Friday

December 9, 2016
Total # Posts: 531

**Chemistry**

A gas diffuses twice as fast as CF4 (g). The molecular mass of the gas is: I'm not sure how to figure this out without the rates of diffusion.

*February 11, 2014*

**Math**

if a 16 ounce can of soup costs 64 cents, what is the cost for each ounce of soup?

*January 29, 2014*

**Earth Science**

partial freezing

*January 16, 2014*

**history**

thanks

*January 7, 2014*

**Math**

Three of these methods give the correct area of the figure. Which method does NOT?

*December 10, 2013*

**physics**

A 5.0 kg \rm kg, 52-cm \rm cm-diameter cylinder rotates on an axle passing through one edge. The axle is parallel to the floor. The cylinder is held with the center of mass at the same height as the axle, then released. a)What is the magnitude of the cylinder's initial ...

*December 6, 2013*

**SS again please help me asap**

A Spycrab, you are a life saver! thank you for the 100%

*November 21, 2013*

**Alg 2**

It did help. Thank you so much! cx

*October 25, 2013*

**Alg 2**

The value of y varies directly with x. If y = 64 when x is 16, what is x when y is 288?

*October 25, 2013*

**English**

In the following sentence identify the appositive or appositive phrase and the noun or pronoun defined by the appositive. Mr. Murray, the Scoutmaster, likes to hike. Appositive? Noun or pronoun defined?

*October 1, 2013*

**Chemistry**

How to calculate Q in Nernst Equations, we used 0.10M solutions in all of our half cells. Nernst equation: Ecell = E0cell - RT/nF ln Q Overall reactions: Cu(s) + Pb2+(aq) ~ Cu2+(aq) + Pb(s) and 3Pb(s) + 2Al3+ ~ 3Pb2+ 2Al(s) Thank you!

*May 14, 2013*

**Chemistry**

Using your experimental data, calculate E0cell. Standard voltaic cells contain 1M solutions, but we used 0.10M solutions in all of our half cells. Use the Nernst equation to calculate the standard cell potential (E0cell) from your measured Ecell and Qrxn. Data: Nernst Equation...

*May 14, 2013*

**Math**

An airplane is flying at an altitude of 6 miles and passes directly over a radar antenna. When the plane is 10 miles away, the radar detects that the distance is changing at a rate of 240 mph. what is the speed of the plane? This is an implicit differentiation problem

*May 13, 2013*

**chemistry**

No. this is the sample I did. Cu+(s)+/Cu2+aq)//Al3(aq)+/Al(s) is this right? Anode = Cu+(s)+/Cu2+(aq) - +0.337 Cathode = Al3+(aq)+/Al(s) - -1.66 Overall redox reactions: -0.337 - -1.66 = 1.323?

*May 8, 2013*

**chemistry**

A. Find and list all of the different half- cell combinations. Hint 15 combinations! 1. Copper/ Cu2+ 2. Lead/ Pb2+ 3. Magnesium/ Mg2+ 4. Zinc/ Zn2+ 5. Iron/Fe2+ 6. Aluminum/ Al3+ B. write the half reactions of each combination and the overall redox reaction. Please help! Thank...

*May 8, 2013*

**Chemistry **

What is the Ka of the amino acid serine if it is 34.5% dissociated at pH- 9.46?

*May 4, 2013*

**Chemistry**

ok thank you!

*April 30, 2013*

**Chemistry**

dG=? . how do I start this problem? Do I use dG= -RT*ln*K? dG=-(0.008314 kj/k*mol) (61+ 273.15) ln (29.24)?? I tried this and it is wrong.

*April 30, 2013*

**Chemistry**

DrBob222, I don't know how to solve this problem either. And yes, this is the question for this problem. I even double check it. Please help. Chloroform (CHCL3) has a normal boiling point of 61 'C and an enthalpy of vaporization of 29.24 kJ/mol. What is the value of ...

*April 30, 2013*

**Chemistry**

Chloroform (CHCL3) has a normal boiling point of 61 'C and an enthalpy of vaporization of 29.24 kJ/mol. What is the value of delta Gvap (in kJ) at 61'C for chloroform?

*April 30, 2013*

**Chemistry**

I realized where I made a mistake for this problem. This time, I got this one right. Thank you so much!

