Wednesday

July 29, 2015

July 29, 2015

Total # Posts: 1,163

**Chemistry**

If a saturated solution prepared by dissolving solid BaSO4 in water has [Ba2+]= 1.04*10^5M, what is the value of Ksp for BaSO4?
*February 8, 2011*

**Biochemistry**

Complete hydrolysis of 25 mM ethyl acetate in an enzyme esterase catalyzed reaction is carried out in a 40 mM NaCl solution buffered by 0.2 M Tris-Cl, pH 9.1. What is the pH at the end of the reaction? (For Tris base, which is the abbreviation for Tris (hydroxymethyl) ...
*February 7, 2011*

**math**

Angle U and Angle V are complementary angles. If Angle U is three less than twice Angle V, what are the measures of the angles?
*February 6, 2011*

**Math-Equations**

I haven't posted this before. I've been working on this for 2 days and I didn't search the website for this problem again today. Someone else must have posted it. I just couldn't figure out the equations. Thanks anyway.
*February 6, 2011*

**Math-Equations**

A building contractor is planning to build an apartment complex with one, two or three bedroom apartments. Let x,y,z respectively denote the number of apartments of each type to be built. Suppose that the builder will spend a total of $6,885,000, and that the costs for the ...
*February 6, 2011*

**Chemistry**

A 119.2mL sample of 0.105M methylamine (CH3NH2, Kb=3.7*10^-4) is titrated with 0.255M HNO3. Calculate the after the addition of each of the following volumes of acid. 49.1mL and 73.6mL. Please help.
*February 6, 2011*

**Chemistry**

A 23.0mL sample of a diprotic acid is titrated with 0.260M KOH. If 55.5mL of base is required to reach the second equivalence point, what is the concentration of the acid? I'm not sure how to do this.
*February 6, 2011*

**Algebra**

The area of the top of a triangular corner desk must be at least 7 sq. ft. If the base of the triangular desk top needs to be four feet, what should the height be?
*February 6, 2011*

**new age math**

Please someone help
*February 6, 2011*

**new age math**

A value of the number k for which there is either no solution or an infinite number of solutions for (y,v) to the system of equations show below 7y-9v=-9 Ky+7v=7
*February 6, 2011*

**geometry**

if 32 degrees is less than three times its supplement, how large is the angle?
*February 5, 2011*

**AP Chem**

I figured out the first part but don't understand the second part still. I looked at the response you had for someone else, but still couldn't get the right answer.
*February 2, 2011*

**AP Chem**

The formula for epson salts is MgSO4*7H2O. If 1.250 g of the compound is dissolved in water, calculate the number of milliliters of 0.200 M Ba(NO3)2 that would be required to precipitate all of the sulfate ions as barium sulfate. Make the same determination for 1.000 g of alum...
*February 2, 2011*

**English**

How can I rewrite this sentence: A boy and his bog sat by a house?
*February 2, 2011*

**math**

joseph is planning a 2500 mile cross-country trip in his new sports utility vehicle. he uses the following information about his vehicle to figure out how much money to budget for gas: . the vehicle has a 15 gallon tank . the vehicle gets 25 miles per gallon if the gasoline ...
*January 31, 2011*

**math**

sandra is making 3 gallons of lemonade reception.If each scoop of powdered lemonade mix dissolves in enough water to make 3 quarts of punch,how many scoops of powdered mix will she use? ( hint: 4 quarts = 1 gallon
*January 31, 2011*

**Supply/Math**

The suppliers will supply 3,300 units if the price is $350.00 and 3,800 units if the price becomes $410.00. Then the linear supply equation is p = ? s + ? .
*January 30, 2011*

**math**

The question says .. match the equivalent addition and subtraction expressions a) -6 -9 b)-10 - (-12) c)6-9 d)10-12 e)-12-10 A)10+(-12) B)-6+(-9) C)-12 + (-10) D)6+(-9) E)-10+12
*January 26, 2011*

