Total # Posts: 2,334
Is it possible to separate Bi, Cu and Ag from a mixture containing: c(BiO+)=0,08M c(Cu2+)=0,242M c(Ag)=0,106M c(HClO4)=1M Eo Bi = 0,32 V, Eo Cu = 0,337 V, Eo = 0,792 V _______________ Using Nernst equation (E=E°-0,0592/n -logQ) i see it's possible to separate Ag, but ...
January 20, 2016
a trolley of mass 200kg is travelling north at 2m\s. It collides head on with a second trolley of mass 500kg which is travelling south with a velocity of 5 m\s and they remain coupled together. a)calculate the velocity of the two trolleys after collision. b)what is the ...
January 18, 2016
Calculate pH and concentration of H2SO3, H2SO3- and SO32- in NaHSO3 c=0,05M. Ka1= 1,23*10^(-2) Ka2= 6,6*10^(-8) Results attached are: a) [H2SO3]= 1,04x10-4 M, [SO32-]=1,3x10-4 M, [HSO3-]= 0,05 M but i keep getting different numbers.
January 7, 2016
Enter the formulae of the products and give their states. Type your answer using the format Na2SO4(aq) for Na2SO4(aq). Do not balance the equation. If there are no products, enter "none". ZnCO3(s) + heat ---> I know it's a decomposition reaction, so I thought ...
December 24, 2015
An object of mass m attached to a spring of force constant k oscillates with simple harmonic motion. The maximum displacement from equilibrium is A and the total mechanical energy of the system is E. What is the object's velocity when its potential energy is 2/3E? the ...
December 15, 2015
A large screen at a theater measures 65 feet diagonally. The aspect ratio (width compared to height) of the screen is 21:9. What is the approximate width and height of the screen?
December 6, 2015
A horizontal water pipe goes from a large diameter to a small diameter and then back to the first diameter as shown in the figure below. The level of water (8cm in the larger tube and 4 cm in the constricted tube) in the small vertical tubes provides us with information about ...
December 4, 2015
Please answer ! Answer everything! A right rectangular prism is intersected by a horizontal plane and a vertical plane. The cross section formed by the horizontal plane and the prism is a rectangle with dimensions 8 inches and 12 inches. The cross section formed by teh ...
December 3, 2015
For a short distance , an elephant can run about 24 9/10 miles per hour. A human can run about 27.89 miles per hour over the same distance . How much faster does a human run that an elephant ?
December 1, 2015
To meke a batch of sugar cookies , you need 0.75 cup of sugar and 1/3 cup of butter , among other ingredients. How much more sugar do you need that butter? a) 5/12 cup b) 3/4 cup c) 1/2 cup d) 2/3 cup
December 1, 2015
in one smowstorm there was 3 2/5 inches of snow ,on the ground. In a second strom, 5.65 inches were added to what was already on the ground . How much total snow was on the ground if none melted between storms? a) 2.25 in b) 9.05 in c) 1.66 in d) 5.21 in
December 1, 2015
Two objects of different masses are joined by a light rod. a) Id the moment of inertia about the center of mas the minimum or maximum and why? b) If the two masses are 3kg and 5kg and the length of the rod is 2m, what are the moments of inertia of the system about an axis ...
November 22, 2015
Biology Check answers
1. Which of the following correctly describes the image below? ￼ protein Molecule RNA Molecule amino Acid carboxylic Acid 2. Glucose and fructose are monosaccharides that have the same chemical formula, C6H12O6. However, they do not react...
November 20, 2015
anyone know how to do this and which choice is correct?thank you so much in advance. Use the Henderson-Hasselbalch equation to calculate the pH of a buffer that is 0.350 M acetic acid and 0.250 M sodium acetate. a.4.89 b.4.47 c.4.59 d.none of the above is is not 4.74
November 17, 2015
can some one help me with a few chem questions please. A chunk of iron weighs 4.32 g. a) How many iron atoms are there in this sample? 55.85 g Fe = 1.00 mol Fe = 6.022 x 1023 atoms Fe b) How many moles of iron are there in this sample? 2. . You have a copper bar weighing 71.24...
November 12, 2015
Which of the following processes releases energy to be used by a cell? a phosphate group is added to ATP to form ADP. a phosphate group is removed from ADP to form ATP. a phosphate group is added to ADP to form ATP. a phosphate group is removed from ATP to form ADP. not sure ...
November 9, 2015
A large box has a mass of 500kg and the coefficient of static friction for the box and the floor is 0.45, and the coefficient of kinetic friction is 0.30. a. What is the minimum horizontal force needed to get the box moving? b. If you continue to push with that force, what ...
November 8, 2015
A mystery surprise box is sliding down a ramp at a constant speed. The box has a mass of 55.0kg and the ramp makes a 40.0 angle with the horizontal. What is the coefficient of kinetic friction between the box and the ramp? Please help asap. Thank you.
November 8, 2015
I personally think it's a because art has many different subjects as I've learned in my art class as I've gone through each lesson with art related to math or social studies so I think it is most likely A ;)
November 5, 2015
That's the problem. I was able to get the second part but cannot figure out the top. I have (P + 2.6688)(4.5 - 0.13356) = 144.453 4.366 P - 11.653 = 144.453 P = 35.755 atm but that isn't right.
