Monday
May 25, 2015

Posts by jennie


Total # Posts: 124

Chemistry
I need help on my chem lab... I need to give you background info so you know how to help me.. Data Sheet: Specific gravity of distilled water Temp of distilled water = 20 C Specific gravity: 1.0000 or 1.000 (according to hydrometer used) sugar solution 1 : mass 18.01 g volume ...
April 30, 2015

Chemistry Dr. Bob
I need help on my chem lab... I need to give you background info so you know how to help me.. Data Sheet: Specific gravity of distilled water Temp of distilled water = 20 C Specific gravity: 1.0000 or 1.000 (according to hydrometer used) sugar solution 1 : mass 18.01 g volume ...
April 30, 2015

Chemistry
I need help on my chem lab... I need to give you background info so you know how to help me.. Data Sheet: Specific gravity of distilled water Temp of distilled water = 20 C Specific gravity: 1.0000 or 1.000 (according to hydrometer used) sugar solution 1 : mass 18.01 g volume ...
April 30, 2015

Economics
Is a country with a trade surplus better off or worse off than a country with a trade deficit? Provide your rationale.
March 17, 2015

Chemistry
Calculate the concentration of OH− and the pH value of an aqueous solution in which [H3O+ ] is 0.014 M at 25°C. Is this solution acidic, basic or neutral?
March 12, 2015

Chemistry Dr. Bob222
For Cup C Mass of cup,water,stirrer: 55.15 Mass of sodium bicarbonate: 2.02g mass of citric acid: 0.77g total mass: 57.94g mass of cup,solution, stirrer after reaction: 57.64 difference (CO2): 0.30g Calculate the theoretical yield of carbon dioxide in the plastic cup C. ** u ...
March 4, 2015

Chemistry Dr. Bob222
Ok, For Cup C Mass of cup,water,stirrer: 55.15 Mass of sodium bicarbonate: 2.02g mass of citric acid: 0.77g total mass: 57.94g mass of cup,solution, stirrer after reaction: 57.64 difference (CO2): 0.30g Part B: Limiting Reactants Plastic Cup C 7. Determine which reactant is ...
March 4, 2015

Chemistry Dr. Bob222
Ok, UMMMM I thought I was good.. Till now.. Ok, For Cup C Mass of cup,water,stirrer: 55.15 Mass of sodium bicarbonate: 2.02g mass of citric acid: 0.77g total mass: 57.94g mass of cup,solution, stirrer after reaction: 57.64 difference (CO2): 0.30g Part B: Limiting Reactants ...
March 3, 2015

Chemistry Dr. Bob
Thanks!!!! I'm learning!!
March 3, 2015

Chemistry Dr. Bob
Plastic Cup B Mass of cup, water and stirrer: 53.75g mass of sodium bicarbonate: 2.02g mass of citric acid: 1.52g total mass of all: 57.29g mass of cup, solution, stirrer after reaction: 56.59g difference (CO2): 0.70 g Now, Here's the problems it's basically just like ...
March 3, 2015

Chemistry Dr. Bob
Great! Thanks again! I got it now! I can finish the rest of my lab from these questions... I have 4 cups to do ! lol
March 3, 2015

Chemistry Dr. Bob
This is in response to the fact that my experiment had me come up with my own.. I was supposed to measure out as close to 1g as possible of sodium bicarbonate as possible.. This is my lab procedures: Plastic Cup A 1. Measure out 50 mL of distilled water with a 100-mL graduated...
March 3, 2015

Chemistry Dr. Bob
Now, I'm going to post how to figure out the theoretical yield of carbon dioxide from 1.00g sodium bicarbonate... The reaction of citric acid and sodium bicarbonate is written as H3C6H5O7(aq) + 3 NaHCO3(aq) → Na3C6H5O7(aq) + 3 H2O(l) + 3 CO2(g) Um.. I think it's ...
March 3, 2015

Chem Dr. Bob Plz
Dr. Bob, I just found an old post of someone asking this question, and I figured it out.. 1 mole citric acid reacts with 3 moles sodium bicarbonate, molar mass of NaHCO3 = 84.0 g/mol 1 mole in 1.00 g = 1.00/84.0 = 0.0119 mole sodium bicarbonate this will react with 0.0119/3 = ...
March 3, 2015

