# Posts by David

Total # Posts: 2,249

**math**

78*43+1=3355

*April 28, 2010*

**Chemistry**

An aqueous solution of a compound with a very high molar mass was prepared in a concentration of 82.7 g·L-1 at 25 °C. Its osmotic pressure was 0.540 ·102 Pa. Calculate the molar mass of the compound. Cheers

*April 28, 2010*

**6th grade math**

2 ---- t = 9 5

*April 26, 2010*

**Math**

At the National Zoo, 12 out of 25 exhibits contain a mammal. Assuming that there are 375 exhibits, how many many are mammals? A) 11 B) 32 C) 132 D) 300 Here is what I am doing: 12/25 = x/375 375 * (12/25) = (x/375) * 375 180 = x But 180 isn't an option

*April 26, 2010*

**6th Grade Science**

How do meteorologists forecast weather?

*April 24, 2010*

**6th Grade Grammar**

Also, is got a verb?

*April 21, 2010*

**6th Grade Grammar**

What is the positive adverb form? ______ , more , most and ______ , less , least

*April 21, 2010*

**6th Grade Math**

Thank you!

*April 21, 2010*

**6th Grade Math**

This is fractions. Not dividing problems. (Ex: 3/5 is a fraction) 5c = 2/3 (divided by) 2/3

*April 21, 2010*

**Physics**

You swing one yo-yo around your head in a horizontal circle. Then you swing another yo-yo with twice the mass of the first one, but you don't change the length of the string or the period. How do the tensions in the strings differ?

*April 21, 2010*

**Finance**

Adams Enterprises’ noncallable bonds currently sell for $1,120. They have a 15- year maturity, an annual coupon of $85, and a par value of $1,000. What is their yield to maturity?

*April 21, 2010*

**6th grade math HELP**

I need help with definding classify

*April 18, 2010*

**MATH**

A set of numbers has “the triple-sum property” (or TSP) if there exist three numbers in the set whose sum is also in the set. [Repetitions are allowed.] For example, the set U = {2, 3, 7} has TSP since 2 + 2 + 3 = 7, while V = {2, 3, 10} fails to have TSP. (a) ...

*April 15, 2010*

**social studies**

life, liberty and the pursuit of happiness.

*April 14, 2010*

**chemistry**

Trimellitic acid containing carbon, hydrogen, and oxygen has 51.44% C, 2.88% H, and 45.68% O. It can be obtained by oxidation of coal with nitric acid. A 2.416-g sample of this compound was dissolved in 40.00 g of acetone, producing a solution that boils at 56.64°C. Kb for...

*April 14, 2010*

**6th grade**

how do I get the answer to: 4/5 pounds of mints for 10 students?

*April 12, 2010*

**geometry**

I have no clue

*April 6, 2010*

**Biology - Hormones**

estrogen is one

*April 5, 2010*

**Chemistry**

The Solvay process for the manufacture of sodium carbonate begins by passing ammonia and carbon dioxide through a solution of sodium chloride to make sodium bicarbonate and ammonium chloride. The equation for this reaction is H2O + NaCl + NH3 + CO2 → NH4Cl + NaHCO3. In ...

*April 3, 2010*

**Chemistry**

please help me out, thanks

*April 3, 2010*

**Chemistry**

Is that correct?

*April 3, 2010*

**Chemistry**

Barium sulfate, BaSO4 is made by the following reaction. Ba(NO3)2(aq) + Na2SO4(aq)----> BaSO4(s) + 2NaNO3(aq) An experiment was begun with 91.77 g of Ba(NO3)2 and an excess of Na2SO4. After collecting and drying the product, 62.3 g of BaSO4 was obtained. Calculate the ...

*April 3, 2010*

**Chemistry**

The Solvay process for the manufacture of sodium carbonate begins by passing ammonia and carbon dioxide through a solution of sodium chloride to make sodium bicarbonate and ammonium chloride. The equation for this reaction is H2O + NaCl + NH3 + CO2 ¨ NH4Cl + NaHCO3. ...

*April 2, 2010*

**MATH**

Let’s agree to say that a positive integer is prime-like if it is not divisible by 2, 3, or 5. How many prime-like positive integers are there less than 100? less than 1000? A positive integer is very prime-like if it is not divisible by any prime less than 15. How many ...

*April 2, 2010*

**math**

4. For the curve with y = -2x3 + x - 6, find: (b.) the gradient at the point (-1, -5) (c.) the equation of the tangent line at the point (-1, -5).