**math**

The question says .. match the equivalent addition and subtraction expressions a) -6 -9 b)-10 - (-12) c)6-9 d)10-12 e)-12-10 A)10+(-12) B)-6+(-9) C)-12 + (-10) D)6+(-9) E)-10+12
*January 26, 2011*

**Place Value**

Choose between the numbers 0, 2, 3, 4, 5, and 6 to make the largest four digit natural number in terms of value that you can. The number 078 has two digits. The number 00045 has two digits. Choose between the same numbers to make the smallest four digit number in terms of ...
*January 19, 2011*

**physics**

Find a vector with a magnitude of 1.00 that bisects the angle between the vectors 5.00i + 11.0j and 2.00i − 1.00j. Give your answer in rectangular coordinates. Please explain how you arrived at the solution. Thanks!
*January 19, 2011*

**Algebra**

Using the following six digits, 1, 2, 4, 6, 8, and 9, fill in the blanks below to make the maximum product that you can. Use each digit only once. How does an understanding of place value help determine the best solution to this problem?
*January 17, 2011*

**economics**

what are the non-monetary benefits of growing tobacco, of working as a plumber's assistant, and of working as a carpenter during the spring and summer and storing travel trailers for a local campground and selling oysters during the fall and winter?
*January 17, 2011*

**Principles of Macroeconomics**

What are the non-monetary benefits of growing tobacco, of working as a plumbers assistant, and of working as a carpenter during the spring and summer and storing travel trailers for a local campground and selling oysters during the fall and winter?
*January 17, 2011*

**physics**

How many uniform, identical textbooks of width 25.0 cm can be stacked on top of each other on a level surface without the stack falling over if each successive book is displaced 3.00 cm in width relative to the book below it? If the books are 5.00 cm thick, what will be the ...
*January 16, 2011*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size 3
*January 10, 2011*

**Math: Algebra 2**

Factor Completely with respect to the intergers. 2x^3-3x^2+4x-6
*January 9, 2011*

**physics**

Two masses are suspended from a pulley as shown in the figure below (the Atwood machine). The pulley itself has a mass of 0.20 kg, a radius of 0.15 m, and a constant torque of 0.35 m·N due to the friction between the rotating pulley and its axle. What is the magnitude ...
*January 9, 2011*

**physics**

well i dont really know how to explain the first part sorry.. but a negative acceleration for a car means the car is stopping.
*January 9, 2011*

**social studies**

thanks for all the help!!!(:
*January 8, 2011*

**social studies**

no i am not
*January 8, 2011*

**social studies**

how do you learn how to cook or do a job in medieval times? how do u get the job to be a cook in medieval times?
*January 8, 2011*

**social studies**

how many outfits did cooks have in the medieval times
*January 8, 2011*

**social studies**

but how do people treat the cook in medieval times
*January 8, 2011*

**social studies**

how do people treat cooks in medieval times
*January 8, 2011*

**social studies**

how often do cooks in medieval times speak to the lord?
*January 8, 2011*

**social studies**

can cooks in medieval times get married and if so who to?
*January 8, 2011*

**social studies**

what would the materials be as a cook in medieval times?
*January 8, 2011*

**social studies**

in medieval times as a cook where on the manor estate is your shelter
*January 8, 2011*

**social studies**

how do cooks get a job in medieval times?
*January 8, 2011*

**social studies**

who would cooks in medieval times work for?
*January 8, 2011*

**social studies**

where did people work if they were a cook in medieval times
*January 8, 2011*

**math**

a.u.s nickel contains 3.9g of copper and 1.2g of nickel. how many kilograms of copper must be combined with 500 kg of nickel to make nickel coins?
*January 8, 2011*

**Grammar**

omg thank u soooooooooooo much
*January 6, 2011*

**physics**

A rope goes over a circular pulley with a radius of 6.3 cm. If the pulley makes four revolutions without the rope slipping, what length of rope passes over the pulley?
*January 5, 2011*