Chem Dr. Bob Plz
Dr. Bob, I just did a home lab with citric acid and sodium bicarbonate and had to put them in cups and measure before and after.. I put 1.02g of sodium bicarbonate in a cup with water and stirrer (54.66g) then added .77g of citric acid and supposed to add up total mass (56.45g...
March 3, 2015

Chemistry Help
I have no idea where to begin with this?? This class is moving so fast! Dr. Bob222 I made a 100 on my prelab!! and the online test was so fast I was going through my notes and I was scrambling to figure it out and look up stuff on the periodic table and all!! But I made an 80...
March 3, 2015

Chemistry Help
WHAT???? which of these are electrolytes?? CH3CH2OCH2OH PCl3 Na2CO3 O2
March 3, 2015

Chemistry help!! Fast
true or false??? The larger molecules dissolve best in a solvent with a low molecular weight.
March 3, 2015

Chemistry
Calculate the mass/volume percent of a NaCl solution in which 182g of NaCl is dissolved in enough water to give a total volume of 4.78L . Would I do 182/4780ml *100?
March 3, 2015

Chemistry
Ok, I figured it out... First one is 355 * 5.5% = 19.5 g then, 18.5% *2.49 L *1000 (to make mL) = 461 mL then, 42.4/6% = 707 mL Now I've figured those out on my own... I'm stuck on next problem..
March 3, 2015

Chemistry
How many grams (of mass m) of glucose are in 355mL of a 5.50% (m/v) glucose solution? You have a solution that is 18.5% (v/v) methyl alcohol. If the bottle contains 2.49L of solution, what is the volume (V) in milliliters of methyl alcohol? A 6.00 % (m/v) NaCl solution ...
March 3, 2015

chenistry
nevermind, I figured it out... ughhhhh
March 3, 2015

chenistry
this is confusing me so bad!! Nitrogen gas reacts with hydrogen gas to produce ammonia by the following equation: N2(g)+3H2(g)→2NH3(g) If you have 5.79g of H2, how many grams of NH3 can be produced? I said, 2/3 *5.79 = 3.86 but that's not the answer.. it says the ...
March 3, 2015

Chemistry Dr. Bob
Balanced Equation: 2PbS+ O2 --> 2PbO +2SO2 How many grams of oxygen are required to react with 0.124mole lead(II) sulfide? Ummmm.. I tried to convert it to grams? 0.124 mol * molar mass of PbS (239.3) = 29.67 g of PbS then tried to plug it into the equation.. 1/2 * 29.67/...
March 3, 2015

Chemistry
Ok, I'm trying my best here, I'm learning, and I'm thinking I'm on a roll, until I can't get the right answer again..... First.. the butane question Calculate the mass of Butane needed to produce 82.7g Carbon dioxide. 2C4H10 +13 O2--->10H2O +8CO2 Ratio ...
March 2, 2015

Chemistry
Calculate the mass of water produced when 3.09g of butane reacts with excess oxygen. 2C4H10 + 13O2-->10H2O + 8CO2 Help.
March 2, 2015

chemistry
I need to know how to figure this out, step by step... Don't assume I know anything.. Break it down for me like I'm a 5 year old... I'm really horrible at figuring out where to even begin... what steps to use.. etc.. Thank you!! CO2(g)+4H2(g)→CH4(g)+2H2O(g) ...
March 2, 2015

Chemistry
Need Help! 1. Ammonia is produced by the reaction of hydrogen and nitrogen. N2(g)+3H2(g)→2NH3(g)ammonia How many moles of N2 reacted if 0.65mole NH3 is produced? How many moles of NH3 are produced when 1.2moles H2 reacts? 2.In the acetylene torch, acetylene gas (C2H2) ...
February 28, 2015

Chemistry
nevermind, I figured it out!!! I'm getting better!! 3.80* mass of NaCl (58.4) =222g
February 27, 2015

Chemistry
I'm having a brain malfunction... how to calculate how many grams are in a mole of something? How many grams are in 3.80mol of sodium chloride (NaCl)?
February 27, 2015

Chemistry
Ammonia is produced by the reaction of hydrogen and nitrogen. N2(g)+3H2(g)→2NH3(g)ammonia How many moles of N2 reacted if 0.65mole NH3 is produced? How many moles of NH3 are produced when 1.2moles H2 reacts?
February 27, 2015

Chemistry
Ok, I know how to balance chemical equations, however, I don't know how to tell if it is a S, L, aq, or g? How am I supposed to know this?? Mg(s)+AgNO3(aq)→Mg(NO3)2(aq)+Ag(s) Express your answer as a chemical equation. Identify all of the phases in your answer. ...
February 27, 2015

