Friday

January 30, 2015

January 30, 2015

Total # Posts: 790

**Math**

A chemistry teacher needs 2.5 liters of a sulfuric acid solution that is 20% sulfuric acid and 80% water . He has 2 liters of a 15% sulfuric acid solutionleft over from earlier laboratory exercises. He also has 44 liters of a 50% solution. Let x represent the number of liters ...
*May 31, 2011*

**Math**

correct
*May 30, 2011*

**math**

the volume of a container that is 8" long 4" long and3' high is _cu in. plaese help
*May 29, 2011*

**math**

a 22" diameter circle has an area of_sq in.
*May 29, 2011*

**math**

dy/dx=2/27(x-3)√((x^2-6x+23)/y)
*May 23, 2011*

**Physics**

Find the fg y component because that is equal to the "n" in the equation: F(static friction) = mu x n
*May 21, 2011*

**calculus**

Hello drwls. Please can you explain how you get 72sqrt2+c. Surely, if it is 50.911=50.911+c, if one subtracts either side c=0? Am I missing something?Thank you for your help.
*May 20, 2011*

**calculus**

Please help. I have an implicit answer to a differential equation of 18y*sqrt(y)=(2(x^2-6x+23)^3/2)/3 plus arbitrary constant. What is the particular solution to this for which y=2 when x=1. And then express this particular solution answer in an explicit form. Please help and ...
*May 20, 2011*

**calculus**

Please help. How do I seperate the variables in the following differential equation dy/dx=(2/27)(x-3)then square root (x^2-6x+23)/y where (y>0). Then give general solution in implicit form. Thank you so much if you can help.
*May 19, 2011*

**litres and millilitres**

1/10L=ml
*May 11, 2011*

**Math**

Solve for x. 3^(2x)-2*3^(x+5)+3^10= 0
*May 2, 2011*

**calculus**

let R be the region bounded by the x-axis, the graph of y=sqrt(x+1), and the line x=3. Find the area of the region R
*May 1, 2011*

**Science/Math**

We have 30 grams of clay. We understand that Density=Mass/Volume. We understand that the Density of water is 1.0 and in order for the clay boat to float in the water Density needs to be less than 1.0. So my question is using 30 grams of clay what design will allow me to hold ...
*April 24, 2011*

**chemistry**

Is it possible to calculate the value of the solubility product constant without being given any concentrations?
*April 23, 2011*

**Compound math**

$24,000 is invested for 5 years with APR of 2% in daily compounding.What is the balance in account after 5 years?
*April 19, 2011*

**business**

How did U.S. manufacturers become vulnerable to offshore outsourcing? Give examples to support your answers.
*April 9, 2011*

**Chemistry**

Write a net ionic equation and calculate K for the reaction in aq between acidic acid and sodium hydroxide. Given Ka (acidic acid) = 1.8 x 10^-5
*April 4, 2011*

**social studies**

Ads that rely on the testimonials of people who have used the product are using what technique?
*April 4, 2011*

**Science**

Hello van some one show me how to draw a dot and cross diagramm for 1 lithium atom and 1 fluorine atom(Lif) and also a diagram for 1 magnesium atom and 1 oxygen atom (MgO) Thankyou Paul.
*March 28, 2011*

**chemistry**

What is the molarity of Cl− ions at the stoi- chiometric point? Answer in units of mol/L.
*March 26, 2011*

**chemistry**

How do I calculate 50ml of a 50mM sodium momophosphate buffer solution
*March 23, 2011*

**Chemistry**

The maximum solubility of silver sulfate, Ag2SO4 [molar mass = 312], is 4.50 g/L at 25°C. Silver sulfate dissociates by the reaction below: Ag2SO4(s) <--> 2 Ag+ (aq)+ SO4¯² (aq) 1.What are the [Ag+] and [SO4¯²] in a saturated solution of silver ...
*March 20, 2011*

**Trigonometry**

Can you verify this identity? cos(4x)cos(2x)= (1/2)[cos8x+cos2x]
*March 14, 2011*

**Math**

Oh, I think I got it. Are the answers (-15,18) and (1,2)?
*March 13, 2011*

**Math**

At what points does the line y+x-3=0 intersect the curve 2y=6x+2(x^2)-(y^2)?
*March 13, 2011*

**Physics**

thank you so much!
*March 9, 2011*

**Physics**

I am a little confused about kinetic and potential energy regarding roller coasters. I understand that the first hill has to be the highest to gain the potential energy (PE). I hope someone can help with this example I just made up to help me understand: 1st Hill: 50 m from ...
*March 9, 2011*

**Chemistry**

A student titrates 0.100M KOH into 50.00 ml of weak acid HX. The pH of the solution is 4.25 after 20.00 ml of the base has been added, and equivalence point is reached when 40.00 ml of the base is added. 1. What is the concentration of the acid, HX ? 2. What is the Ka value of...
*March 9, 2011*

