Thursday

December 8, 2016
Total # Posts: 1,952

**chemistry**

I was thinking that if, for example, two different pressures were given, two different volumes were given, two different temperatures were given and only one mole, then you use P1V1/n1T1...etc to find the missing mole. But, if only one pressure, one volume, and one temperature...

*May 7, 2008*

**chemistry**

I know how to use the equations pv=nrt and P1xV1/n1xT1 = P2xV2/n2xT2, but I don't understand when to use them. I have a test tomorrow and I'm going over some word problems, but I can't figure out how decide which formula you need to use. Is there a specific way to ...

*May 7, 2008*

**Chemistry -- to Dr.Bob I need your help!!!**

how do you do this

*May 6, 2008*

**history, and your opinion**

The songs Lift Every Voice and Sing and America the Beautiful both have religious refernces in the first stanza. Our current national anthem, The Star Spangled Banner does not. Traditonally only the first stanza is sung at baseball games and events. I need to come up with ...

*May 5, 2008*

**Chemistry**

So, for KCl, using the graph... T.....mass KCl/100 mL 10....30 20....32 or 33 30....35 40....38 50....41 60....44 70....46 80....49 90....52 or 53 100...56

*May 5, 2008*

**Chemistry**

In the question above this one it says refer to a solubility chart, but my professor never taught us how to answer these questions while using a solubility chart so I have no idea what to do. I've tried going to his office hours for help, but he's only there when I ...

*May 5, 2008*

**Chemistry**

How many grams of KCl can you dissolve in 50. g of water at 70 degrees C?

*May 5, 2008*

**Chemistry**

Thank you, I made the change. My professor is very precise, so I'm glad you noticed that!

*May 2, 2008*

**Chemistry**

mols HCl = 0.750 M x 0.025 L = 0.0186 mol M = 0.0186 mol/0.500 L = 0.0372 the answer is 0.0372 mol/l

*May 2, 2008*

**Chemistry**

What is the concentration of a solution prepared by diluting 25.0 mL of HCl 0.750 mol/L to a final volume of 500. mL?

*May 2, 2008*

**Advanced Math**

Find the values of x for which the equation sin x = -1 is true 2 pi n pi/2 + 2 pi n pi + 2 pi n 3 pi/2 +2 pi n Can someone please help. I don't understand how to do this.

*May 1, 2008*

**chemistry**

If A is a non-polar chemical and B is a non-polar solvent, what type of solubility (high or low) would you expect between A and B? --Is it high solubility?

*April 29, 2008*

**Chemistry**

So, if I convert mmHg to atm I get .904 atm. When I plug that into the equation, the final answer is 67.1 L?

*April 22, 2008*

**Chemistry**

Okay... 1) 275 g NaCl ----> 4.71 mol NaCl 2) Next, 4.71 mol NaCl * 1Cl2/2 NaCl = 2.36 mol Cl 3) V= nRT/P v= (2.36 mol)(0.0821 L atm/K Mol)(313K)/687mmHg = 0.0883 L Final answer: v = 0.0883 L

*April 22, 2008*

**Chemistry**

Sodium reacts with chlorine gas according to the reaction:\ 2 Na (s) + Cl2 (g) ---> 2 NaCl (s) What volume of chlorine gas, measured at 687 mmHg and 313 K, is required to form 275 g of NaCl?

*April 22, 2008*

**Chemistry**

Is this correct? (755 mmHg)(400.0cm^3)/298 K = (P2)(50.0cm^3)/(358 k)

*April 21, 2008*

**Chemistry**

If a gas has a volume of 400.0 cm cubed at a pressure of 755 mmHg and a temperature of 25 degrees celsius, what would be its pressure (in atm) at 85 degrees celsius if the volume is reduced to 50.0 cm cubed?