Chemistry
the calculator said it.. I didn't do anything but plug it in.. sorry, thanks for help
February 27, 2015

Chemistry
Dr. Bob222, Calculate the moles of C2H6 in 8.60×1023 molecules of C2H6. I did what you said, I got 8.60*10^23*(1mole/6.02*10^23) = 1.43*10^46??? This is not the answer.. am I doing something wrong?
February 27, 2015

Chemistry
I'm doing things on Mastering Chemistry dot com my homework.. I thought i was doing it right.. I was doing 9.9 * (6.02E23/1) It didn't like my significant figures.. It was wanting 6.0 * 10^24 as the answer, not 5.95 ugh... Thanks Dr. Bob.. Will probably be posting more...
February 27, 2015

Chemistry
UMM.. I keep coming up with the wrong answer? How do I calculate this? 1. Calculate the number of Li atoms in 9.9 moles of Li. Express your answer using two significant figures. 2. Calculate the number of CO2 molecules in 3.13×10−2 mole of CO2. 3.Calculate the ...
February 27, 2015

Chemistry to DrBob222
DrBob222 You are an amazing person! I have received more help from you the past two days that I have this whole semester from my instructor! You have an amazing gift of breaking things down to understand completely! Where are you from? Do you get paid for this somehow? look me...
February 26, 2015

Chemistry
Ok, Need some more help... This is what I have so far. 4. Urea (NH2)2CO is prepared by reacting ammonia with carbon dioxide. The byproduct is water. 637.2g of ammonia are reacted with 787.3 g of carbon dioxide. molar mass:NH3=17 CO2=44 CO(NH2)2=60.1 a. (10 points) Write a ...
February 26, 2015

Chemistry Drbob222
Dr. Bob222 Please don't get frustrated with me, I'm really trying to figure this out... UGH!! I'm starting over again... Please advise... . Consider the following chemical equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) were ...
February 26, 2015

Chemistry
Ok, Need some more help... This is what I have so far. 4. Urea (NH2)2CO is prepared by reacting ammonia with carbon dioxide. The byproduct is water. 637.2g of ammonia are reacted with 787.3 g of carbon dioxide. molar mass:NH3=17 CO2=44 CO(NH2)2=60.1 a. (10 points) Write a ...
February 26, 2015

Chemistry
Percent yield is equal to the actual amount yield divided by the theoretical amount, so: 7.91 x 10^6 all divided by 8.94 x 10^6 = 88.5% yield Is this right???
February 26, 2015

Chemistry
3.54 x 10^7 g TiCl4 x (1 mol/189.68 g) x (1 mol Ti/1 mol TiCl4) x (47.88 g/1 mol) = 8.94 x 10^6 g Ti
February 26, 2015

Chemistry
Dr. Bob222 Please don't get frustrated with me, I'm really trying to figure this out... UGH!! I'm starting over again... Please advise... . Consider the following chemical equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) were ...
February 26, 2015

CHEMISTRY
Someone please tell me if I'm doing this right... It's due tonight!! Dr. Bob222, Yesterday I posted a question and you answered me with how to calculate it.. Can you tell me if I'm doing this correctly?? Please! Consider the following chemical equation: TiCl4(g) + ...
February 25, 2015

Chemisty
Someone please tell me if I'm doing this right... It's due tonight!! Dr. Bob222, Yesterday I posted a question and you answered me with how to calculate it.. Can you tell me if I'm doing this correctly?? Please! Consider the following chemical equation: TiCl4(g) + ...
February 25, 2015

Chemistry
Dr. Bob222, Yesterday I posted a question and you answered me with how to calculate it.. Can you tell me if I'm doing this correctly?? Please! Consider the following chemical equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) were reacted ...
February 25, 2015

Chemistry
Thanks DrBob222!!! You have helped me so much!!
February 24, 2015

Chemistry
Consider the following chemical equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) were reacted completely and 7.91×106g of Ti(s) was obtained in the experiment. a. Calculate the theoretical yield of Ti(s). b.What is the actual yield of Ti(...
February 24, 2015

statistics
Determine the critical region and the critical values used to test the following null hypotheses: a. Ho: μ = 55 (≥), Ha: μ < 55, α = 0.02 b. Ho: μ = −86 (≥), Ha: μ < −86, α = 0.01 c. Ho: μ = 107, Ha: μ &#...
February 20, 2015

algebra 2
(ab)^2+2ab-2ab-4 (ab)^2-4
September 30, 2014

Chemistry
A 1N solution of NaOH is diluted 4/20 then rediluted 1:50. What is the final normality? How many grams of NaOH are present in 100ml of the final solution? I sort of understand the basic concept, but I don't really know how to do normality problems.
May 20, 2014

