Saturday

July 30, 2016
Total # Posts: 894

**Chemistry (Acids and Bases)**

thank you very much
*March 20, 2011*

**Chemistry (Acids and Bases)**

THIS HAS TWO PARTS NaOH(s) was added to 1.0 L of HCl(aq) 0.42 M. 1) Calculate [H3O+] in the solution after the addition of 0.13 mol of NaOH(s). 2) Calculate [H3O+] in the solution after the addition of 0.81 mol of NaOH(s).
*March 20, 2011*

**Chemistry (Acids and Bases)**

thank you very much
*March 20, 2011*

**Chemistry (Acids and Bases)**

The natural pH of rainwater is 5.6. The acidity of rainwater is caused by the dissolution of (TRUE OR FALSE) boric acid sulfuric acid carbonic acid calcium carbonate calcium oxide nitric acid
*March 20, 2011*

**algebra**

the formula r= -0.075t + 3.85 can be used to predict the world record for the 1500 meter run, t years after 1930.find an inequality that identifies the years in which the world record will be less than 2.8 minutes
*March 16, 2011*

**science**

what is an explanation for the relationship between currents and the brightness of a light bulb??
*February 21, 2011*

**english**

I am having some serious problems with parallelism. I do not understand how to use parallelism. I've read the lesson in my textbook and I've looked at different websites that help explain it, but I just can't get it. Can anyone break this down in "layman's...
*February 18, 2011*

**Statistics**

The length of time it takes college students to find a parking spot in the library parking lot follows a normal distribution with a mean of 4.0 minutes and a standard deviation of 1 minute. Find the probability that a randomly selected college student will take between 2.5 and...
*February 13, 2011*

**Algebra 1**

Explain the differences between solving these two equations: Brake down the steps. log3(x - 1) = 4 and log3(x - 1) = log34 )
*February 8, 2011*

**Algebra 1**

Explain the differences between solving these two equations: •log3(x - 1) = 4 AND log3(x - 1) = log34 I think it has to deal with the formulas?
*February 8, 2011*

**Andy**

Name: Lesson 3 Assignment.Instructions Explain the differences between solving these two equations: •log3(x - 1) = 4 and log3(x - 1) = log34. I think it has to do with the formulas
*February 8, 2011*

**Calc-slopes & concavity**

1. Let f(x)=x^3-3x+2 a.) Find the equation of the line tangent to the graph of y=f(x) at x=2 b.) For what values of x is the function increasing? c.) For what values of x is the graph concave down?
*January 23, 2011*

**English 12**

okay thank you!
*January 23, 2011*

**English 12**

In your understanding is this thesis statement clear enough? What other improvements would you make? The topic is "Theme of Overcoming struggle in the course text" Many themes are presented in: Hamlet, Death of a Salesmen, Life of Pi, the Road, and the Kite Runner ...
*January 23, 2011*

**IT computer memory**

No, incorrect. Be carefull with this, your: 18MB x 10^6 x 8 bits = 144,000,00 Should in fact be: 18mb x 2^20 x 8 bits = 150,994,994 Your second part is correct, so its 4 megabits per second = 4 x 10^6 = 4,000,000 Answer: 150994994 / 4000000 = 37.75 seconds.
*January 13, 2011*

**math**

A student claims that every prime greater than 3 is a term in the arithmetic sequence whose nth term is 6n + 1 or in the arithmetic sequence whose nth term is 6n - 1. Is this true? if so, why?
*December 23, 2010*

**11th grade math **

The equation Ax^2 + 4y^2 = 16 represents an ellipse. Find all values of A such that its intersection with y = |x| has coordinates (x,y) which are integers.
*December 19, 2010*

**Math**

The equation Ax^2 + 4y^2 = 16 represents an ellipse. Find all values of A such that its intersection with y = |x| has coordinates (x,y) which are integers.
*December 16, 2010*

**physicis**

How much power does it takes to do 104 J of work in 8 seconds
*December 13, 2010*

**physicis**

How far will 350 J raise a 7kg mass?
*December 13, 2010*

**English**

Can anyone see any rhetorical device in this sentence? His father’s voice: You gonna let ’em push you around like that, boy? “No sir, Daddy,” Perry whispered. “I sure as hell ain’t.”( Sigler 227)
*December 8, 2010*

**math**

Sum of a 3 digit # is 24. Ones digit is 2 more than 2xs the hundred dig. Tens dig is 1 more thn 3xs the hund dig. Wats the #??
*December 7, 2010*

**chemistry**

2 Na202 + 2H20 -> 4NaOH + 02 When 200.g of Na202 were reacted, 32.0 g of 02 were collected. The yield of 02 collected was (how many percentages)
*December 7, 2010*