*April 1, 2010*

**Math**

Find the value(s) of x, so that f’(x) = 0 for the function f(x) = 4x3 – 6x2 – 24x.

*April 1, 2010*

**Physics**

(9.0e^9)(1)(1)/(1)^2 = 9.0e^9 (9.0e^9)(1/4)(1) = 2.25e^9 2.25e^9/(1/2)^2 = 9.0e^9 1/2*d

*March 29, 2010*

**chemistry**

One gram of TNT, C7H5N3O6, has 1.33 ´ 1022 hydrogen atoms. How many carbon atoms are there in 1.00 g of TNT?

*March 29, 2010*

**calculus**

(6+2y)/(3*sqrt(9-y^2)) = Ae^(kt) How do you show the steps to figure what y equals?

*March 29, 2010*

**calculus**

(6+2y)/(3*sqrt(9-y^2)) = Ae^(kt) How do you show the steps to figure what y equals?

*March 29, 2010*

**economic**

3. Consumer spending on durables falls, draw a graph to analyze the effects of this change in real interset. 4. The Canadian demand for Mexican Pesos is downward sloping and supply of pesos is upward sloping. Assume a system of flexible exchange rate between Mexico and Canada...

*March 24, 2010*

**Chemestry**

the solubility of a gas is 0.34g/L at STP. What is it's solubility at a pressure of 0.80 atm and the same temperature?

*March 22, 2010*

**Chemistry**

i don't no

*March 22, 2010*

**Math**

Carrie and Crystal live at a equal distances from school. Carries walks to school at an average rate of 3 miles per hour and Crystal rides her bike at an avergae rate of 9 miles per hour. It takes Carrie 20 minutes longer than Crystal to get to school. How far do Crystal and ...

*March 20, 2010*

**History**

This should actually be historian Richard Pipes

*March 18, 2010*

**History**

Why is historian Orlando Figes so against Lenin's actions - especially in the February and October revolutions

*March 18, 2010*

**6th Grade Grammar**

Thank you.

*March 17, 2010*

**6th Grade Grammar**

The sixth grade class *had wrote* several papers about the great sphinx. How should the words in the asterisks be written? A. had written b. has wrote c. correct as is

*March 17, 2010*

**6th Grade Grammar**

Thank you.

*March 17, 2010*

**6th Grade Grammar**

Present perfect, past perfect or future perfect. This month, we have learned about the great sphinx.

*March 17, 2010*

**6th Grade Grammar**

Present perfect or past perfect. The two have worked together to write a book.

*March 17, 2010*

**6th Grade Grammar**

Past perfect or present perfect. Raj has told the reporter about his new ideas.

*March 17, 2010*

**6th Grade Grammar**

Past perfect or present perfect. A reporter has interviewed him several times.

*March 17, 2010*

**English**

Its a letter to the editor we are analysing.

*March 17, 2010*

**English**

Language Analysis Please help me find persuasive techniques/statements in the following article.. I've never done this before, and I've "stewed" over the subject for the last couple of days, but I'm absolutely incensed that the Victorian Government will ...

*March 17, 2010*

**math**

how would you factorise a) 9x^2 - 49 b) 9x^2 - 121 c) 49x^2 - 25x^2 thankyou

*March 14, 2010*

**Science 6th Grade**

When the frequency of a note is twice the frequency of another, the notes are a(n) ______________ apart.

*March 14, 2010*

**Science 6th Grade**

Light, XRays, and radio waves contain _____________ with different amounts of energy.

*March 14, 2010*

**computers**

i need this decrypted if anyone can help that would be great 1b4a045c34a0573ca57657a1021dc171

*March 12, 2010*

**chemistry**

Most natural gas consists of about 90% methane, CH4. Assume that the solubility of natural gas at 20 C and 1 atm gas pressure is about the same as that of CH4, 0.02 g/kg water. If a sample of natural gas under a pressure of 20 atm is kept in contact with 1.00 *10^3 kg of water...

*March 8, 2010*

**math**

Nature's best wants to combine nuts they sell for $3.60 a pound with dried fruit they sell for $2.40 a pound to create a trail mix. How much of each snack should they use to make 10 pounds of trail mix that would sell for $3.30 a pound? Thank you!

*March 7, 2010*

**Computer**

OMG totally didn't see that, thank you!

*March 6, 2010*

**Computer**

This problem is a base conversion problem masquerading as a "word problem". You are responsible for controlling the stage lights at a small theater. The control box has control switches for 10 separate lights, and each switch can make its corresponding light off, red...