Managerial Accounting
If given the Selling price, the direct labor costs and other variable costs how do you determine the number of direct labor hours per unit?
March 31, 2013

psychology
Hi I have 2 questions i am searching for the proper answer on and it keep finding conflicting information> 1) Psychologist who believe in ___ are most likely to attempt to understand diversity in ethnic background as an influence on behavior: individual differences free ...
November 26, 2012

maths
find the base of an isocelus triangle base 12cm and its peremeter is32cm.find the area of the triangle
May 21, 2012

science
Use this reaction to answer the question: 2KClO3 -> 2KCl + 3O2. If I start with 65g KClO3, how many mol O2 will be formed? How many g O2? If I need to produce 299g KCl, how many mol of KClO3 do i need to start with? How many g KClO3?
April 24, 2012

Math
I tried 3x + 2x = 24 5x = 4.8 then multiply 3 • 4.8 = 15.4 and 2 • 4.8 = 9.6 which means 14 tvs & 10 radios would be left
February 26, 2012

Math
I forgot to mention there were 18 radios counted on Monday
February 26, 2012

Math
At the beginning of the week, an electronics store took count of how many tvs and radios there were in the stockroom. The manager found that there was a ratio of 3 tvs for every 2 radios. At the end of the week, the manager counted 24 boxes left in the stockroom. Using the ...
February 26, 2012

phi 301
"All dogs like bones; Sirius is a dog; therefore Sirius likes bones" may commit which fallacy?
January 28, 2012

Physics
Two identical rollers are mounted with their axes parallel, in a horizontal plane, a distance 2d = 40.4 cm apart. The two rollers are rotating inwardly at the top with the same angular speed. A long uniform board is laid across them in a direction perpendicular to their axes...
January 5, 2012

Physics
Two identical rollers are mounted with their axes parallel, in a horizontal plane, a distance 2d = 40.4 cm apart. The two rollers are rotating inwardly at the top with the same angular speed. A long uniform board is laid across them in a direction perpendicular to their axes. ...
January 4, 2012

Physics
Two identical rollers are mounted with their axes parallel, in a horizontal plane, a distance 2d = 40.4 cm apart. The two rollers are rotating inwardly at the top with the same angular speed. A long uniform board is laid across them in a direction perpendicular to their axes. ...
January 4, 2012

Physics
Two identical rollers are mounted with their axes parallel, in a horizontal plane, a distance 2d = 40.4 cm apart. The two rollers are rotating inwardly at the top with the same angular speed. A long uniform board is laid across them in a direction perpendicular to their axes. ...
January 3, 2012

Physics
Wouldn't the formula be T=2Pisqrt(I/mgd) where you solve for d, but my question iss do I add the two masses or am I over thinking this one
January 3, 2012

Physics
but wouldn't the mass and the Length of the rod come in play?
January 3, 2012

Math
How many different arrangements can be made with the letters from the word ORANGE?
January 3, 2012

physics
You are standing 7 feet from one speaker and 13 feet from another. Both speakers are producing the same sound. If the combined sound from both speakers is especially loud at your location, which of the following could be the wavelength of the sound? Choose all that apply. 1 ...
December 8, 2011

physics
A woman is sitting in a boat at anchor on a lake. Her boat bobs up and down once every 2.0·s. She notices that when the front of her 3.0·m long boat is at one wave crest, a second crest is at the middle of her boat, and a third is at the end. What is the ...
December 8, 2011

Algebra 2
Okay, thank you for your help! I will change the order of my answer.
December 8, 2011

Algebra 2
Write the expression as a complex number in standard form. 3-3i/4i I'm not sure about this problem, but I think the answer is -3/4i-3/4. Could anyone help me please?
December 8, 2011

Math
Okay, I wasn't sure if my answer was right, so thank you!
December 8, 2011

brown
parker wants to buy as many toys as she can with her 10$she can buy individule ponies for 2$ each or a set of 2 dolls for $3 what she she buy and why what do you need to find out what operations will you use why write a number sentence to show how you solved the problem label ...
November 9, 2011