**English 12 U**

Please ignore my previous post, I accidentally posted my rough draft Okay for English 12 U, I'm doing a literary essay for Life of Pi, by Yann Martel. The topic of my essay is Martel (author's) depiction of setting in Canada and India. (Role of setting) I'd like ...
*December 1, 2010*

**Math**

Many thanks
*November 28, 2010*

**Math**

The path of a cliff diver as he dives into a lake is given by the equation y= -(x-10)^2+75, where y meters is the divers height above the water and x meters is the horizontal distance travelled by the diver. What is the maximum hight the diver is above water? Is the answer to ...
*November 28, 2010*

**Math**

The path of a cliff diver as he dives into a lake is given by the equation y= -(x-10)^2+75, where y meters is the divers height above the water and x meters is the horizontal distance travelled by the diver. What is the maximum hight the diver is above water? How can I find ...
*November 28, 2010*

**English 12**

Yesterday, i posted a question about writing a thesis for Life of Pi. However i'm not sure how to develop a thesis from my topic. The topic of my essay is "Yann Martel's depiction on the role of setting in India and Canada". If anyone can kindly help me to ...
*November 21, 2010*

**English 12**

alright thank you, ill post a question later on when i develop a thesis
*November 20, 2010*

**English 12**

Okay, for English 12 im doing a semiar on Yann Martel's book, "Life of Pi" The topic of my essay is "martel depiction of Canada and India= the role of setting" My main body paragraphs are Setting in Canada Setting in India Setting in the Ocean what im ...
*November 20, 2010*

**physics**

you're not following the sig fig rule- it's -110 because you can only have 2 significant figures.
*November 18, 2010*

**Finance**

I need help writing scenario style questions for a school business management class
*November 7, 2010*

**Bio Lab**

You need to prepare medium for your culture cells. Your salt solution is 10x concentration, dilute to 1x for use. You also need to add fetal bovine serum for a final concentration of 10%. What would you add of each for the correct final concentrations in a liter of media?
*November 3, 2010*

**Organic Chemistry**

What would have happened if we had forgotten to neutralize the aqueous solution before recrystallization?
*November 3, 2010*

**Physics**

Sam is taking his girlfriend Sally out for a ride in his boat. He starts out at rest. He accelerates with an acceleration of 0.263 m/s^2 for 92.1 s. At that time Sally decides they are going fast enough and the boat moves at constant speed for a distance of 286 m. Then Sally ...
*October 28, 2010*

**science**

Do plants grow better with tap water or distilled water?
*October 23, 2010*

**chem--need help, please!!!**

thank you very much, DrBob222!
*October 20, 2010*

**chem--need help, please!!!**

Ka for benzoic acid, C6H5COOH, 6.5x10^-5. Calculate the pH of solution after addition of 10.0, 20.0, 30.0, and 40.0 mL of 0.10 M NaOH to 40.0 mL of 0.10 M Benzoic acid. PLEASE CHECK MY ANSWER!!!!! My answer is: Moles acid = 0.040 L x 0.10 M = 0.0040 Moles base = 0.010 L x 0.10...
*October 20, 2010*

**social studies**

What is the base for the earth's hills and mountains?
*October 17, 2010*

**physics**

does each of the two lenses used in a microscope produce a magnification of the object being viewed?
*October 17, 2010*

**AP Human Geography**

idiocy
*October 15, 2010*

**Biology**

Are there any viruses/diseases in the tundra?
*October 15, 2010*

**math**

marcias house is approx. 10 miles east of the airport. a jet is flying directly over her house after taking off from the airport and flying approx. 12 miles. approx how many miles high is the jet when it flys over marcias house?
*October 11, 2010*

**math**

when a marble hits a wall at a 22 degree angle, what is the measure of the angle between the two paths of the marble?
*October 11, 2010*

**History**

What difficulties did the Pilgrims encounter in their attempt to gain passage to the New World?
*October 8, 2010*

**chem**

what are the net ionic equations for ClO3^-; Zn^2+ undergo hydrolysis?
*October 2, 2010*

**math**

the equation is f(x) = (1/sq. root of 1-x^2) 1. f(x) is never zero. 2. 0 is in the domain of f 3. All negative real numbers are in the domain of f 4. All positive real numbers are in the domain of f 5. 1 is in the domain of f 6. f(x) is never negative 7. f(x) is never positive...
*September 23, 2010*

**physics**

The pilot of an airplane traveling 180 km/h wants to drop supplies to flood victims isolated on a patch of land 125 m below. The supplies should be dropped how many seconds before the plane is directly overhead? ______s
*September 21, 2010*