*March 6, 2010*

**Chemistry-Equation**

1.67 mol in a balanced equation there 6 mol of oxygen for every 1 mol of glucose; so ratio is 6 to 1. 10 mol oxygen/ 6 = 1.67...

*March 5, 2010*

**math**

I just have to tell if the are equal or equivalent or both, or neither. I think the answer is both but not sure

*March 4, 2010*

**math**

L,M,N,O and l,m,n,o are they equal, equivalent or neither? I can not figure this out please help.

*March 4, 2010*

**geometry**

When the number w is multiplied by 4, the result is the same as when 4 is added to w. What is the value of 3w

*March 3, 2010*

**geometry**

If p is an interger and 3 is the remainder when 2p+7 is divided by , then p could be what?

*March 3, 2010*

**physics**

1.8*10^4

*March 3, 2010*

**Math**

A farmer has a dog, two geese and three bags of corn. He comes to a river. The boat to ferry him across the river can only hold the man plus two of his six possessions at a time. The farmer knows that if he is not right there the dog will eat a goose or a goose will eat the ...

*March 2, 2010*

**math**

(3n^4)^4 = 3d^3 x d^9 = 5e^4 x 6e^5 = thanks

*February 28, 2010*

**Literature**

In "A Pair of Silk Stockings," are a symbol of

*February 27, 2010*

**11th grade**

Factor f(x) = x^4 + x^3 – 8x^2 + 6x + 36 completely. Show all steps.

*February 24, 2010*

**chemistry**

When the glucose solution described in part A is connected to an unknown solution via a semipermeable membrane, the unknown solution level rises. Based on this information, what can be said about these two solutions? a.) The unknown solution had the lower concentration. b.)The...

*February 24, 2010*

**chemistry**

When the glucose solution described in part A is connected to an unknown solution via a semipermeable membrane, the unknown solution level rises. Based on this information, what can be said about these two solutions? a.) The unknown solution had the lower concentration. b.)The...

*February 24, 2010*

**chemistry**

nevermind i got it

*February 24, 2010*

**chemistry**

In the reaction A to products, A is found to be 0.489 M at t=72.0 s and 0.468 M at t=82.2 s What is the average rate of the reaction during this time interval? Do I take the Ln (0.468/0.489) = -0.04395 / 10.2 = 4.3 * 10^3. yet the comp says its wrong. i have to put it to two ...

*February 24, 2010*

**chemistry**

A 355g sample of a saturated solution of KNO3(s) in water is prepared at 25.0 degrees C. If 50g H2O is evaporated from the solution at the same time as the temperature is reduced from 25.0 to 0.0 degrees C, what mass of KNO3(s) will recrystallize? i have no idea where to start...

*February 22, 2010*

**chemistry**

Nope he has not responded

*February 21, 2010*

**chemistry**

How many grams of water would you add to 1.00 kg of 1.48 m CH3OH(aq) to reduce the molality to 1.00 m CH3OH. Use two sig figs. I get 4.8 * 10^2 grams and its not right. I want to put this up here again to see if there are any errors that could have possibly been made. (Putting...

*February 21, 2010*

**chemistry**

so would the answer be 4.8 * 10 ^ -2?? if its fewer?

*February 21, 2010*

**chemistry**

How many grams of water would you add to 1.00 kg of 1.48 m CH3OH(aq) to reduce the molality to 1.00 m CH3OH. Use two sig figs. I get 4.8 * 10^2 grams and its not right. I want to put this up here again to see if there are any errors that could have possibly been made

*February 21, 2010*

**chemistry**

How many grams of water would you add to 1.00 kg of 1.48 m CH3OH(aq) to reduce the molality to 1.00 m CH3OH. Use two sig figs. I get 4.8 * 10^2 grams and its not right. I want to put this up here again to see if there are any errors that could have possibly been made

*February 21, 2010*

**Statistics**

How do you know the p-value on megastat. On minitab It looks like it gets a different p-value than megastat. I got a number from megastat of 2.35E10 and on minitab it was 0.000.

*February 21, 2010*

**math**

Without finding the exact answer, select which of the following numbers is the best estimate of each sum or difference and justify your choices: -2/3, 0, 2/2/3. a. 1/9 + 2/5 – 1/3 – 3/4 I am confused on where to begin on this question.

