Thursday

May 26, 2016
Total # Posts: 3,243

**Chemistry**

How many grams of NaF should be added to 612 ml of 0.4 M HF (Ka = 6.8 x 10-4) to produce a buffer solution where pH = 3.10?
*April 12, 2013*

**problem solving**

ou are completing the final exam in your class. Your instructor’s assignment instructions state that you may only use the following resources: library books, class notes, texts, and the instructor. You and your roommate discussed one of the questions, but you wrote your ...
*April 12, 2013*

**Chemistry **

How much energy would be released when 675 grams of steam is condensed to water
*April 11, 2013*

**place vowlue**

2 tens and333 hundreds
*April 10, 2013*

**Math**

3+3+4+4=14 feet for each window,3 feet wide and 4 feet high.You have 5 windows so what is 5x14?
*April 9, 2013*

**Algebra**

Given f(x)=-4+lnx; Find the inverse of f. f^-1=?
*April 7, 2013*

**Math**

a curve is such that dy/dx=4x+7. the line y=2x meets the curve at point 'P'. Given that the gradient of the curve at P is 5. State the coordinates of P.
*April 7, 2013*

**math**

ONE-NINTH
*April 7, 2013*

**math**

1rad=180/pi degrees. so 174=f degrees. cross multiply and get f=174 x 180/pi. where f represents the unknown degrees.
*April 7, 2013*

**MATH**

Complete the square method.
*April 7, 2013*

**MATH**

ok, divide throughout by logv3 and then you will get a quadratic equation and solve for t.
*April 7, 2013*

**MATH**

remember to divide the terms when subtracting in logarithms.
*April 7, 2013*

**science asap**

altitude on the horizontal axis and pressure on vertical because the independent variable always goes on the horizontal axis, and in this case pressure changes depending on the altitude.
*April 7, 2013*

**math**

What does a lower perfect square and a upper perfect square mean.
*April 7, 2013*

**Math**

a curve is such that dy/dx=4x+7. the line y=2x meets the curve at point 'P'. Given that the gradient of the curve at P is 5. State the coordinates of P.
*April 7, 2013*

**Pre-Algebra**

6,7,8
*April 7, 2013*

**Math**

Yeah it's 1. 22-12-9=1
*April 7, 2013*

**Math**

No it is not.
*April 7, 2013*

**math**

Write the slope Intercept form of the depletion of the line that contains -4,6 and 6,-1
*April 6, 2013*

**Philosphy**

what is the role of the agent intellect? I know it illuminates and then abstracts the phantasm, but not really understanding completely..thank you
*April 6, 2013*

**geometry**

LMNO is a parallelogram. If NM = x + 15 and OL = 3x + 5, find the value of x, then find NM and OL
*April 5, 2013*

**Chemistry**

How do i calculate the number of moles of mg in 0.303 reacted
*April 4, 2013*

**Analytical chemistry**

A 25.0-mL solution of 0.0660 M EDTA was added to a 33.0-mL sample containing an unknown concentration of V3 . All V3 present formed a complex, leaving excess EDTA in solution. This solution was back-titrated with a 0.0450 M Ga3 solution until all the EDTA reacted, requiring 13...
*April 4, 2013*

**Analytical chemistry**

Calculate pCd2 at each of the following points in the titration of 40.00 mL of 0.0040 M Cd2 with 0.0040 M EDTA in the presence of the auxiliary complexing agent NH3. The solution is buffered at a pH of 11.00. Take the NH3 concentration to be a constant 0.100 M. The formation ...
*April 4, 2013*

**chemistry**

A 50.00-mL sample of groundwater is titrated with 0.0900 M EDTA. Assume that Ca2 accounts for all of the hardness in the groundwater. If 11.40 mL of EDTA is required to titrate the 50.00-mL sample, what is the hardness of the groundwater in molarity and in parts per million of...
*April 4, 2013*

**chemistry**

The concentration of saturated NaOH is 50.0% w/w and the density is 1.52 g/mL. If exactly 8.50 mL were diluted to 1.000 L, what would be the concentration?
*April 4, 2013*

**chemistry**

A solution of the primary standard potassium hydrogen phthalate, KHC8H4O4, was prepared by dissolving 0.4877 g of potassium hydrogen phthalate in about 50 mL of water. Titration with a KOH solution required 17.65 mL to reach a phenolphthalein end point. What is the molarity of...
*April 4, 2013*

**Analytical chemistry**

A 24.393 g sample of aqueous waste leaving a fertilizer manufacturer contains ammonia. The sample is diluted with 80.601 g of water. A 12.404 g aliquot of this solution is then titrated with 0.1059 M HCl. It required 31.61 mL of the HCl solution to reach the methyl red ...
*April 4, 2013*