**physics**

A ball is thrown horizontally from the roof of a building 60 m tall and lands 45 m from the base. What was the ball's initial speed? _______m/s
*September 21, 2010*

**Chemistry**

Than from here I need to find: Using the volume of solvent calculated in step 1, calculate how much sulfanilamide will remain dissolved in the mother liquor after the mixture is cooled to 0 degree Celsius? Can you please explain?
*September 21, 2010*

**Chemistry**

thank you!
*September 21, 2010*

**Chemistry**

Please help the question that I got is: Calculate how much 95% ethyl alcohol will be required to dissolve 075g sulfanilamide at 78 degree Celsius. Knowing that solubility of sulfanilamide is 210 mg/ml at 78 degree Celsius, 14mg/ml at 0 Degree Celsius. please explain.
*September 21, 2010*

**Science**

thank you
*September 21, 2010*

**algebra 8th**

ok gat it
*August 31, 2010*

**algebra 8th**

YOU THINK? BUT I HAVE TO DO ALL THE PROBLEM
*August 31, 2010*

**algebra 8th**

ADD OR SUBTRACT> 5.2-2.5 HOW DO I DO THIS?
*August 31, 2010*

**Physical Science, ipc**

C
*July 15, 2010*

**chem**

What is the total pressure in mm Hg of a gas mixture containing argon gas at 0.25 atm helium gas at 350 mm,Hg, and nitrogen gas at 360 torr.
*July 10, 2010*

**chem**

What is the volume in liters of 3.2 moles methane gas, CH4, at 12degrees C and 1.52 atm?
*July 10, 2010*

**chem**

An airplane is pressurized to 650mmHg , which is the atmospheric pressure at a ski resort at 1.30×10^4 altitude.If air is 21 % oxygen, what is the partial pressure of oxygen on the plane?
*July 10, 2010*

**biochemistry**

an intramalecular meds is given at 5.0mg/kg of body weight. if you give 425mg of medicatioon to a pt. what is the ppTIENT weight?
*July 5, 2010*

**biochemistry**

ordered 1.0g of tetracycline to be given every 6 hours. on hand 500mg. how many will we need for 1 days treatment?
*July 5, 2010*

**Literature**

During the Renaissance, people rediscovered the literature of the past. True or False? At that time there was an enormous renewal of interest in and study of classical antiquity. So True, right? Just wanna make sure, Thanks.
*July 3, 2010*

**personal finance**

Sue and Tom Wright are assistant professors at the local university. They each take home about $42,000 per year after taxes. Sue is 37 years of age, and Tom is 35. Their two children, Mike and Karen, are 11 and 9. Were either one to die, they estimate that the remaining family...
*June 27, 2010*

**personal finance**

Sue and Tom Wright are assistant professors at the local university. They each take home about $42,000 per year after taxes. Sue is 37 years of age, and Tom is 35. Their two children, Mike and Karen, are 11 and 9. Were either one to die, they estimate that the remaining family...
*June 27, 2010*

**chem**

Calculate the specific heat (\rm{J/g \; ^\circ C}) for a 21.5 g sample of a metal that absorbs 685 J when temperature increases from 42.1^\circ C to83.2^\circ C.
*June 10, 2010*

**chem**

Calculate the specific heat (\rm{J/g \; ^\circ C}) for a 18.5-\rm g sample of tin that absorbs 183 {\rm J} when temperature increases from 35.0 ^\circ \rm C to 78.6 ^\circ \rm C.
*June 10, 2010*

**bio**

A typical adult body contains 55 \% water. If a person has a mass of 70.0 kg, how many pounds of water does she have in her body?
*June 10, 2010*

**Biology**

can anyone please help me answer this question: How is DNA put together into chromosomes?
*June 5, 2010*

**chemistry**

Complete and balance the displayed half reaction in neutral aqueous solution taking into account the electrons. Mg(s) → Mg2+(aq)
*June 1, 2010*

**biology**

Does asexual reproduction of sponges depend on time of year, availability of food, or other factors?
*May 30, 2010*

**Biology**

sorry, this link does not answer these specific questions!
*May 30, 2010*

**Biology**

Under what conditions does asexual reproduction in sponges occur? Does it depend on time of year, availability of food, or other factors?
*May 30, 2010*

**Science**

What is the pH of a 2.62 x 10^-2 M HBr solution? thanks
*May 25, 2010*

**chem can u check answer please**

thanks so much
*May 23, 2010*

**chem can u check answer please**

Which is NOT a chareteristic property of acids? A: react with carbonate to yield CO2 gas B: taste sour C: neutralize bases D; turns litmus red to blue E:reacts with metal to yield H2 gas I reckon its D because isnt it the other way around ? Blue to red ...not...red to blue Any...
*May 23, 2010*