**Economics**

explain why the cost tructure associated with many kinds of information goods and services might imply a market supplied by a small number of large firms. At the same time, some internet businesses such as grocery home deliveries have continually suffered steeplosses ...
*January 2, 2011*

**Math**

Mark each of the following True or False. ___ a. All vectors in an orthogonal basis have length 1. ___ b. A square matrix is orthogonal if its column vectors are orthogonal. ___ c. If A^T is orthogonal, then A is orthogonal. ___ d. If A is an n*n symmetric orthogonal matrix ...
*January 2, 2011*

**Spanish**

Thank you-I understand it now more clearly
*December 21, 2010*

**Spanish**

How do I say I'm wearing black pants? "Llevo pantalones negro." or do I have to add an "s" to negro? Thank you
*December 21, 2010*

**Spanish**

Could someone help me please? Which of the following says "some strong men" in Spanish los hombres fuertes unos hombres fuertes I think it is unos hombres fuertes becuase the los hombres fuertes states the strong men, doesn't it
*December 21, 2010*

**physics**

Four identical masses of 2.7 kg each are located at the corners of a square with 1.4 m sides. What is the net force on any one of the masses?
*December 19, 2010*

**physics**

someone pleaaaase answer my question! i have no clue how to do it!
*December 19, 2010*

**physics**

A 70 kg man weighs 686 N on the Earth's surface. How far above the surface of the Earth would he have to go to "lose" 14% of his body weight?
*December 19, 2010*

**Physics**

A 3.90×10^2kg cube of ice at an initial temperature of -18.0degreesC is placed in 0.480kg of water at 41.0degreesC in an insulated container of negligible mass. Calculate the change in entropy of the system. I found the equilibrium temperature to be at 304.9K, then used ...
*December 7, 2010*

**chemistry**

what is the molarity of 275mL of a solution containing 23.83 mg of Mg Cl(2)<small 2
*December 3, 2010*

**Statistics**

A group of doctors is trying to see if a vaccine causes a certain type of disease. They take individuals with the certain disease and individuals without the disease. They then use research to estimate the relative incidence of the onset of the disease after the vaccination. ...
*December 3, 2010*

**physics**

An air puck of mass m1 = 0.45 kg is tied to a string and allowed to revolve in a circle of radius R = 1.0 m on a frictionless horizontal table. The other end of the string passes through a hole in the center of the table, and a mass m2 = 1.10 kg is attached to it. The ...
*November 30, 2010*

**physics**

A light spring of spring constant k = 160 N/m rests vertically on the bottom of a large beaker of water. A 5.00 kg block of wood (density D = 700 kg/m3) is connected to the spring, and the block ? spring system is allowed to come to a static equilibrium
*November 30, 2010*

**Chem**

what mass of calcium oxalate can be dissolved in 180 ml of distilled water before a precipitate forms?
*November 29, 2010*

**statistics**

In one history class, 34 students took an exam. The mean of the exam was 52 with a standard deviation of 13. If the instructor is going to assume data are normally distributed and assign grades on a curve, then she will assign an A to the top 10% of the class, B's to the ...
*November 29, 2010*

**english**

At my son’s very first softball game his team did not do very well. No one seemed to be able to hit the ball or run the bases when they were up to bat. When they were in the field they would either run from the ball or be nowhere near it when they attempted to catch it. ...
*November 29, 2010*

**science**

What are the hard and fast rules of Science, if any?
*November 24, 2010*

**6th grade**

Each letter in each questio stands for a 1-digit number. in each question, no two letters maystand for the same number. Two separate problems are unrelated.Find a value for each letter MOON Use Numbers 4,7,5,6,2.8,9,3 x AT ____ ACROSS
*November 21, 2010*