*April 30, 2013*

**Chemistry**

The following thermodynamic data was obtained for an unknown compound. Delta Hvap = 31.3 kj/mol and Delta S Vap= 79.7 kj/mol .Calculate the normal boiling point of this compound in Celcius.. Thank you! Chemistry - DrBob222, Tuesday, April 30, 2013 at 12:31am dG = dHvap - ...

*April 30, 2013*

**Chemistry**

At 20 degree celsius, Ka for an unknown monoprotic weak acid is 0.00088. Calculate the Delta G (in kJ/mol) for the reaction of this unknown acid with water. HA(aq) + H2O(l) <--> H3O+(aq) + A-(aq)

*April 30, 2013*

**chemistry**

Calculate the enthalpy of fusion of naphthalene (C10H8) given that its melting point is 128 Celsius and its entropy of fusion is 47.7 J (k*mol) .

*April 29, 2013*

**chemistry**

Given that for the vaporization of benzene Hvap= 30.7 kj/mol and Svap= 87.0 J(K * mol) , calculate Delta G (in kJ/mol) for the vaporization of benzene at 13 Celcius.

*April 29, 2013*

**Chemistry**

The following thermodynamic data was obtained for an unknown compound. Delta Hvap = 31.3 kj/mol and Delta S Vap= 79.7 kj/mol .Calculate the normal boiling point of this compound in Celcius.. Thank you!

*April 29, 2013*

**Chemistry**

Calculate the molar solubility of MgCO3 in a solution that already contains 1.7×10−3 M sodium carbonate. MgCO3 Ksp = 6.82 x 10-6 IMPORTANT NOTE: You must use the quadratic equation to solve this problem. (DrBob222- thank you so much for all your help!)

*April 26, 2013*

**Chemistry**

how did you get (that's 0.17M x 1/2 = 0.085M)

*April 24, 2013*

**Chemistry**

What is the ph at the equivalence point for a titration of 250 mL of 0.17M piperidine with 0.17 M nitric acid. (piperidine: Kb = 1.3 x 10-3)

*April 23, 2013*

**Chemistry**

Consider the titration of 41.2ml of 0.230 M HF with 0.220 M NaOH . Calculate the ph after the addition of 11.9ml of sodium hydroxide.(HF: Ka = 3.50 x 10-4) Please, I need step by step on on how to solve this type of problem. Thank you very much!

*April 23, 2013*

**Chemistry**

A 17.6ml sample of a monoprotic acid is titrated with 0.212M NaOH. If 69.2ml of base is required to reach the equivalence point, what is the concentration of the acid?

*April 19, 2013*

**social studies**

what wiped out most of the indigenous population of australia

*April 8, 2013*

**Physics**

Sammy Sosa

*March 19, 2013*

**Math**

There are 16 cubic boxes of erasers in a case. What are all the possible dimensions for a case of erasers ? please help need in 30 minutes or less so confused help please thanks

*March 10, 2013*

**math**

2 minutes because 8 divided by 4 = 2

*March 5, 2013*

**Chemistry**

what is the freezing point of 16.7g of LiCl in 136g of water, assuming complete dissociation for water kf= -1.86/mol

*February 26, 2013*

**Chemistry**

what is the freezing point of 16.7g of LiCl in 136g of water, assuming complete dissociation for water kf= -1.86/mol

*February 26, 2013*

**Chemistry**

what is the freezing point of 16.7g of LiCl in 136g of water, assuming complete dissociation for water kf= -1.86/mol

*February 26, 2013*

**Chemistry**

what is the freezing point of 16.7g of LiCl in 136g of water, assuming complete dissociation for water kf= -1.86/mol

*February 26, 2013*

**CSU**

what is the freezing point of 16.7g of LiCl in 136g of water, assuming complete dissociation for water kf= -1.86/mol

*February 26, 2013*

**Math-grade 4**

thank you ms. sue.my mom said the same thing.

*February 4, 2013*

**Math-grade 4**

I have 12 with a remainder of 3. my teacher wants us to round and estimate. please help! do I round it to 7 divided by 70?

*February 4, 2013*

**Math-grade 4**

what is the estimated quotient of 6 divided into 75?

*February 4, 2013*

**math**

I don't know

*January 28, 2013*

**math **

katie is 4 years younger than sylvia. let k represent katie's age and let s represent slyvia's age.