**chem can u check answer please**

what is the hydrogen ion concentration of an aqueous solution with a pOH of 9.262? I got 5.47X 10 ^-10 is this correct? Thanks Andy
*May 23, 2010*

**chem can u check answer please**

the solubility of silver sulfate in water is 0.223%(w/v) at 35 degrees celsius.calculate the solubility product of this salt at this temp. I got 1.46 X 10^-6 M is this right please thanks Andy
*May 23, 2010*

**Chem/science**

what is the ph of 2.62 x 10 ^-2 M HBr solution? I get 5.94 is that right? thanks andy
*May 23, 2010*

**Chem/science**

What is the conjugate acid of HC5H6O4-?? Is it HC5H6O42-?? thanks andy...
*May 23, 2010*

**Chemistry**

Why can't benzene dissolve sodium chloride?
*May 18, 2010*

**3rd grade**

Ineed help with the synonyms and antonyms ex. perfect, frawless is this an antonym or synonym?
*May 17, 2010*

**SCIENCE?CHEMISTRY*****

Dr Bob each time i do a problem on this site I have to print out answer....is there any way you know how to save it to usb stick???? I cant for the life of me find a save feature... also how do YOU when you give us a link to a site ...make it appear in blue and all we have to ...
*May 16, 2010*

**SCIENCE?CHEMISTRY*****

thanks dr bob Andy
*May 16, 2010*

**SCIENCE?CHEMISTRY*****

Am using the inventory method at moment but am stuck on how fill i the inventory for __Agl+__Fe2(CO3)3--> __Fel3+__Ag2CO3 I think the brackets are throwing me Hows this element b4 after ------------------------------------ Ag 1 2 l 1 3 Fe 6 1 CO 3 3 I dont know if this is ...
*May 16, 2010*

**SCIENCE?CHEMISTRY*****

well done thanks... Andy
*May 14, 2010*

**SCIENCE?CHEMISTRY*****

an 56 Fe 2+ particle has how many protons neutrons amd electrons??? 56 2+ Fe Thanks Andy
*May 14, 2010*

**SCIENCE?CHEMISTRY*****

how many dozens of dust particles are in 2.45 g if each particle has a mass of 2.51 x 10^-4 grams...? I dont have a clue!!!!!! Thanks Andy
*May 14, 2010*

**SCIENCE?CHEMISTRY*****

thanks..... andy
*May 14, 2010*

**SCIENCE?CHEMISTRY*****

DR Bob, can you go thru the steps to work this out please.... how many grams of alcohol with a density of 0.900 g/cm ^3 (cm cubed) will have the same volume as 20.0g of mercury,with a density of 13.6 g/cm ^3 Do you have to find the volume of mercury first??? I know the answer ...
*May 14, 2010*

**chemistry**

thanks..andy
*May 13, 2010*

**chemistry**

The solubility of MnS was found to be 0.000963 g per 700 mL of water. Calculate the solubility product constant (Ksp) for MnS. MnS (s)=Mn2+ (aq) + S2- (aq)
*May 13, 2010*

**chemistry**

The solubility product constant (Ksp) for the dissolution of PbSO4 as represented by the chemical equation is 1.7x10-8. PbSO4 (s)= Pb2+ (aq) + SO42- (aq) Calculate the mass (g) of PbSO4 that dissolves in 1100 mL of water.
*May 13, 2010*

**SCIENCE/CHEM**

thanks so much....andy
*May 12, 2010*

**SCIENCE/CHEM**

Dr Bob Is it true that only TWO molecules of water are required to balance the equation for the reaction of HCL with Calcium Hydroxide.(calcium chloride is the other product....why??? Thanks andy
*May 12, 2010*

**SCIENCE/CHEM**

thanks.... andy
*May 12, 2010*

**SCIENCE/CHEM**

Dr BOB, Can you show me how to do the balanced equation please I am shocking at them Thanks AndyWhats the simple way to explain balancing equations so i get it please....because i am horrible at them... Thanks andy
*May 12, 2010*

**SCIENCE/CHEM**

the purity of zinc is to be determined by measuring the amount of hydrogen formed when a weighed sample of zinc reacts with an excess of HCL acid.the sample weighs 0.198 grams. what amount of hydrogen gas at STP will be obtained if the zinc is 100% pure? need a metric answer ...
*May 12, 2010*

**SCIENCE/CHEM**

thanks..... andy
*May 12, 2010*

**SCIENCE/CHEM**

the volume of a sample of gas is 650.ml at STP. what volumes will the sample occupy at 0.0degrees celsius and 950.torr??? is it 650.ml?
*May 12, 2010*