Posts by Jake
Total # Posts: 2,304

Chemistry
A solution of formic acid 0.20 M has a pH of 5.0. What is its Ka value? a) 5.0 x 1010 b) 1.0 x 105 c) 5.0 x 105 d) 25 
Chemistry
Mols benzoic acid = 12.2g/122.12g = 0.0999 Int. Concentration of Benzoic acid = 0.0999 mol/ 0.500L = 0.1998 M Ka = 6.3 x 105 = (x)(x)/0.1998 – x X = [H+] = * M pH = log(*) = * Sorry, this question is just really confusing me.. 
Chemistry
Thanks so much, you're an awesome help. 
Chemistry
Mols benzoic acid = 12.2g/122.12g = 0.0999 Int. Concentration of Benzoic acid = 0.0999 mol/ 0.500L = 0.1998 M Ka = 6.3 x 105 = (x)(x)/0.1998 – x X = [H+] = * M pH = log(*) = * Sorry, this question is just really confusing me.. 
Chemistry
Calculate the pH of a solution prepared by dissolving 12.2 g of benzoic acid in enough water to produce a 500 mL solution. Ka = 6.3 x 10^5 
Chemistry
Can a solution of CrCl3 be stored in an aluminum container? 
Chemistry
Using the following spontaneous reactions, classify the 3 metals involved (Cr, Sn, Al) according to increasing reductant properties. a) 2Cr + 3Sn2+ 2Cr3+ + 3Sn b) Al + Cr3+ Al3+ + Cr 
Chemistry
Which pair of ions will be most likely to react at standard state conditions? 1. a) MnO4 and Sn2+ 2. b) Zn2+ and Cl 3. c) I and Cu 4. d) Fe3+ and Cu2+ 
Chemistry
If a piece of copper metal is dipped into a solution containing Cr3+ ions, what will happen? Explain with Ev values 
Chemistry
Pb(NO3)2(aq) 2 x 103 M Na2SO4(aq) 2 x 103 M Pb(NO3)2(aq) + NaSO4(aq) → PbSO4(s)+ 2NaNO3(aq) a) What are the concentrations of each ion within this solution? b) If 1L of each solution is mixed; will a precipitate form? why? 
Spanish8th grade Help!
Thank you I think what I put is right I've rechecked it but it seems so odd the way I have it.I know it's a reflexive so maybe it is correct. 
Soanish8th grade Help!
I'm trying to conjugate this in the past tense tú/presentarse would I conjugate it in past tense like this (tú te presentaste) Something looks wrong with it 
math
what is the first step in solving the equation x/5  9=6? 
Physics Help
So is there no shift? and if so why is that the case? 
Physics Help
If we witness events taking place on the moon, where gravitation is weaker than on Earth, would we expect to see a gravitational red shift or a gravitational blue shift? and Explain please a)blue shift b)red shift c)no shift 
Chemistry
The following reaction has a Delta G value of 42.6 kJ/mol at 25oC: HB(aq) +H2O(l) > H3O+(aq) +B(aq) Calculate Ka for the acid HB. 
Physics Help!!
Comparing Einstein's and Newton's theories of gravitation, can the correspondence principle be applied? and Why or Why not? a)Yes b)No 
Physics Help please
If we witness events taking place on the moon, where gravitation is weaker than on Earth, would we expect to see a gravitational red shift or a gravitational blue shift? and Explain please a)blue shift b)red shift c)no shift 
Chemisttry
A 100.0mL sample of 0.250 M aniline (C6H5NH2) is titrated with 0.500 M HCl. What is the pH at the equivalence point? 
Chemistry
You take 326 g of a solid (melting point = 57.6oC, enthalpy of fusion = 346 J/g) and let it melt in 757 g of water, and the water temperature decreases from its initial temperature to 57.6oC. Calculate the initial temperature of the water. (Note that the speciﬁc heat ... 
Physics Help!!
A passenger on an interplanetary express bus traveling at v = 0.94c takes a sevenminute catnap by his watch. How long does the nap last from your vantage point on a fixed planet? 
Physics Help please
A bus moving with speed 0.93c is 65 feet long according to its passengers and driver. What is its length from your vantage point on a fixed planet? 
Chemistry
Thanks it worked perfectly 
Chemistry
there isnt a kp or a kc 
Chemistry
Nitrogen gas (N2) reacts with hydrogen gas (H2) to form ammonia (NH3). At 200 oC in a closed container, 1.1 atm of nitrogen gas is mixed with 2.1 atm of hydrogen gas in an otherwise empty container. At equilibrium, the total pressure is 2.2 atm. Calculate the partial pressure ... 