*February 21, 2010*

**chemistry**

How many milliliters of glycerol, C3H8O3(d=1.26g/mL), must be added per kilogram of water to produce a solution with 4.85 mol % C3H8O3? Kinda lost -.-;

*February 21, 2010*

**chemistry**

If a hydrate of the formula decomposes when heated to produce HCl, what change would you expect to occur when a piece of blue litmus paper is held in the path of the vapor released? [Litmus paper is paper impregnated with an acid-base indicator that is blue in the presence of ...

*February 20, 2010*

**chemistry**

sorry would i multiply the moles of O2 by the 1(0.208) to get the concentration which is proportional to the molarity?

*February 20, 2010*

**chemistry**

Okay, so this is how I think I should set it up? can you confirm it at least. Anyways I would try to find moles of O2 using ideal gas law (1.00 atm)(0.283)/(0.0821)(298) = n moles O2. then I would multiply 0.208 by the 1 L of water?? Then divide the moles of O2 / by L of water...

*February 20, 2010*

**chemistry**

Under an O2 pressure of 1.00 atm, 28.31 mL of O2 dissolves in 1.00 L H2O at 25 degrees. Determine the molarity of O2 in an aqueous solution at equilibrium with air at normal atmospheric pressure. The volume percent of O2 in air is 20.80 \%. (Have no idea how to go through with...

*February 20, 2010*

**chemistry**

oh. that's the complete opposite of what i thought. thanks

*February 20, 2010*

**chemistry**

An ideal liquid solution has two volatile components. In the vapor in equilibrium with the solution, the mole fractions of the components are (a) both 0.50; (b) equal, but not necessarily 0.50; (c) not very likely to be equal; (d) 1.00 for the solvent and 0.00 for the solute. ...

*February 20, 2010*

**chemistry**

Under an O2 pressure of 1.00 atm, 28.31 mL of O2 dissolves in 1.00 L H2O at 25 degrees. Determine the molarity of O2 in an aqueous solution at equilibrium with air at normal atmospheric pressure. The volume percent of O2 in air is 20.80 \%. (Have no idea how to go through with...

*February 20, 2010*

**chemistry**

nope. have to contact my teacher about this.

*February 20, 2010*

**chemistry**

How many grams of water would you add to 1.00 kg of 1.48 m CH3OH(aq) to reduce the molality to 1.00 m CH3OH? Ok...I got 480, and the systems says there's a rounding error. I did it again and I got 480. Someone help me?

*February 20, 2010*

**biology 102**

I've already done it, thank you. Was wondering if there were any other predictions.

*February 19, 2010*

**biology 102**

A prediction (educated guesses as to what the potential results may be) for each experiment listed below: 1) knee-jerk reflex 2) pupillary reflex (shield left eye, shine bright light into right eye, observe pupils) 3) 2-point threshold 4) temperature discrimination 5) ...

*February 19, 2010*

**business**

describe two forces that you believe shape the relationship between business and society. Provide two examples (one for each force you choose). Look for flaws and strengths in specific examples and applications

*February 18, 2010*

**MATH**

a<9. Not sure about the graph 3a<19+8 3a<27 a<27/3 a<9

*February 17, 2010*

**Math**

That's what I got.

*February 17, 2010*

**Chemistry**

Explain how to make a 1 Normal solution H3PO4.

*February 17, 2010*

**Chemistry**

What is the normality of 10 ml of an acid that took 25 ml of 0.25 N NaOH to reach pH 7?

*February 17, 2010*

**Chemistry**

You were using H3PO4 to make an acid solution. What is the equivalent weight of H3PO4

*February 17, 2010*

**Chemistry**

if you have 100 mg of CaCl2, how many moles of Cl do you have

*February 17, 2010*

**CHEMISTRY**

what is 0.00225 in two sigs? i hate sig figs -.-. thank you though.

*February 12, 2010*

**CHEMISTRY**

I calculated using the proportion and got 0.00025, and it was wrong. Then I used 9 ppb times 1000000 ml/ 1 ppb = 9000000, and used the proportion setup and still got it wrong.

*February 12, 2010*

**CHEMISTRY**

1.) A water sample is found to have 9.0 ppb of chloroform,CHCL3. How many grams of CHCL3 would be found in a glassful (250 ML) of this water?

*February 12, 2010*

**chemistry**

The second one is correct. Regarding the first one though, I calculated the grams to 6.8 g of C2H5OH. I don't quite understand the next step (regarding the density, etc)

*February 12, 2010*

**College Math : Linear Algebra**

Well I guess no one can help. :/ Oh well, I'll figure it out

*February 9, 2010*