**chemistry**

The pKb values for the dibasic base B are pKb1 = 2.1 and pKb2 = 7.4. Calculate the pH at each of the following points in the titration of 50.0 mL of a 0.75 M B(aq) with 0.75 M HCl(aq). (b) after addition of 25.0 mL of HCl (c) after addition of 50.0 mL of HCl (d) after addition...
*April 4, 2013*

**chemistry**

0.650 L of 0.420 M H2SO4 is mixed with 0.600 L of 0.280 M KOH. What concentration of sulfuric acid remains after neutralization?
*April 4, 2013*

**Chemistry**

Of the 3 types of fat, which type of fat would react with the greatest amount of bromine? Least amount of bromine? a. saturated fat b. mono-unsaturated fat c. poly-unsaturated fat
*April 2, 2013*

**physics**

block 1 has mass m1 = 480 g, block 2 has mass m2 = 540 g, and the pulley is on a frictionless horizontal axle and has radius R = 5.2 cm. When released from rest, block 2 falls 76 cm in 5.2 s (without the cord slipping on the pulley). What is the pulley's rotational inertia...
*April 2, 2013*

**physics**

The average rate at which energy is conducted outward through the ground surface in a certain region is 66.8 mW/m2, and the average thermal conductivity of the near-surface rocks is 2.13 W/m·K. Assuming a surface temperature of 8.01°C, find the temperature (in ...
*April 1, 2013*

**physics**

In a solar water heater, energy from the Sun is gathered by water that circulates through tubes in a rooftop collector. The solar radiation enters the collector through a transparent cover and warms the water in the tubes; this water is pumped into a holding tank. Assume that ...
*April 1, 2013*

**Statistics**

A) 0.153 B) 0.753 C) 0.095
*March 30, 2013*

**Philosophy**

Show that (P → Q) ↔ (¬P ∨ Q) in fitch
*March 29, 2013*

**Math**

thanks
*March 28, 2013*

**Math**

What is 9/20 in simplest form?
*March 28, 2013*

**french**

I need to complete activity 11 noms et prenoms with the verb appeler, it's French 3 in the la routine quotidienne packet?
*March 27, 2013*

**Chemistry 140A**

A gas cylinder containing 6.38 mol of neon has a pressure of 491 mm Hg at 295 K. If 3.22 mol of helium is added to this cylinder, at constant temperature and volume, what will be the pressure in the cylinder?
*March 26, 2013*

**Form a polynomial f(x)**

Form a polynomial f(x) with the real coefficients having the given degree and zeros. Degree 5; Zeros: -3; -i; -6+i f(x)=a( )
*March 26, 2013*

**College algebra**

Form a polynomial f(x) with the real coefficients having the given degree and zeros. Degree 5; Zeros: -3; -i; -6+i f(x)=a( )
*March 26, 2013*

**Find the complex zeros**

Find the complex zeros of the polynomial function. Write f in the factored form. f(x)=x^3-3x^2+7x-5 f(x)=
*March 26, 2013*

**Use the intermediate value**

Use the intermediate value theorem to show that the polynomial function has a zero in the given interval. f(x)=4x^3+6x^2-7x+1; [-4,-2] f(-4)=
*March 26, 2013*

**math **

I need help with these two problems please. Completely factor the polynomial. 8x^3+16^2+8x+16 Factor the trinomial completely. y^3-14y^2+48y
*March 24, 2013*

**Science**

Which would you measure in millimeters , a capacity of a juice box or the capacity of a water pitcher?
*March 23, 2013*

**quantitative chemistry**

Na2HAsO4 neutral compound
*March 22, 2013*

**Chemistry**

At 122C the pressure of a sample of nitrogen gas is 0.830 atm. what will the temperature in Celsius be at 3.00 atm, assuming constant volume ?
*March 20, 2013*

**Biology**

What was a event in Darwins life that lead him to the theory of evolution. When i googled it those were the only two that came up. And our teacher told us to not to do those
*March 20, 2013*

**Biology**

What was a event in Darwins life that lead him to the theory of evolution. When i googled it those were the only two that came up. And our teacher told us to not to do those
*March 20, 2013*

**Biology**

Research and discuss an event in Charles Darwins' life that lead to his theory of evolution. Events could be directly in Charles Darwin's life or could be individuals whose ideas Darwin incorporated into his work. Besides the voyage to Beagle and the visit to the ...
*March 20, 2013*

**Chemistry**

In an experiment with a titration of Vitamin C with Iodine, why must the iodine dropper be standardized?
*March 19, 2013*