October 23, 2015
Use the van der Waals equation of state to calculate the pressure of 3.60 mol of NH3 at 489 K in a 4.50-L vessel. Van der Waals constants can be found here. P= Use the ideal gas equation to calculate the pressure under the same conditions. P= I have tried absolutely everything...
October 23, 2015
MATH CHECK PLEASE
Did you even attempt to do the first one? The first one is eight. First, you multiply $0.65 by 5. Then you multiply $2.25 by 5. You subtract the multiple of $2.25, which is 11.25, by the multiple of $3.25, and you'll get eight. Please try next time instead of guessing.
October 19, 2015
An ore contains Fe3O4 and no other iron.The iron in a 39.5-gram sample of the ore is all converted by a series of chemical reactions to Fe2O3. The mass of Fe2O3 is measured to be 26.7 g. What was the mass of Fe3O4 in the sample of ore? Answer in units of g.
October 15, 2015
A salesperson contacts eight potential customers per day. From past experience, we know that the probability of a potential customer making a purchase is .05. b.) What is the probability the salesperson will make exactly two sales in a day? this is what I think the answer is 0...
October 9, 2015
Anna picked 6 cards from these 10 digit cards to form a 6-digit number: 0 1 2 3 4 5 6 7 8 9, then asked Ola to guess what number she made. 1.Only the first digit is an odd number.2.The digit in the ten thousands place is twice the digit in the ones place.3.The number is 800 ...
October 6, 2015
A drone 125 ft high sights a landing pad with an angle of depression of 15 degrees. what is the horizontal distance between the drone and the landing pad? I tried all the methods set it up multiple ways, and I'm at a loss. My teacher said the answer is 466.5ft.. but how? ...
October 5, 2015
A skier speeds down a smooth ski slope which is at an angle of θ = 21° with the horizontal. The mass of the skier is 75 kg. Take the downhill direction to be positive and uphill to be negative. What is the net force acting on the skier? Ok, so I have set up these ...
September 28, 2015
2nd Law Physics
You fashion a sling shot with a rather long and wide rubber band and practice hurling pebbles. You pull back on the center of the band with a force of 2.31 N. The angle between the two halves is 107°. What is the tension in the band? I get the gist of setting up Newton'...
September 28, 2015
Calculate the standard heat of reaction at 250C (298K) and 1 atm pressure of 3FeO(s) + 2Al(s) → Al2O3(s) + 3Fe(s) in terms of per mole of Al2O3 formed, per mole of Fe formed, per mole of FeO reacted, per mole of Al reacted and per g of Fe formed. ΔH298K,FeO(s) = -63...
September 27, 2015
A mover has to move a heavy sofa of mass 146 kg to the second floor of the house. He uses a rope to pull the sofa up a ramp from the first to the second floor. As he pulls the sofa he makes sure that the rope is parallel to the surface of the ramp which is at 30.0° to the ...
September 27, 2015
You are given a recipe for a buffer that contains 5% (w/v) MgSO4.7H2O. However, you only have MgSO4 anhydrous available to you. How much MgSO4 anhydrous do you need to make 0.5L of the buffer with the same molar concentration as in the recipe? Show your calculations
September 16, 2015
A 10.0 microCoulomb point charge is fixed in place at the origin. A 2.00-microCoulomb point charge is released from rest at x = 0.500 m. Because of the repulsive force between the two point charges, the 2.00-microCoulomb charge is accelerated in the +x direction. What is the ...
September 15, 2015
Hi! Can you please check if my answers are correct? And, can you please tell me any other details you think are important to add. Also, the last two questions i have no clue how to answer. can you help? thanks so much! 3.A burning candle produces a luminous flame. What is the ...
September 11, 2015
I'm having trouble turning mM to mOsmoles. The equation goes like this: red blood cell are placed into a beaker filled with .5L of a 150mM NACL solution. NACL is non-penetrating solute and will not cross the red blood cell membrane. I have 150mM/0.5L * 2mOsM/100mM But ...
September 8, 2015
A constant force of friction of 50 N is acting on a body of mass 200kg moving initially with a speed of 15m/s. How long does the body take to stop? What distance will it cover before coming to rest?
July 30, 2015
Intro to Algebra- Geometry
A sail on a sailboat has a base of 10 ft. and a height of 18 ft. and needs to be sealed with water repellent. One can of water repellent will cover 50 sq. ft., how many cans will be needed to cover the sail?
July 28, 2015
Probability and statistics
The hydrocarbon emissions at idling speed in parts of million (ppm) for automobiles of 1980 and 1990 model years are given for 20 randomly selected cars. 1980 models: 141 359 247 940 882 494 306 210 105 880 200 223 188 940 241 190 300 435 241 380. 1990 models: 140 160 20 20 ...
July 20, 2015
1) Microscopic hairs of the windpipe are always __________. 2) The cilia of the windpipe move harmful substances __________. 3) You build a heavy gust of air when you __________ or __________. 4) Coughing and sneezing help push harmful substances from the __________.
July 15, 2015
I am writing a 300 word short story(or a "'personal' narrative essay") for the prompt: lessons we learn affect one's future. So far I have a general idea: I want the lesson to be loyalty and truth and I want the effect to be that the character would learn...
June 21, 2015