**Physics**

A bus starts from rest at a bus stop and accelerates at a rate of 1.12 m/s^2 for 11.0s. It runs at constant speed for 80.0 s and slows at a rate 1.20 m/s^2 until it stops at the next bus stop. (a) What is the maximum speed attained. (b) Find the total distance covered.
*March 8, 2011*

**math**

Rail earns 10% commission on each guitar and 15% commission on each keyboard he sells. In two week he sold 5 guitars that cost$260 each and 2 keyboards that costv$420 each. How much commission did he earn on these seven items?
*March 3, 2011*

**gr. 12 biology**

My teacher wants me to calculate the rate of enzyme activity (1/s) I'm given the temperatures: 0 , 15, 30, ,50, and 80 (degrees celsius) AND the times 8.74, 18.83, 14.30, 34.22, and infinity respectively (seconds obviously, these are the times it took the enzyme to react...
*February 27, 2011*

**gr. 12 biology**

My teacher wants me to calculate the rate of enzyme activity (1/s) I'm given the temperatures: 0 , 15, 30, ,50, and 80 (degrees celsius) AND the times 8.74, 18.83, 14.30, 34.22, and infinity respectively (seconds obviously, these are the times it took the enzyme to react...
*February 27, 2011*

**Math**

Suppose that y≤5x,3x≤y and 14x+15y≤1 together with 0≤x, 0≤y. The maximum value of the function y+x on the resulting region occurs at x=? and y=? The maximum value of the function is ?
*February 26, 2011*

**physic**

If the work required to speed up a car from 13 km/h to 20 km/h is 6.5×103 J, what would be the work required to increase the car’s speed from 20 km/h to 35 km/h?
*February 23, 2011*

**Physics**

I can't figure this question out. If there are three weights attached to the corners of an equilateral triangle with side length 10 cm Measured from the bottom left corner, what is the center of mass of this object if M1 = 0.1 kg, M2 = 0.2 kg, and M3 = 0.3 kg?
*February 22, 2011*

**Chem**

What is the pressure in a 2.00 L container which holds 0.100 mol of methane and and 0.200 mol of carbon dioxide at standard temperature?
*February 17, 2011*

**Physics**

Calculate the magnitude of the potential difference between points a and b in the figure if R1=2.36 Ù, R2=4.29 Ù,and R3=10.08 Ù.
*February 17, 2011*

**Chemistry**

What is the pressure in a 2.00 L container which holds 0.100 mol of methane and and 0.200 mol of carbon dioxide at standard temperature?
*February 17, 2011*

**Chemistry- Drbob-help#3**

Thanks I understand now what I did wrong you have been a big help.
*February 10, 2011*

**Chemistry- Drbob-help#3**

I still need help with #3 I'm not sure how I got 1.14M. I have tried to do the problem over, but I not coming up with my original answer of 1.14M. Somehow I am missing a step. Please show work for the 1.14M Thanks Question#9 reads exactly as written. A student makes a ...
*February 10, 2011*

**Chemistry- Drbob-help**

I have placed the answer I got please help. A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 870mL 2. Calculate the % ...
*February 9, 2011*

**chemistry**

How much NH3 can be produce from 20 liter 32,5 wt%(NH2)2CO (urea) aqueous solution. The reaction path way is : (NH2)2CO +H2O= 2NH3+ CO2 Thanx
*February 9, 2011*

**Chemistry**

A student dissolves 18.9 grams of Zn(NO3)2 [molar mass = 189] in enough water to make 500.0 of solution. A 100.0 ml portion of this solution is diluted to 1000.0 ml.What is the [NO3¯ ] in the second solution? A) 0.0100M B) 0.0200M C) 0.0300M D) 0.0400M E) 0.0500M
*February 9, 2011*

**Chemistry**

A student dissolves 18.9 grams of Zn(NO3)2 [molar mass = 189] in enough water to make 500.0 of solution. A 100.0 ml portion of this solution is diluted to 1000.0 ml.What is the [NO3¯ ] in the second solution? A) 0.0100M B) 0.0200M C) 0.0300M D) 0.0400M E) 0.0500M
*February 8, 2011*

**Math**

The reduced row echelon form of the matrix -1/2 1/2 3/2 -3/2 2 3/2 1/2 -3/2 9/2 is?
*February 6, 2011*

**Math**

The reduced row echelon form of the matrix -1/2 1/2 3/2 -3/2 2 3/2 1/2 -3/2 9/2 is?
*February 5, 2011*

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...
*February 1, 2011*

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...
*February 1, 2011*

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...
*January 31, 2011*

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...
*January 31, 2011*

**Chemistry**

what volume of 1.015mol/L magnesium hydroxide is needed to neutralize 40.0mL of 1.60mol/L hydrochloric acid. Can you work it out please? Thanks!
*January 27, 2011*