Physics!!
Green light is emitted when electrons in a substance make a particular energylevel transition. If blue light were instead emitted from the same substance, would it correspond to a greater or lesser change of energy in the atom? and why? 
calculus
what is the integer values of n that satisfies this inequality 5<3n<12? Please answer :) 
chemistry
Gaseous butane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 16.9 g of butane is mixed with 39. g of oxygen. Calculate the minimum mass of butane that could be left over by the chemical reaction. Round your answer to 2 significant... 
chemistry
Gaseous butane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 16.9 g of butane is mixed with 39. g of oxygen. Calculate the minimum mass of butane that could be left over by the chemical reaction. Round your answer to 2 significant... 
math
if you invest 500 dollars in a savings account that pays 8% interest per year, compounded quarterly, how much will you have in the account at the end of 11.6 years? 
statistics
What type of statistical information would I include in my report to determine our yeartodate performance of our division; example, mean, median, or standard deviation. 
Life orientation
It damages communities 
Math
In an election, ethan got 5 fewer votes than christohper,who got 3 more votes than olivia, who got 4 fewer votes than Ava. How many more votes did ava get than ethan ? 
math
Given P(x) = x^3  3x^2  5x + 10 a evaluate P9x) for each integer value of x from 3 through 5 b. Prove that 5 is an upper bound on the zeros of P(x) 
Physics
Two masses, m1=3kg and m2=2kg, are suspended with a massless rope over a pulley of mass M = 10kg. The pulley turns without friction and may be modeled as a uniform disk of radius R=.1m. You may neglect the size of the masses. The rope does not slip on the pulley. The system ... 
Calculus
Suppose vectors a and b are vectors such that a x b =(3,1,4). What is the cross product of twice of a with twice of b? 
Calculus/Physics Please help!!
An intravenous line provides a continuous flow of drug directly into the blood. Assuming no initial drug in the blood, the amount of drug in the blood t hours after the dosing begins in m(t)  (a/k)(1e^kt), for t (=>)0, where k is the rate constant (again related to half ... 
CALCULUS PLEASE HELP!!
suppose m(0) milligrams of a drug are put in the blood of an injection. The amount of drug t hours after the injection is given by m(t)=m(o)e^kt, for t (=>) 0, where k is the rate constant, which is related to the half life. we also treat oral administration of drugs as an... 
Calculus
Could someone please explain on how to do this question stepbystep. Thank you! A bolt is being loosened by a 40 cm wrench. The torque in this situation has a magnitude of 12 J and the force makes an angle of 60 degree with the wrench. What is the magnitude of the force used ... 
math
What time would you use to measure the time it takes to travel from your house to New York 
CALCULUS PLEASE HELP!!
suppose m(0) milligrams of a drug are put in the blood of an injection. The amount of drug t hours after the injection is given by m(t)=m(o)e^kt, for t (=>) 0, where k is the rate constant, which is related to the half life. we also treat oral administration of drugs as an... 
Calculas
suppose m(0) milligrams of a drug are put in the blood of an injection. The amount of drug t hours after the injection is given by m(t)=m(o)e^kt, for t (=>) 0, where k is the rate constant, which is related to the half life. we also treat oral administration of drugs as an... 
Calculus
I checked in the book answer and the site u gave me matched with the answer. How did the website get solutions as: x= 3.28183 x= 1.863 
Calculus
Use the algorithm for curve sketching to sketch the graph of each function. a) f(x) 4x^3+6x^224x2 1. First to find intercepts y=0 0=4x^3+6x^224x2 =2(2x^3+3x^312x1) I don't know how to find the xintercept. I can't use quadratic formula or synthetic division :S 
Math help
So do I draw lines through the vertices? 
Math help
Sketch the graph: (x+2)^2/25(y+4)^2/25=1 I don't understand this at all! When I tried graphing it I just had two lines going through the center, which is (2,4). But it should be a hyperbola, right? Could anyone help me? 
World History
During the Columbian Exchange what diseases were brought from the new world to Europe? 
HELP PLEASE PHYSICS!!
Thank you!!! 
HELP PLEASE PHYSICS!!
How much does it cost to operate a 100 W lamp continuously for 1 week if the power utility rate is 8/kWh? answer in $ 
Physics Need Help PLEASE
okay great!!! Thank you again!!!! you do a wonderful job!!!! 