**chemisty **

what is the molarity of ZnCl2 that forms when 30.0 g of zinc completely reacts with CuCl2 according to the following reaction? Assume a final volume of 285 mL. Zn(s) + CuCl2(aq)--> ZnCl2(aq) + Cu(s)
*November 20, 2010*

**U.S history**

My two colonies are New Jersey and Pennsylvania.How are they similar and how are they different?Which one would you live in,and why?
*November 18, 2010*

**us history**

Think about two colonies.How are they similar?How are they different?Decide which colony you would like to live in.
*November 18, 2010*

**physics**

I know this has been posted many times but I keep trying and cannot get the right answer, A place kicker must kick a football from a point 39.9 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ...
*November 17, 2010*

**physics**

I know this has been posted many times but I keep trying and cannot get the right answer, A place kicker must kick a football from a point 39.9 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ...
*November 17, 2010*

**calculus**

Have you found an answer yet?
*November 16, 2010*

**Math**

I figured it out 1 gallon = 8 pints and to figure the 3/4. you take 3/4 x 8/1= 24/4 and that = 6. so 6+8=14
*November 16, 2010*

**Math**

nick has 1 3/4 gallon of milk how many pints does nick have. I think it is 14.
*November 16, 2010*

**Algebra**

Consistent and independent?
*November 13, 2010*

**Algebra**

3x-9y=63 2x-6y=-18 Solve system of equations by graphing then classify as Independent on dependent and consistent or inconsistent?
*November 13, 2010*

**Algebra**

I still don't understand?
*November 13, 2010*

**Algebra**

One canned juice is 20% orange juice: another is 10% orange juice. How many liters of each should be mixed together in order to get 10L that is 13% orange juice.How many liters of the 20%? How many liters of the 10%?
*November 13, 2010*

**Chemistry**

Ethanol burns to produce 1300.0 kJ/mol and has a heat capacity of 65.6 J/mol·K. If Dr. Porter has 1.00 L of liquid ethanol (density = 0.789 g/mL), what is the minimum mass of fuel that should be removed and burned to heat the remaining ethanol from 25 °C to 90 °...
*November 9, 2010*

**Chemistry**

Hydrofluoric acid etches glass by reacting with the silica in it according to the following equation. H° = 54.5 kJ and S° = 436.5 J/K Calculate G° at 25°C for this reaction.
*November 9, 2010*

**Physics**

Newton's third law says that for every action there is an opposite and equal reaction. Does that mean that the the average thrust force the gas exerts on teh engine and rocket would each be 5 N?
*November 7, 2010*

**Physics**

A typical model rocket engine exerts an average force of 5 N on its exhaust gas. How much average thrust force does the gas exert on the engine and rocket?
*November 7, 2010*

**Chem**

2 H2O (l) → 2 H2 (g) + O2 (g) Using the thermodynamic values to calculate accurate values of ΔHr and ΔSr, will the reaction be product favored at high temperature? Why? r stands for reaction
*November 5, 2010*

**Chem. only regarding formula. **

how do do calculate ΔHr and ΔSr?
*November 5, 2010*

**Chem. thankss!!!**

1.0 mol of water (c=4.184 J/g.oC), 1.0 mol of ethanol (c=2.46 J/g.oC), 1.0 mol of carbon tetrachloride (c=0.861 J/g.oC), and 1.0 mol of ethylene glycol (c=2.42 J/g.oC) at 50oC were each placed into a separate coffee cup calorimeter and the temperature recorded. The temperature...
*November 5, 2010*

**Chem**

In an experiment 50 g of a metal was heated to 100oC and placed in 200 g of a liquid at 25oC. Which of the following combinations of metal and liquid will produce the largest temperature increase in the liquid? (Assume that there is no energy transfer to the surroundings.) ...
*November 5, 2010*

**CHEM. **

Zinc is often used to calibrate calorimeters because it undergoes a very sharp phase transition from the solid to the liquid at 419.5oC. Calculate the enthalpy change when 5 g of zinc metal is heated from 100oC to the point where the entire sample is melted. (The heat of ...
*November 5, 2010*