**Chemistry**

what volume of 1.015mol/L magnesium hydroxide is needed to neutralize 40.0mL of 1.60mol/L hydrochloric acid. Can you work it out please? Thanks!
*January 27, 2011*

**Chemistry**

8.76g of aluminum sulphide is added to 0.0350L of 0.250mol/L lead(II)nitrate solution. calculate the maximum mass of precipitate, PbS that can form
*January 27, 2011*

**Chemistry**

The following data is collected for the decomposition of methy isonitrile at various tempertures: Temp.(C)---{k(/s)} --- lnk---1/T 290--- {2.52*10^-5}--- ?--- ? 299--- {5.25*10^-5}--- ? --- ? 330--- {6.30*10^-4}--- ?--- ? Complete the table above and, using your graphing ...
*January 26, 2011*

**Chemistry**

The following data is collected for the decomposition of methy isonitrile at various tempertures: Temp.(C)---{k(/s)} --- lnk---1/T 290--- {2.52*10^-5}--- ?--- ? 299--- {5.25*10^-5}--- ? --- ? 330--- {6.30*10^-4}--- ?--- ? Complete the table above and, using your graphing ...
*January 26, 2011*

**Chemistry**

The following data is collected for the decomposition of methy isonitrile at various tempertures: Temp.(C) k(/s) lnk 1/T 290--- 2.52*10^-5 ? ? 299--- 5.25*10^-5 ? ? 330--- 6.30*10^-4 ? ? Complete the table above and, using your graphing calculator determine the value of the ...
*January 24, 2011*

**Chemistry**

NH4HS(s )<=>NH3(g)+ H2S(g) ∆H = +93 kilojoues The equilibrium,above is established by placing solid NH4HS in an evacuated container at 25degreesC. At equilibrium, some solid NH4HS remains in the container. Predict and explain the following. The effect on the ...
*January 14, 2011*

**Chemistry**

NH4HS(s) NH3(g) + H2S(g) ∆H_ = +93 kilojoules The equilibrium above is established by placing solid NH4HS in an evacuated container at 25°C. At equilibrium, some solid NH4HS remains in the container. Predict and explain each of the following. (a) The effect on the ...
*January 13, 2011*

**microeconomics**

1. Why might a profitable motel shut down in the long run if the land on which it is located becomes extremely valuable due to surrounding economic development? 1a. What kinds of costs are involved in making a decision to shut down?
*January 12, 2011*

**chem**

what are the normal freezing points and boiling points of the following solutions: a. 21.1g NaCl in 135mL of water b. 15.4g urea in 66.7 mL water?
*January 12, 2011*

**chem**

what are the normal freezing points and boiling points of the following solutions: a. 21.1g NaCl in 135mL of water b. 15.4g urea in 66.7 mL water?
*January 12, 2011*

**math**

A dice is 4cm in all sides. What if you enlarge it by 1/4. What will be the size of all its size in cm3??
*January 8, 2011*

**Science (Energy)**

Ok i have done 2 experiments (See below) the question i need help with is i need to explain the difference for the two combustions and i just dont know, please help me and thankyou for your help. The Combustion Of Marshmallows Aim To investigate how much energy is transferred ...
*December 17, 2010*

**physics **

How much paraffin oil would be needed to heat the same volume of water? • Heat capacity of water = 4200 j kg-1 K-1 • Mass of 1 litre of water = 1kg • Heat value of paraffin = 45M J kg-1 • Density of paraffin = 800kg m -3 • 1 cubic centimetre (1cm3 = 10...
*December 15, 2010*

**Physics **

How long would it take a kettle with a 1kW heating element to heat 1 litre of water? Watts = Joules / second • Mass of 1 litre of water = 1kg • 1 kW = 1 k Joule / second or 1000 joules/ second • 1g of water needs 4.184J to raise the temperature by 1̊ c. &#...
*December 15, 2010*

**reading**

Tell me about the bokk Eragon
*December 14, 2010*

**Chemstry**

A 5.00 gram mixture of CaO and CaCO3 is heated strongly. After heating, the mixture has a mass of 4.00 grams. What % of the original mixture is CaCO3?
*December 13, 2010*

**Chemistry**

A 5.00 gram mixture of CaO and CaO3 is heated strongly. After heating, the mixture it has a mass of 4.00 grams. What % of the original mixture is CaCo3?
*December 9, 2010*

**science**

can anyone give me 10 examples or energy interconversions and how they work please thankyou.
*December 5, 2010*