*April 21, 2008*

**Chemistry**

A tank contains 0.450 kg of oxygen(O2) compressed into a volume of 2.32 L. Estimate the gas pressure (in atm) inside the tank at 5 degrees celsius. Do I convert 0.450 kg from grams to moles, and if I do, do I use the molar mass of oxygen?

*April 19, 2008*

**Chemistry**

Convert 125000 Pa to psi

*April 18, 2008*

**chemistry**

A tank contains 0.450 kg of oxygen(O2) compressed into a volume of 2.32 L. Estimate the gas pressure (in atm) inside the tank at 5 degrees celsius.

*April 17, 2008*

**chemistry**

1) Convert 0.525 atm to kPa 2) Convert 125000 Pa to psi

*April 17, 2008*

**Chemistry**

I'm having a hard time figuring these out. Please help me on them! For the reaction Fe2O3 + 3 Co = 2 Fe + 3 CO2: a) how many moles of Fe can be produced from 75 moles Co? b) how many moles of CO2 can be produced from 15 moles of Fe2O3? c) what is the maximum amount (in ...

*April 9, 2008*

**english**

what are values and attitudes?

*April 3, 2008*

**Chemistry**

Hydrogren, a possible future fuel, can also be obtained from other compounds such as ethanol. Ethanol can be made from the fermentation of crops, such as corn. How much hydrogen in grams can be obtained from 1.0 kg of ethanol (C2H5OH)?

*April 1, 2008*

**Chemistry**

The rock in a lead ore deposit contains 84% PbS by mass. How many kilograms of the rock must be processed to obtain 1.0 kg of Pb?

*April 1, 2008*

**chemistry**

How many butane molecules are present in a sample that contains 5.0 moles of butane? (Butane- C4H10) What would be the mass of 75 moles of butane?

*March 26, 2008*

**Math**

Use the counting principle to determine the number of different arrangements of bicycles that are possible.

*March 25, 2008*

**Math**

Two balls are to be selected without replacement from a bag containing one red, one blue, one green, one yellow, and one black ball. How many points are there in the sample space?

*March 25, 2008*

**Math**

Why is ounces abbreviated with oz.?

*March 19, 2008*

**SCIENCE**

HOW MANY PEOPLE DOES IT TAKE TO BUILD A GREEN ROOF?

*March 14, 2008*

**chem**

what do the coefficents in a balanced equation mean?

*March 12, 2008*

**chemistry**

I have two questions. 1. How do I predict the formula of ionic compounds when one is a polyatomic ion? Example: Al (+3) and SO4(-2). 2. How would I obtain the charge of Hg in the formula HgCl2?

*March 7, 2008*

**chemistry**

72.4/97.82*100?

*March 7, 2008*

**chemistry**

Determine the percent yield for the reaction between 98.7g of Sb2S3 and excess oxygen gas if 72.4g Sb4O6 is recovered along with an unknown amount of sulfur dioxide gas.

*March 7, 2008*

**Writing**

I need a sentence with the words "loose" and "folklore"? Help?

*March 3, 2008*

**advanced algebra**

we are working with logarithms and i don't understand them at all! I get the basic content but then it gets a little more advanced, and I get completely confused. There's one in particular that I have NO idea how to do. Help please?! Simplify: 3 ^ [log(base 9)2 + log(...

*February 24, 2008*

**chemistry**

Classify each of the following mixtures as homogeneous or heterogeneous: 1. Shampoo 2. Vegetable Oil

*February 19, 2008*

**math**

The top of a 15-foot ladder is 3 ft. father up a wall than the foot of the ladder is from the bottom of the wall. How far is the foot of the ladder from the bottom of the wall?

*February 17, 2008*

**french**

faites deux phrases avec chacun de ces verbes au passe compose,au future proche et au future simple

*February 16, 2008*

**accounting**

External users are existing or potential investors, creditors, analysts, financial advisers, regulatory authorities, unions, and the general public.

*February 15, 2008*

**chemistry**

A backpacker carries 2.5 L of white gas as fuel for her stove. How many pounds does the fuel add to her load? Assume the density of white gas to be 0.79 g/cm^3.