*January 22, 2013*

**algebra**

It's m-3

*January 9, 2013*

**MATHS**

Is there any reason why f(g)=g^2+3 why do we replace the x with g? Sorry steve im trying my hardest to understand this

*December 19, 2012*

**MATHS**

Thank you steve It says i need to find f(g), i got a different result for some reason help please! And also in the second part, how did you get g^-1 = (x-1)/2 Thank you steve x

*December 19, 2012*

**MATHS**

Critical help please. Level 3 maths algebraic methods is really hard. Q) Two functions f and g are defined by f:x (arrow) x^2 + 3 g:x (arrow) 2x+1 Find a) the function fg b) solve the equation f(x)=12g^-1(x) I need to show my working out, please help someone

*December 19, 2012*

**Algebra 1**

Which one is it? A or D?

*December 18, 2012*

**Maths**

If tom got 200 euro for his birthday. He spent 1.0 how much did he spend?

*December 6, 2012*

**English**

What type of poem is this ? We found his flag one bitter morning And knew our hopes had come to woe. We had come pursuing glory But ended freezing in the snow. 1. The stanza of the poem offers an example of (1 point) slant rhyme. end rhyme. perfect rhyme. * internal rhyme. I ...

*December 5, 2012*

**science**

your a poo

*October 24, 2012*

**Math**

Mrs. Yale wrote a number between 35 and 48 on her board. The sum of the digits is 7. What number did Mrs. Yale write on her board?

*October 23, 2012*

**Chemistry**

3.95x10^-22

*October 16, 2012*

**health**

is it A??

*October 5, 2012*

**English**

Yes, I know what similes and metaphors are. My question is where are their examples of similes and metaphors in the story?

*September 18, 2012*

**English**

In the story The Necklace written by Guy de Maupassant what are the examples of similes and metaphors?

*September 18, 2012*

**grammar**

Everyone knows that necessity is the mother of invention. The woman who invented disposable diapers was both a woman and an inventor. Marion Donovan invented the disposable diaper in 1950, she used a regular cloth diaper, lined it with pieces cut from a shower curtain, and ...

*September 10, 2012*

**ashworth**

i go to the same school for homeschooling and i need help with the same question

*July 8, 2012*

**Business law**

The state of Confusion enacted a statute requiring all trucks and towing trailers that use its highways to use a B-type truck hitch that is presently being manufactured by only one manufacturer, which is located in Confusion. The result of this statute is that any trucker who...

*June 27, 2012*

**chemistry **

a 3.00g sample of baking soda is heated and decomposes according to the reaction below. Calculate the theoretical yield in grams for each of the three products Na2Co3. H2O, CO2

*June 17, 2012*

**chemistry**

From the following Information, calculate the standard change of enthalpy for the combustion of coal. SHOW WORK AND BALANCED REACTION!!! Compound DeltaHf (kj/mol) Coal 0.0 Carbon dioxide -393.5 Water (l) -285.9 Oxygen 0.0

*June 12, 2012*

**chemistry**

From the following Information, calculate the standard change of enthalpy for the combustion of coal. SHOW WORK AND BALANCED REACTION!!! Compound DeltaHf (kj/mol) Coal 0.0 Carbon dioxide -393.5 Water (l) -285.9 Oxygen 0.0

*June 12, 2012*

**chemistry**

What is the molar solubility of Sr3(AsO4)2 and the concentration of Sr^+2 and AsO4^-3 in a saturated solution at 25C? the Ksp is 1.3 E -18. Show the balanced reaction.

*June 10, 2012*

**Math**

How would I prove: 2^n + 2^n = 2^(n+1) The question asks for correct formatting in giving proof however I don't recall learning this before. Any help would be appreciated!

*May 28, 2012*

**Math**

12. A particular power boat travelling at V0 km/h when its power is turned off it will have its speed V given by V(t) = V0 x 10^-0.18t where t is the time in seconds since the engine was turned off. If this boat was travelling at 50k/h before powering down, construct a table ...

*May 28, 2012*

**math**

THANK YOU MY GOD YOU SAVED MY LIFE

*March 21, 2012*

**Chemistry**

If 150.0 grams of iron at 95.0 degrees Celcius, is placed in an insulated container containing 500.0 grams of water at 25.0 degrees Celcius, and both are allowed to come to the same temperature, what will that temperature be? The specific heat of water is 4.18 J/g degrees ...