Physics Need Help PLEASE
its looking for the N/C I got 4*10^21 but I'm not getting it correct 
Physics Need Help PLEASE
Thank you so much Elena that helped me out a lot! I was wondering if you could also help me with another question. A droplet of ink in an industrial inkjet printer carries a charge of 6 1013 C and is deflected onto paper by a force of 2.4 107 N. Find the strength of the ... 
Physics Need Help PLEASE
Two point charges are separated by 8 cm. The attractive force between them is 14 N. If the two charges attracting each other have equal magnitude, what is the magnitude of each charge? 
math
2/3Y + 1/6 Y+ Y= 
Calculus
Which plane goes through the origin and is perpendicular to the line r=(2,2,1) + s(2,3,4), seR? a) 2x2y+z=0 b) 2x+3y4z=0 c) 2x+3y+z4=0 d) none of the above. I got D, none of the above. I have substituted and couldn't find the answer equal to zero. 
Calculus
Are the points P(1,2), Q(7,3) and R(2,1) o the line with vector equation r=(19,5) +s(6,1), SeR 
Calculus
which pair of lines are perpendicular? a) 2x + 3y  7=0, 3x  2y + 2=0 b) 2x  3y + 2=0, 5x  7y + 2=0 c) 4x + y  3=0, x + 4y=0 d) 5x + y + 1=0, 5x + y + 1=0 Please explain. I know we have to use the dot product :3 
engineering mechanics
14 degrees 
Calculus
A rusted bolt requires 30 J of torque to be loosened. If only 40 N of force is applied to a wrench with which it makes a 90° angle, how long is wrench? 
Calculus
Determine the value(s) of k such that the area of the parallelogram formed by vectors a = (k+1, 1,2) and b =(k,3,0) is [sqrt(41)] 
Calculus
For which value(s) of k will the dot product of the vectors (k,2k1, 3) and (k,5,4) be 7? I did this so far, 2k1=5 6/2 k=3 
College Chemistry
Write three equations (including ΔH values) that represent the heats of formation for each C6H12O6(s), CO2(g), and H2O(l). (Hint: look up heats of formation for each participant) 
Calculus
Two force vectors act on an object and the dot product of the two vectors is 20. If both of the force vectors are doubled in magnitude, what is their new dot product? 
chemistry
the pH is NOT 1.85 
Calculus
Sorry for the confusion. May I ask why my answer does not work? :S its asking for the vertices, not equal to Point P. 
Calculus
Why add? 
Calculus
I am bit of confused from this question. I have shown the work below and to subtract, am I supposed to be X2  X1, Y2Y1, Z2Z1? or X1X2, Y1Y2, Z1Z2?  A triangle has sides formed by the vectors PA=(2,7,3) and PB=(6,2,2). The point P=(1,3,... 
Physics
A box of mass m=1.5 kg is attached to a spring with force constant k=12 and suspended on a frictionless incline that makes a 30 degree angle with respect to the horizontal. With the spring in its unstretched length, the box is released from rest at x=0. The box slides down the... 
Calculus
I am bit of confused from this question. I have shown the work below and to subtract, am I supposed to be X2  X1, Y2Y1, Z2Z1? or X1X2, Y1Y2, Z1Z2?  A triangle has sides formed by the vectors PA=(2,7,3) and PB=(6,2,2). The point P=(1,3,... 
Calculus
1. Which of the following sets of vectors spans [r^2] ? a) {(1,1), (2,2)} b) {(1,1), (1,2)} c) {(1,2), (1/2,2)} d) {(1,1), (1,1)} 2. Which of the following sets of vectors spans [r^3] ? a) {(1,1,1), (2,2,2)} b) {(1,3,1), (2,2,2)} c) {(1,2,1), (1/2,1,1/2)} d) {(1,3,2), (1... 
Calculus
Point A=(1,3,4) and point B=(2,2,0). Determine AB. a) (3,1,4) b) (3,1,4) c) (1,5,4) d) (1,5,4) I chose answer C. 2. A goes from (2,1) to (4,1) Determine the components of A. a) (6,0) b) (2,2) c) (2,2) d) (0,6) 
Calculus
Vector D represents: URL is here imgur dot com/AX4EN a) A+B b) AB c) C+B d) A+C I chose answer A. Is that the correct answer? 