Chemistry
You have a stock solution of 15.8 M NH3 . How many milliliters of this solution should you dilute to make 1350 mL of 0.300 M NH3
September 13, 2011

ANT 101
The process of cultural transmission from one generation to another is called:
June 8, 2011

Math
A watch cost $75.99. If the sales tax rate is 6.25%, what is the amount of sales tax? Please show work or the explanation you used!
May 28, 2011

Chemistry (Electrons in Atoms)
thanks
May 22, 2011

Chemistry (Electrons in Atoms)
True or False. 1)Electrons give off light as they drop to lower energy levels. 2)Electrons travel around the nucleus as waves. 3)A photon of low frequency light has more energy than a photon of high frequency light. 4)Orbitals with equal energy levels each contain one electron...
May 22, 2011

algebra
The length of a rectangle is 5 inches more than three times the width. The perimeter is 98 inches. Find the length and width
May 2, 2011

physics
Thanks. I'm not good with the right hand rules and the websites I'm finding aren't really helping.
April 7, 2011

physics
A wire carries a current north. Above the wire the magnetic field is directed _________. Is it east? You are looking at a coil carrying a current clockwise. The magnetic field at the center of the coil is directed _________. Is it right?
April 7, 2011

math
I will try. This will help me to start and gave me an idea. Thank you very much.
January 25, 2011

math
I am a third grader and have a homework of sketching and labeling all possible rectangles with perimeter of 30 cm and sides whose lengths are whole numbers. I am confuse, i need help please.
January 25, 2011

College Math
this isnt home work
December 12, 2010

College Math
For questions 1-2, apply the quadratic formula to find the roots of the given function, and then graph the function. 1. f(x) = x2 + 4 (6 points) g(x) = x2 - x – 12 For questions 3-4, factor the quadratic expression completely, and find the roots of the expression. 1. (3 ...
December 12, 2010

college math
apply the quadratic formula to find the roots of the given function, and then graph the function. f(x) = x2 - 4 g(x) = x2 - x - 12
December 10, 2010

college math
apply the quadratic formula to find the roots of the given function, and then graph the function. f(x) = x2 - 4 g(x) = x2 - x - 12
December 10, 2010

market and sales
the most common basis for market segmentation is demographics psychographics media usage cost analysis
December 1, 2010

biology
The sex ratio(number of females vs. males) of which of the following species might be most affected by global warming?A.Humans b.bees c.birds d.Turtles
October 29, 2010

algebra
-2(x-2)=2[x-4(x-2)+x]
September 20, 2010

physics
What is the average time interval between heartbeats? what is the average time between a hummingbird flaps its wing?
September 14, 2010

geometry
If an arc makes a central angle of 98 degrees is it a major or minor arc? Explain??
June 10, 2010

chemistry
What affect does salt have on ice water? Is there a term for it and a website that explains this?
June 3, 2010

chemistry
How are the formation of aqueous solutions of sodium chloride and sucrose similar?
May 25, 2010

chemistry
Thank you!
April 26, 2010

chemistry
Is this statement accurate? the boiling point of the distilled water was 99°C. After five minutes, the temperature still stayed the same; it remained constant. The liquid was becoming a gas. Phase change means there is an energy change. When the temperature of the water ...
April 26, 2010

english
the activity of scaling rocky cliffs
March 14, 2010

Physics
Joshua has a mass of 60kg and stands next to a wall ona frictionless skateboard. If he pushes the wall with a force of 30N, how hard does the wall push on him? Show that Joshua accelerates at .5 m/s2 away from the wall.
February 7, 2010

algebra
To get the x intercept you are going to want to isolate the x so that your problem equals x SO try dividing the 4 in 4x by itself to cancel it out. Since you have to do the same thing on both sides, divide the 4 by 4y and by 12 then you have x=y-3. Here is an example of how to...
August 16, 2009

AED 204
Hey I am mormon so i might be able to answer some of these for you from a mormon perspection if that is what you are asking: Pro or Con-prayer in school: not really touched on no strong church beliefs but there are no problems with this found in the church -creationism vs. ...
August 16, 2009

english
Does anyone have any ideas for an UNpersuasive essay? Instead of doing a normal essay, my class is doing an essay on anything that's crazy that people would normally not believe but if I use facts and other information, maybe they might believe me. I wanted to do maybe ...
May 26, 2009

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