**science**

can anyone give me examples of energy intercoversions please
*December 5, 2010*

**math**

5-16/3=
*December 2, 2010*

**Math-3rd grade**

Round to estimate the sum of all the numbers in 14.
*December 1, 2010*

**4th grade**

$10
*December 1, 2010*

**chem class**

You did an extra step of 14-8.4. pH= -log[H+] -log[3.98x10^-9] = 8.400 pH=8.400
*November 21, 2010*

**Physics**

720kg
*November 21, 2010*

**mis**

Choose one of the following basic business processes: inventory management, operations and manufacturing, HR management, or accounting/financial management. Use the Internet to identify three vendors that license a product to support that process. Compare offerings from the ...
*November 19, 2010*

**Writing**

What type of tone would be appropriate for an informal report?
*November 18, 2010*

**algebra**

thanks just new way of putting it thansk
*November 17, 2010*

**algebra**

it says find the roots of each equation by factoring x^2+8x=-16
*November 17, 2010*

**Math**

this equation is writing as ax^2+bx+c you need to find x. the equation for x is x=b/2a plug it in b=24 a=4 x=24/2x4=24/8=3 if x = 3 plug it in to your equation 4(3)^2+24(3)+39 4x9+72+39 36+72+39=147 so the vertex is (3,147) because a is 24 its positive meaning it opens up ...
*November 17, 2010*

**science**

What other applications can be used with MS Excel to exchange information and data?
*November 16, 2010*

**algebra**

Y= 7 7=3(9)+b m=3 7=27+b x=9 27 27 b=-20 -20=b y=3x-20
*November 16, 2010*

**CALCULUS BC**

a particle moves on the x-axis in such a way that its position at time t is given by x(t)=3t^5-25^3+60t. for what values of t is the particle moving to the left. a.-2<t<1 only b.-2<t<-1 and 1<t<2 c.1<t<2 only d.-1<t<1 and t>2 e.t<-2,-1<t&...
*November 15, 2010*

**AP PHYSICS**

the height of the upper falls at Yellowstone falls is 33.2m. when the water reaches the botton of the falls, its speed is 25.8 m/s. neglecting air resistance, what is the speed of the water at the to of te falls.
*November 15, 2010*

**math - algebra**

how would i solve this using the substitution method 3y=11-x 3x-y=3 thanks
*November 14, 2010*

**physics**

A girl 36 kg occupies a seat of a swing that this subject by two chains 20 m in length each. If someone drops the girl from an 8 m position below the highest of the swing. What strength exercises it on the girl when she passes through the point lower?
*November 10, 2010*

**physics**

A girl 36 kg occupies a seat of a swing that this subject by two chains 20 m in length each. If someone drops the girl from an 8 m position below the highest of the swing. What strength exercises it on the girl when she passes through the point lower?
*November 10, 2010*

**Science**

I conducted an experiment of the heat of combustion for three alcohol fuels, methyl, propyl and ethyl. The results were: Methyl - mass before was 231.81g temp of water before heating was 15 deg c. temp of water after heating was 40 deg c. mass of methyl after heating 229.92g ...
*November 8, 2010*

**Business**

How can knowledge of the direct and indirect approaches help writers write “efficiently and effectively”?
*November 5, 2010*

**math**

yeah 421 too
*November 4, 2010*

**math**

if a 1 block means ones 10 block means tens and 100 block means 100s then the number would be 842 because 8 is 2 times as much as 4 and 4 is 2 times as much as 2
*November 4, 2010*

**math**

x=?
*November 3, 2010*

**math**

just do the problum backwards if you have the answer to the square root what you do is square that number ^5x=5 5x5= 25 ^25=5 so now that you have the number being square rooted all you have to do is find our the answer to this equation 5x?=25
*November 3, 2010*

**math **

a ratio is 60:120 one way i remember this is by saying it 60 TO 120 when you say a ratio you say to and when you use a fraction you say by.
*November 3, 2010*

**5th grade**

sorry that didint work well
*November 3, 2010*

**5th grade**

ok so your parallegram looks like this 5 l----\ 4l-----\ 7 so you know that the bottom line has 2 more meters then the top so what you do is you cut that off from the shape and think of it as a 5x4 rectangle 5 ______ [\ 4 [ ] 4[ \ [ ] [__\ ------ 2 4x5=20 4x2=8 8/2=4 find the ...
*November 3, 2010*

**math**

yes
*November 3, 2010*

**5th grade**

its hard to exsplane without signs google long division
*November 3, 2010*

**math**

i think your asking what the odds are that you will pick a odd number if picked from 36 cards numbered 1-36 if so 1 is pime 2 is prime 3 is prim 5 is prime 7 is prime 11 is prime 13 is prime 17 is prime 19 is prime 23 is prime 29 is prime 31 is prime and thats it so that means...
*November 3, 2010*

Pages: <<Prev | 1 | 2 | 3 | 4 | **5** | 6 | 7 | 8 | Next>>