Chemistry
How many moles of nitrogen are needed to produce 1.52 moles of nitrogen (ll) oxide ? N2 + O2 > FeCL3 + 3H20 
Algebra
Use the substitution method to solve x + 3y=24 5x +8y=5 
Calculus and vectors
C=5 and D=8. The angle formed by vectors C and D is 35 degrees, and the angle formed by vectors A and C is 40 degrees. Determine B. Could someone explain this question 
fractions
6/8 pizza left, which can be reduced to 3/4. 
Calculus and vectorsHelp~David
Thank you very much! 
Calculus and vectorsHelp~David
Rectangular prism is defined by vectors (2,0,0)(0,9,5) and (0,0,3). Find the volume. I have done this so far, would anyone please verify this. (2,0,0)(0,9,6) (02, 90, 60) =(2,9,6) (2,9,6)(0,0,3) =(2,9,3) (2)(9)(3)=54 cm^3 Therefore volume is 54 cm^3 
Calculus
Is B=(2,1,6)? 
Calculus
If A=(1,2,4) and Vector A+B =(3,1,2). What is B? 
Calculus and vectors @ Bob Purs
I multipled by 2 since its a rectangle, there is an example of similiar to this question but its a triangle. 
Calculus and vectors @ Bob Purs
Rectangle side is represented by (2,3) and (6,4). Find the perimeter of rectangle. Is this correct? (62), 43) sqrt(8^2+1^2) sqrt(65) =8.062257748(2) =16.124? 
Math
Is this correct? ((62), 43) sqrt(8^2+1^2) sqrt(65) =8.062257748(2) =16.124? 
Math
Rectangle side is represented by (2,3) and (6,4). Find the perimeter of rectangle. Do I have to find the magnitude of (2,3) and (6,4) and square root the answer? 
Calculus
Thank you for answering. Don't I have to find the magnitude then use square root of the answer and multiply by 2? If so, could you show it. 
Calculus
Rectangle side is represented by (2,3) and (6,4). Find the perimeter of rectangle. Could someone please help~ 
Calculus and vectors
Could someone explain to me how I can find the area/perimeter/volume of a rectangular prism if I am given R^3 points. For example find area of rectangular prism given pts (2,3,4)(5,3,2), similar to this. 
math
1.5 
Calculus and vectors
Bob can swim at a rate of 5km/h. He is in a river that is flowing at a rate of 9 km/h. a) if bob swims upstream, what is his relative velocity to the ground? b)if bob swims downstream, what is his relative velocity to the ground? c) Someone decides to help Bob out of the water... 
physics
Bob can swim at a rate of 5km/h. He is in a river that is flowing at a rate of 9 km/h. a) if bob swims upstream, what is his relative velocity to the ground? b)if bob swims downstream, what is his relative velocity to the ground? c) Someone decides to help Bob out of the water... 
Math
Bob can swim at a rate of 5km/h. He is in a river that is flowing at a rate of 9 km/h. a) if bob swims upstream, what is his relative velocity to the ground? b)if bob swims downstream, what is his relative velocity to the ground? c) Someone decides to help Bob out of the water... 
Chemistry
Why doesn't water undergo electrolysis? Why does Na2SO4 undergo electrolysis? 
trig
verify that 2/1+cos theta  tan squared (theta/2) = 1 
Math
Multiplying a vector by a scalar results in: a) a scalar b) a perpendicular vector c) a collinear vector c) a parallel scalar 
Math
Sabrina and John cut a pie into 4 slices. Sabrina eats 2 slices. John eats the rest. What fraction names the part of the pie that John eats? 
Biology
Among humans, increased interest in food intake normally occurs _____. only after the production of glucose in the liver can no longer meet metabolic needs when fewer calories are taken in than are expended, but only after the body depletes its reserves of fat in the liver via... 
SCIENCE/ earth
Thanks Ms Sue!!! 
SCIENCE/ earth
plate tectonics crossword puzzle what Qs and As can i use??????? PLZZZZZ HELP ME!!!!!!!!!!!!! 
PHYSICS
A space explorer is 4.6 billion km away from a certain star, and observes that the gravitational force of attraction exerted on the spacecraft by the star is 500 N. What will the force become when the craft has approached to a position 2 billion km from the star? 
PHYSICS
Determine the value for the acceleration due to gravity at the surface of the planet Mars, given the following data: Mass of Mars = 6 .42 x 10^23 kg Radius of Mars = 3.37 x 10^6 m Thanks!