reaction between CO and NO2 to produce NO and CO2 is thought to occur in 2 steps. NO2 + NO2 ====> NO + NO3 NO3 + CO =====> NO2 + CO2 The experimental rate law is, R=k[NO2]2 Write the ...
*February 12, 2015*

**physics**

A man named Harold is standing in a train car that has no windows. Since there aren't any windows, he doesn't know how fast or in what direction the train is moving or whether it is accelerating or decelerating. Harold decides that he might be able to figure something ...
*February 11, 2015*

** chemistry**

Balance redox reaction. Fe(s) + O2(g) + H2O(l)-->Fe2+(aq) +OH-
*February 8, 2015*

**Physical science**

A 70-kg man and a 50-kg woman are in a 60-kg boat when its’ motor fails. The man dives into the water with a horizontal speed of 3 m/s in order to swim ashore. If he changes his mind, can he swim back to the boat if his swimming speed is 1 m/s? If not, can the woman ...
*February 6, 2015*

**Chemistry**

1. If an aqueous solution that is 0.15 M in HF has an osmotic pressure of 3.9 atm at 25oC, what is the percent ionization of HF at this concentration? 2. A mixture of 2 volatile liquids is said to be ideal if each component obeys Raoult’s Law: Pi=XiPio Two volatile ...
*February 4, 2015*

**biochemistry**

Calculate the pH of the solutions obtained by dissolving the following in a liter of water: 0.2 mole of glycine plus 0.1 mole of NaOH I know the answer is ph = 9.60 which i know is pka2 of glycine but im not sure how to set up this question. This is just a practice problem for...
*January 30, 2015*

**English (Dracula)**

ok thank you!!! i like night stalker
*January 20, 2015*

**English (Dracula)**

I am making a Wanted Poster of Dracula and i dont know what statement to put about him below the picture of him. i was thinking like: Evil Count and Blood Thristy
*January 20, 2015*

**Dracula novel**

What are some physical and psychological attributes of Dracula
*January 20, 2015*

**Calc Physics**

The velocity as a function of time for an asteroid in the asteroid belt is given by v(t)= vo e^(-t/to)i + (vo t/ 2 to) j with vo and to constants. Use ti = 0 as the initial time, and tf = 472 s as the final time. The values for the constants that you will use are: vo = 9 m/s ...
*January 17, 2015*

**math**

Problem: A ball is dropped from the top of a building that is 250 feet tall. The height h of the ball in feet after t seconds is modeled by the function h = -16t2 +250. How long will it take for the ball to reach the ground? Round your answer to the nearest tenth if necessary.
*January 13, 2015*

**chemistry**

Sulfuric acid is dripped onto samples of three metals: silver, =zinc, and aluminium a) Use the activity series to determine whether a reaction will occur with each metal b) Write a chemical equation for each reaction that occurs
*January 11, 2015*

**algabra**

Janie's couch is 7 1/2 feet long.the scale of the dollhouse is 1 inch:2feet. what is the length of the miniature couch for the dollhouse?
*January 10, 2015*

**chemistry **

a 2.00l buffer contains 1.00 mol HNO3 mixed with 1.00mol NaNO2 a. write the relevant ionization equation for this buffer. b. determine its pH c. determine the new pH if 1.00g of NaOH is added to the buffer
*January 1, 2015*

**Math**

rick has a box of coins. The box contains 51 coins. Which consist of pennies, dimes and quarters. The number of pennies equal the number of dimes the total value of the box of coins is 5.73. How many dimes? how many pennies ? how many quarters?
*December 19, 2014*

**math**

A company will need 55,000 for a new addition. To meet this goal the company deposits money in an account today that pays 5% interest annual compound quarterly. to meet this goal in five years what would the company need to deposit today?
*December 18, 2014*

**Math**

given the function f decribed by f(x)=-x-6, find f(-7)=?
*December 16, 2014*

**ap physics**

a 37.4-kg traffic light is supported by two wires prove you answer applying newtons law
*December 4, 2014*

**Chem 130**

Carbon monoxide burns in oxygen to form carbon dioxide. what volume of oxygen at 25 degrees Celsius and 760. mmHg is required to react with 15.0 L of carbon monoxide which id at STP?
*December 1, 2014*

**Algebra 2**

Solving Quadratic Systems x^2+y^2=2 x^2-6y=10 I'm having trouble solving this problem.
*December 1, 2014*

**math**

a company will need $30.000 in 7 years for a new addition. To meat this goal the company deposits money in an account today that pays 7% annual interest compounded quarterly. find the amount that should be invested to total $30.000 in 7 years?
*November 28, 2014*

**IT**

The No Interest Credit Company provides zero-interest loans to customers. Design an application that gets customer account data, including an account number, customer name, and balance due. Output the account number and name, then output the customer's projected balance ...
*November 27, 2014*

**math!!**

5^6 * 5^3
*November 26, 2014*

**math**

can you explain more im lost . plz
*November 26, 2014*

**math**

conver the numeral to a numeral in base 10 1101 basetwo can some one plz help .
*November 26, 2014*

**math**

(-q^2 +3)(q^2 -2)mulitply
*November 21, 2014*

**math**

multiply (-5-p)(5+p)
*November 21, 2014*

**Math**

multiply -p(p+q+2)
*November 21, 2014*

**Physics**

A naked person (e=0.75) with a surface area 2.00 square meters and a skin temperature of 34 degrees Celsius is in sauna at 90 degrees Celsius. If he stays in the sauna for 30 minutes, (a) How much heat does the perspn radiates? (b) How much heat does he absorb from the walls ...
*November 19, 2014*