*February 22, 2012*

**Geometry**

i have the same question in my class too so thank you

*February 14, 2012*

**Physics **

A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of 8.15 m/s at an angle of 18.5o below the horizontal. It strikes the ground 3.30 s later. How far horizontally from the base of the building does the ball strike the ground? What ...

*February 7, 2012*

**physics**

Describe in detail an experiment to find out the half life of a radioactive material

*January 31, 2012*

**physics science**

Please can you help as I am stuck, Describe ib detail, how you would carry out an investigation to measure the density of a block of aluminium? Thankyou

*January 31, 2012*

**physics science**

Sorry can someone please so me how to do this thanks

*January 31, 2012*

**physics science**

Sorry I don't understand this I have do decribe in detail the investigation could you please give me some pointers on how to start Thanks again

*January 31, 2012*

**physics science**

Please can you help as I am stuck, Describe ib detail, how you would carry out an investigation to measure the density of a block of aluminium? Thankyou

*January 31, 2012*

**Math**

When you do a free throw, you get 2 tries 42/60=.7=7/10=70% probability(make) 10/10-7/10=3/10=30% probability (miss) 0 points= 3/10=30% 1 point= 7/10•3/10=21/100=21% 2 points= 7/10•7/10=49/100=49% To make sure it's in the range of 100 as the whole number add 3/10...

*December 14, 2011*

**Calc**

We are working on finding the intervals of convergence of power series in class. Why do we not have to test for the convergence of the endpoints for geometric series? They always seem to diverge. Is this a set rule when working with the geometric series for this type of problem?

*December 1, 2011*

**irish**

thank you they were very helpful and thank's again

*November 30, 2011*

**irish**

im sorry for being cheeky i just find this hard

*November 30, 2011*

**irish**

its not an assignment and i was only asking if anyone understood this im sorry ok

*November 30, 2011*

**irish**

25 sentences on how you WILL SPEND! a day either at the weekend or tomorrow, a school day, or any piece of writing in the future tense. in irish can you help with a couple of them please!

*November 30, 2011*

**health and social care**

can you tell me about the nature vs nurture debate please thankyou

*November 16, 2011*

**Maths**

In the spring, 80% of the sheep in a flock of sheep had lambs. of those sheep with lambs, 30% had one lamb, 40% had two lambs and the rest had 3 lambs. a total of 240 lambs were born. how many sheep are in the flock? you must show your working.

*November 7, 2011*

**science**

please help

*November 6, 2011*

**science**

preparation of copper sulphate crystals excess copper oxide is needed above a)how do you know the solid is in excess? b)how do you remove the excess? c)what colour is the solution? d)give the next to steps to make crystals?

*November 6, 2011*

**MATHS**

the 50p is a 50p piece it says in the book it is less than 50p (money)

*November 5, 2011*

**MATHS**

please help

*November 5, 2011*

**MATHS**

matt and ruba each have one coin. The total amount of money is less than 50p. work out the probability that exactly one of the coins is a 10p piece. assume that all possible coins are equally likely.

*November 5, 2011*

**maths**

please help as soon as possible

*November 4, 2011*

**maths**

matt and ruba each have one coin. The total amount of money is less than 50p. work out the probability that exactly one of the coins is a 10p piece. assume that all possible coins are equally likely. please can you explain i have to know how to do this

*November 4, 2011*

**CHEMISTRY**

Thank you

*November 2, 2011*

**CHEMISTRY**

thank you so is AL2O3 3 elements Ca(HCO3)2 4 elements

*November 2, 2011*

**CHEMISTRY**

please help

*November 2, 2011*

**CHEMISTRY**

how many elements in (NH4)2SO4

*November 2, 2011*

**chemistry ASAP**

name the following: H2SeO3 H2TeO2 PO3^3- HCLO4 Please explain how to find the names !!!!!

*October 31, 2011*

**Physics**

The conducting rod ab shown below makes frictionless contact with metal rails ca and db. The apparatus is in a uniform magnetic field of 0.855 T, perpendicular to the plane of the figure. The length L of the rod is 25 cm. (a) Find the magnitude of the emf induced in the rod ...

*October 19, 2011*

**Math**

How do I multiply 100,400,300,700 x 300,555,555

*October 12, 2011*

**math**

what is the total price of a sweatshirt that is priced at $48 and taxed at 6.5%?

*October 11, 2011*