Wednesday

March 4, 2015

March 4, 2015

Total # Posts: 118

**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*

**Algebra Reiny question**

The two values are s=3,-3 is this the right values?
*May 4, 2009*

**Algebra**

Find all the numbers for which the rational expression is undefined s^3-6x/ s^2-9 Thanks for the help
*May 4, 2009*

**History**

The "Critical Period" took place during the years when... w. the United States was governed by its 1st president x. George Washington served as the 1st president y. None of these answers are correct
*March 22, 2009*

**8th grade**

what is the difference between a compressional wave with a large amplitude and one with a small amplitude
*February 16, 2009*

**Geography**

The Bay of Fundy (or the Fundy Bay) is east of Maine.
*February 12, 2009*

**chemistry-0.1NHCl**

Hi, A bottle of concentrated Hydrochloric acid (HCl) has the following information stated on it: - Hydrochloric acid 37% 1L ~ 1190kg How do I prepare 0.1N HCl from this concentrated HCl?
*December 18, 2008*