*February 14, 2008*

**English**

I do believe that yes, the answer is A.

*February 12, 2008*

**grade 11 math**

expand/explain? how did you get -1? the answer is positive, not negative. hmm..

*February 12, 2008*

**grade 11 math**

x/6-5=1/2x+1/3x-4 AHH! help. i need step-by-step. all i know is that the answer is x=1.5 Thanks!

*February 12, 2008*

**precalc**

the graph of a cubic function has a local min at (5,-3) and a point of symmetry at (0,4). At what point does a local maximum occur? i don't quite know how to figure this one out, any help?

*February 11, 2008*

**research paper**

I am writing a research paper. The corrlation between interest rates and credit card usage. I cant find many websites on this do you know of any?

*January 31, 2008*

**pre calc**

solve each inequality: (x-4)(x-2)^2(x-3)^2 < 0

*January 28, 2008*

**lit( essay)**

its a great story. its not an essay.

*January 28, 2008*

**pre calc**

The publisher of a magazine that has a circulation of 80,000 and sells for 1.6 a copy decides to raise the price due to distribution costs. By surveying the readers the publisher finds that the magazine will lose 10,000 readers for every .4 increase in price. What price per ...

*January 21, 2008*

**pre calc**

Thank you so much for the help

*January 20, 2008*

**pre calc**

suppose you have 102m of fencing to make two side by side rectangles, making one large rectangle when put together. What is the maxium area that you can enclose?

*January 20, 2008*

**physics**

How did you get the angle?

*January 1, 2008*

**Math**

Henry bought a new dishwasher for $320. He paid $20 down and made 10 monthly payments of $34. What actual yearly interest did Henry pay? 1 - 14.55 2 - 29.09 3 - 34.38 4 - 68.75

*December 14, 2007*

**Math**

Thanks!!

*December 13, 2007*

**Math**

The decimal form 1.46 becomes ______ expressed as a percent. 1- .146% 2- 1.46% 3- 14.6% 4- 146% 1.46 x 100 = 146% is this correct?

*December 13, 2007*

**Math**

Thank you for breaking this down for me!!

*December 13, 2007*

**Math**

What is the product of 7/16, 4/3 and 1/2?

*December 13, 2007*

**English**

Sorry I get confuse, the text is this: Chinese new year Chinese people celebrate new year in the first new moon of Febraury,it changes every year, it takes two weeks, from the new moon to the full moon, people wear red clothes in new year, they bring good luck in the future. ...

*November 21, 2007*

**english**

Is this text correct? Chinese new year The chinese people celebrate new years eve in the first new moon of Febraury,it changes every year, it takes two weeks, from the new moon to the full moon, people wear red clothes in new year, they bring good luck in the future. They ...

*November 21, 2007*

**algebra**

what does it mean to solve and check for extraneous solutions for sqry+9=1

*November 20, 2007*

**algebra**

i need help to simplify with positive exponents only. (b^2)^-6/b^-4

*November 19, 2007*

**algebra**

Solve by factoring x^2 plus 8x ,minus 20 equal 0

*November 18, 2007*

**algebra**

can someone tell me if i did the problem correct (solve by completing the square) 4x^2+2x-3=0 x^2+(1/2)=3/4 x^2+(1/2)+(1/4)^2=3/4+(1/4)^2 (x+1/4)^2=13/16 x+1/4=+-sqrt 13/16 x+1/4=+-sqrt 13/4 x=-1/4+-sqrt 13/4 x=-1+-sqrt 13/4

*November 18, 2007*

**i need help..algebra/math**

solve by using the quadratic formula: x2 plus x minus 2 equal 0 I know the formula is a=1 b=1 c=2 I'm having trouble solving...please help.

*November 16, 2007*

*****repost algebra.math**

So am im posting the graph with 2.5 and -3.25?