**Chemistry**

A student completed the standardization procedure & found that the value for her dropper was 0.133 mg Vitamin C/dp l2. The student then selected a juice & titrated it with the iodine from the dropper bottle. The sample turned blue with the addition of the 19th drop. How many ...
*March 19, 2013*

**Chemistry**

During the standardization procedure of the iodine dropper, a student used 10.0 mL of a 1.00 mg.mL standard of Vitamin C. After adding 41 drops of iodine to the 10.0 mL of the standard, the sample was a deep blue. Calculate how many mg of Vitamin C are titrated by each drop of...
*March 19, 2013*

**Physics**

Somehow, I got the right magnitude, but my x and y are different. my x=-21.35 and y=13.9 how?
*March 18, 2013*

**Physics**

A charge of -3.66C is fixed at the center of a compass. Two additional charges are fixed on the circle of the compass (radius = 0.0978 m). The charges on the circle are -4.04C at the position due north and +6.20C at the position due east. What is (a) the magnitude and (b) ...
*March 18, 2013*

**word puzzle**

italian
*March 18, 2013*

**geography**

thank you Ms. Sue, i appreciate it :)
*March 18, 2013*

**geography**

landlocked and high elevation?
*March 18, 2013*

**geography**

THANK YOU bolivia-is it because of their high indig. population and poverty? col-coca leaf? central Colombia brzil-#1 producer in oranges, soybean, sugarcane, and coffee. Most common resources include iron ore, aluminum, and gold has complete access to Atlantic ocean\ brasilia...
*March 18, 2013*

**geography**

1. Bolivia is pretty isolated--why? 2. Columbia has an important resource--what is it, where is it? 3. Brazil has many resources--where are they? Access? 4. Why is Brazilia a forward capital? 5. What is Cuba's access? Why does the US have a trade embargo against? What ...
*March 18, 2013*

**geomerty**

the hexagon GIKMPR and triangle FJN are regular the dashed line segments form 30 degree angles
*March 17, 2013*

**Physics**

A 5.81 10-5 H solenoid is constructed by wrapping 62 turns of wire around a cylinder with a cross-sectional area of 8.20 10-4 m2 When the solenoid is shortened by squeezing the turns closer together, the inductance increases to 8.94 10-5 H. Determine the change in the length ...
*March 17, 2013*

**Physics**

The coil of a generator has a radius of 0.12 m. When this coil is unwound, the wire from which it is made has a length of 5.8 m. The magnetic field of the generator is 0.21 T, and the coil rotates at an angular speed of 26 rad/s. What is the peak emf of this generator? Answer ...
*March 17, 2013*

**Physics**

The coil of a generator has a radius of 0.12 m. When this coil is unwound, the wire from which it is made has a length of 5.8 m. The magnetic field of the generator is 0.21 T, and the coil rotates at an angular speed of 26 rad/s. What is the peak emf of this generator? Answer ...
*March 17, 2013*

**Math - Grade 5**

A shop sells candies by weight. Monisha bought 2 full bags of chocolates and 3 full bags of gummy bears for $23.50. If 3/4 of a bag of chocolate cost as much as 5/6 of a bag of gummy bears, find the cost of 1 full bag of chocolates.
*March 16, 2013*

**Math - Grade 5**

After saving 4/5 of his salary every month, Zacky has $150 left. Micah saves 6/7 of his salary every month. If both guys save an equal amount each month, how much is their combine salary?
*March 16, 2013*

**Chemistry**

1.77
*March 14, 2013*

**artist**

Is it possible for a band or artist to make topical or political commentary in a song today while focusing on turning a profit?
*March 14, 2013*

**chemistry**

I need 1L of a pH 4 buffer with a total molarity of 1. Propose a buffer system and a recipe to achieve this goal. (acetic acid/acetate would probably be a good choice.) help please!
*March 12, 2013*

**chemistry**

I need 1L of a pH 4 buffer with a total molarity of 1. Propose a buffer system and a recipe to achieve this goal. (acetic acid/acetate would probably be a good choice.) help please!
*March 12, 2013*

**chemistry**

1L of a buffer composed of acetic acid and sodium acetate has a pH of 4.3 (total molarity=0.0774) what is the capacity of 200mL of the buffer to survive an addition of HCl without changing by more than 0.4 pH units? i am so lost please help! i know you use the henderson ...
*March 12, 2013*

**chemistry**

I need 1L of a pH 4 buffer with a total molarity of 1. Propose a buffer system and a recipe to achieve this goal. (acetic acid/acetate would probably be a good choice.) help please!
*March 12, 2013*