**CHEM. help please**

Consider a system of 3 molecules, A, B, and C. Suppose the 3 units of energy can be distributed over the three atoms where each atom can have no energy, one unit, two units or 3 units of energy. Assume each of the 10 possible arrangements is equally probable. What's ...
*November 5, 2010*

**Chem Help please**

Consider a system of 3 molecules, A, B, and C. Suppose the 3 units of energy can be distributed over the three atoms where each atom can have no energy, one unit, two units or 3 units of energy. Assume each of the 10 possible arrangements is equally probable. What's ...
*November 5, 2010*

**Calculus**

Given the demand function q=173-5p, determine the price where demand has unit elasticity.
*November 4, 2010*

**Calculus**

Given the demand function q=173-5p, determine the price where demand has unit elasticity.
*November 4, 2010*

**Calculus**

the demand for ground chuck(hamburger) in a certain region of the US is given by q= 3.41p^-0.22. is the demand for ground chuck elastic or inelastic
*November 4, 2010*

**Calculus**

a local office supply store has an annual demand for 50,000 cases of photocopier paper per year. it costs $2 per year to store a case of photocopier paper, and it costs $50 to place an order. Find the optimum number of cases of photocopier paper per order
*November 4, 2010*

**CHemistry**

Use the bond energies given in the "Bond Energy" table (can be gained from google) to estimate the delta Ho for the reaction given below. 2ClF3(g) + 2O2(g) Cl2O(g) + 3OF2(g) I did this: 1530 + 996 - (410 + 570) = 1546. But the answer was wrong. I dont know where I ...
*November 2, 2010*

**Chemistry**

Use the bond energies given in the "Bond Energy" table (can be gained from google) to estimate the delta Ho for the reaction given below. 2ClF3(g) + 2O2(g) Cl2O(g) + 3OF2(g) I did this: 1530 + 996 - (410 + 570) = 1546. But the answer was wrong. I dont know where I ...
*November 2, 2010*

**Chemistry- helpp!**

The equation for synthesis of the poisonous gas COCl2 is CO(g) + Cl2(g)COCl2 If 43.2 kJ of energy is evolved when 39.5 g of COCl2 is synthesized, what is the molar enthalpy for this synthesis? THANK YOU!
*November 2, 2010*

**Chemistry**

Calculation of the sodium chloride (NaCl) content and evaporation: 1. The amount of sodium chloride in the original mixture may be determined indirectly by adding the masses of ammonium chloride and sand together and subtracting the sum from the initial sample mass of 10g. 2. ...
*October 23, 2010*

**Chemistry**

I am doing a lab online and have no clue on how to get started with the following questions? Please Help me! 1. Calculate and record the following (in grams): (a) mass of NaCl by subtraction of other components: (b) measured mass of NaCl after boiling away water: 2. Calculate ...
*October 23, 2010*

**chemistry**

What volume (in Liters) of hydrogen must react to form 17.0L of ammonia according to the following balanced equation: N2(g) + 3H2(g) --> 2NH3(g) Ratio from equation is H : NH3 = 3 : 2 = 3/2 : 1 = 17x3/2 : 17 = 25.5 : 17 17 L of hydrogen can you check my work is this right?
*October 17, 2010*

**college chemistry**

so it would be (1)(.0036)=n(.0821)(273)?
*October 17, 2010*

**college chemistry**

A volume of 0.285 L of a gas at STP weighs 0.537 g. Calculate the molar mass of the gas (1)(0.285) = n(0.0821)(273). .0036 is this correct?
*October 17, 2010*

**English**

make 2 words, first one 8 letters and second work 4 letters out of these s l r t n r u p a e s a
*October 17, 2010*

**english**

I'm doing an analysis on a class text and a self chosen related text and one of the things the sheet says to do is to identify and define the context of my related text. What does this mean?
*October 17, 2010*