*November 14, 2007*

**algebra.math**

i need serious help, I'm trying to plot table of values for sketching graph (parabola)for y=x^2-5x+3 xy values are 0,3 1,-1 2.5,-3.25 3,-3 4,-1 5,3 6,9 are these values correct, I'm having problems graphing.

*November 14, 2007*

**Log problem**

no i put it exactly how the paper has it log^1/8) and then it has x=-1 I do not understand how to do it at all.

*November 14, 2007*

**Log problems**

Solve log(1/8) x=-1 Can some explain how to do this along with the answer.

*November 14, 2007*

**AP CHEMISTRY**

If a Li 2+ ion, initially in the 2nd excited state absorbs a photon of light with a fequency of 2.82 X 10^6 GHz, what will be the final energy level for this electron? Show all stepts to get final energy level. i have no clue what this question is even asking :[?

*November 7, 2007*

**CHEMISTRY**

If a Li 2+ ion, initially in the 2nd excited state absorbs a photon of light with a fequency of 2.82 X 10^6 GHz, what will be the final energy level for this electron? Show all stepts to get final energy level. i have no clue what this question is even asking :[?

*November 7, 2007*

**Algebra 2**

Yeah i meant -x^4

*November 6, 2007*

**Algebra 2**

I know how to graph points but I need the points to this equation. f(x)=(-x)^4+4x^2-2x solve by making a table of values. It says I also need the coordinates at which the relative maxima and minima occur.

*November 6, 2007*

**Chemistry**

Part 2 Secure the stand and two clean burets. Using the funnel, fill one buret to the 0 mark with HCl. Rinse out the funnel thoroughly and carefully fill the other buret to the 0 mark with 2 M NaOH solution. Drain 25 mL of NaOH solution into the calorimeter. Record the mass of...

*October 24, 2007*

**Chemistry**

Begin by measuring the mass of the empty calorimeter and record the value. Next, add approximately 1-1.5 g of solid NaOH pellets and record the mass. Carefully grind up the pellets using a mortar and pestle. Then, transfer the ground up NaOH into the calorimeter and measure ...

*October 24, 2007*

**Chemistry**

What improvements could i make to this lab? so far i only have that the graduated cylinder should be changed to a buret for a more accurate measurement. Procedure: Part 1 Begin by measuring the mass of the empty calorimeter and record the value. Next, add approximately 1-1.5 g...

*October 24, 2007*

**Algebra 2 -math**

When you cry over spilt milk

*October 24, 2007*

**physics**

Mere and Ruth investigated the relationship between the applied force, F, and the extension, x of a spring. The results they obtained are shown in the table below. Force, F (N) Extension, x (m) 0.0 0.0 2.0 0.033 4.0 0.066 6.0 0.099 8.0 0.132 10.0 0.165 Draw a graph of force ...

*October 17, 2007*

**Physics**

Mere and Ruth investigated the relationship between the applied force, F, and the extension, x of a spring. The results they obtained are shown in the table below. Force F (N) Extension x (M) 0.0 0.0 2.0 0.033 4.0 0.066 6.0 0.099 8.0 0.132 10.0 0.165 state the type of ...

*October 17, 2007*

**problem stats**

an instant lottery game gives you probability .02 of winning on any one play. Plays are indpendent of each other. If you play 5 times, what is the probability that you win at least once.

*October 15, 2007*

**ap algebra**

Please help me with this problem. I don't know what to do. Use the graph or table to determine a solution of the equation. Use synthetic division to verify that this number is a solution of the equation. Then solve the polynomial equation. x3 + 6x2 + 11x + 6 = 0

*October 15, 2007*

**problem stats**

an instant lottery game gives you probability .02 of winning on any one play. Plays are indpendent of each other. If you play 5 times, what is the probability that you win at least once.

*October 15, 2007*

**chemistry**

what is the trend in bond length for o-h (.96A), s-h (1.341A) and n-h (1.005A). Explain the trend- do the calculated bond distances match the expected trend?