**chemistry**

1L of a buffer composed of acetic acid and sodium acetate has a pH of 4.3 (total molarity=0.0774) what is the capacity of 200mL of the buffer to survive an addition of HCl without changing by more than 0.4 pH units? i am so lost please help! i know you use the henderson ...
*March 12, 2013*

**Chemistry **

What is the concentration (in M) of an ammonia (NH3) solution if 12.23 grams of ammonia are dissolved to make a 520 mL solution?
*March 11, 2013*

**chemistry**

i got a total concentration of 0.0774M is this correct?
*March 10, 2013*

**chemistry**

for a i got pH=3.97 and for b i got 3.99 for c and d i am stuck.
*March 10, 2013*

**chemistry**

i am suppose to calculate the pH at the new conditions, but i am super lost. also for c and d i think you would have to figure out the moles, but then i do not know what to do from there.
*March 10, 2013*

**chemistry**

1L of a buffer composed of NaHC2O4 and Na2C2O4 has a pHof 4.0 and a total molarity of 1. a). what would the effect on the pH be of adding 1 gram of sodium hydrogen oxalate to this buffer? b). what would be the effect on the pH of adding 1 gram of sodium oxalate to the original...
*March 10, 2013*

**chemistry**

for LiNO3 i found the ionic strength to be .02M for KClO4 i found the ionic strength to be .05M for NaF i found the ionic strength to be .01M i'm stuck on what else to do from here.
*March 10, 2013*

**chemistry**

Find the concentration of Ag+ in a saturated solution of AgBrO3 that also contains 0.02M LiNO3, 0.02M KClO4 and 0.01M NaF.
*March 10, 2013*

**chemistry**

for my answer i got 597559.1682 is this correct??
*March 10, 2013*

**chemistry**

For the reaction 2A(g) + B(aq) + 3C(l)<------> D(s) + 3E(g), the concentrations at equilibrium are found to be: A: 2.3x10^3 Pa B: 1.8x10^-2 M C: 15.8M D: 12.5M E: 5.6x10^4 Torr Find the numerical value of the equilibrium constant that would appear in a conventional table...
*March 10, 2013*

**chemistry**

How do i calculate the pKa??
*March 9, 2013*

**chemistry**

How many grams of Na2CO3 should be mixed with 50.00g of NaHCO3 to produce 2000mL of buffer with pH=10?
*March 9, 2013*

**Calculus**

square root of (12), square root of (12 + square root of (12)), square root of (12+ square root of (12+ square root of (12))) Write a recursion formaula for an(subcription), n greater than or equal to 2.
*March 7, 2013*

**Management for Organizations**

Would someone PLEASE check my answers..THANKS in advance!!! 1. Employee inventories and skills inventories are strategies for ________________________. (D) job design promoting-from-within external recruiting human resource planning 2. Which one of the following choices is not...
*March 7, 2013*

**Math**

A maple tree casts a shadow of 45 ft long. At the same time, a 40-ft-long oak tree casts a shadow which is 60 ft long. Explain how you can use similar triangles to find the height of the tree. Then find the height of the tree.
*March 5, 2013*

**algebra**

the primeter of a rectangle is 24ft. the length is 2 ft longer than the width. Find the dimensions. Write a system of linear equations and solve the resulting system. Let x be the length and y be the width. is the answer for the length 14ft and the width 10 ft?
*March 5, 2013*

**algebra**

thanks so much.
*March 5, 2013*

**algebra**

I am getting lost here. I came up with 8 ft for the length and 4 ft for the width. I hope this is right.
*March 5, 2013*

**algebra**

okay 14ft for length and 10 for the width.
*March 5, 2013*

**algebra**

the primeter of a rectangle is 24ft. the length is 2 ft longer than the width. Find the dimensions. Write a system of linear equations and solve the resulting system. Let x be the length and y be the width. Is the answer for the lenght 16ft and 8ft for the width?
*March 5, 2013*

**algebra**

correction length is 8ft and width is 4 ft.
*March 5, 2013*

**algebra**

okay. I came up with 14ft for the length and 10ft for the width.
*March 5, 2013*

**algebra**

the primeter of a rectangle is 24ft. the length is 2 ft longer than the width. Find the dimensions. Write a system of linear equations and solve the resulting system. Let x be the length and y be the width, write the first equation. 2x+2y=__ write the second equation. x=y+__ ...
*March 5, 2013*

**Math**

You just type in 2.3 x 1.2= ... and it equals to... 2.76. Hope this helped you
*March 5, 2013*

**algebra**

X=10.5 y=13 ...so, you place them in cordinate pairs, like this: (10.5,13) x y Hope this helped.
*March 5, 2013*

**Geometry**

line xy bisect and is perpendicular to ab and cd. ab=6 and ap=5 what is the length of xy
*March 4, 2013*