*October 11, 2007*

**Variation-Questions**

If A varies directly as B, and A =7 when B =2. Find B when A =21

*October 8, 2007*

**biology**

found by me on some website: 'five basic things to survive; food, water, fuel (for cooking and heating), clothing, and shelter. ' Lol i'd never said that it was fuel....

*October 8, 2007*

**English**

OMG i've made a mistake while typing: The question should be: The Beatles recorded together until 1970.

*October 8, 2007*

**English**

Hi there. I'm from Poland and I'm studying English. I need some help with a True/False exercise. There's a piece of text and there's a question below it and you need to answer it with true or false. My query is especially aimed at English Teacher's and ...

*October 8, 2007*

**AP CHEMISTRY**

Could you please look over my work and see if I did this correctly? Thanks When 3.200 g of liquid ethyl alcohol (C2H5OH) is burned in a bomb calorimeter containing 3.500 kg of water, the temp rises from 22.84 degrees C to 28.36 degrees C. The calorimeter constant is 25550 J/ ...

*October 7, 2007*

**CHEM**

Could you please look over my work and see if I did this correctly? Thanks When 3.200 g of liquid ethyl alcohol (C2H5OH) is burned in a bomb calorimeter containing 3.500 kg of water, the temp rises from 22.84 degrees C to 28.36 degrees C. The calorimeter constant is 25550 J/ ...

*October 7, 2007*

**MATH**

HOW MANY FOUR-LETTER CODE WORDS CAN BR FORMED USING A STANDARD 26-LETTER ALPHABET IF REPETITION IS ALLOWED IF REPETITION IS NOT ALLOWED

*October 4, 2007*

**MATH**

HOW MANY DIFFERENT ARRANGEMENTS ARE THERE OF THE LETTERS IN TESTERS?

*October 4, 2007*

**algebra**

can someone tell me if this problem is correct: Determine whether each of the following trinomials is perfect square. If it is factor the trinomial: x^2-24x+48 =(-24)^2-4(48)

*October 2, 2007*

**biology**

can you provide an explanation on how a "muscle tone" reflex happens?

*October 1, 2007*

**biology**

can you provide a simple explanation of how a cell fires or synapses

*October 1, 2007*

**Science (big idea of energy)**

Well when magnesium burns it makes a realy big flsh which can realy hurt your eyes if you look at it

*October 1, 2007*

**algebra question**

the sum of two numbers is 240 the larger number is 6 less than twice the smaller. what are the two number.

*October 1, 2007*

**AP CHEMISTRY**

A 2.75 g sample of the hydrocarbon acetone, CH3COCH3, is burned in a bomb calorimeter with 975 mL of water, initially at 23.50 degrees celsius. The bomb is constructed of 285.0 g of nickel metal having a specific heat capacity of Cp = 0.826 J/ g degrees C. The final ...

*September 30, 2007*

**Psychology**

Well there's serotonin, acetylcholine, norepinephrine and dopamine... An excess of dopamine is usually associated with schizophrenia. Serotonin and norepinephrine can be associated with depression. Norepinephrine is prevalent in the sympathetic nervous system, and when ...

*September 30, 2007*

**AP Chemistry**

A 2.75 g sample of the hydrocarbon acetone, CH3COCH3, is burned in a bomb calorimeter with 975 mL of water, initially at 23.50 degrees celsius. The bomb is constructed of 285.0 g of nickel metal having a specific heat capacity of Cp = 0.826 J/ g degrees C. The final ...

*September 30, 2007*

**Chemistry**

A 2.75 g sample of the hydrocarbon acetone, CH3COCH3, is burned in a bomb calorimeter with 975 mL of water, initially at 23.50 degrees celsius. The bomb is constructed of 285.0 g of nickel metal having a specific heat capacity of Cp = 0.826 J/ g degrees C. The final ...

*September 30, 2007*