Sunday

May 1, 2016
Total # Posts: 1,681

**Chemistry**

If calcium carbide has a standard enthalpy of formation of -59.8 kJ/mol and acetylene has a standard enthalpy of formation of 226.73 kJ/mol, what is the standard enthalpy change for the reaction?
*February 20, 2013*

**math**

The supplement of angle z is 120 degrees what is the complement of angle z?
*February 20, 2013*

**CALCULUS**

FIND THE DERIVATIVE OF THE FUNCTION f (x) = 10e^x
*February 20, 2013*

**CALCULUS**

FIND THE DERIVATIVE OF THE FUNCTION f (x) = 10e^x
*February 20, 2013*

**organic chem**

Why are we deprotonating the carboxylic acid that is initially dissolved in the dichloromethane? By deprotonating the carboxylic acid, it becomes soluble in the aqueous HCl extracting layer. By deprotonating the carboxylic acid, it becomes soluble in the aqueous NaOH ...
*February 15, 2013*

**english **

right now people who cant breathe (or read warnings)are bumming cigarettes. what message or important comment does the right now comment appear to be making?
*February 13, 2013*

**statistics**

The mean scale score on the mathematics examinatin of ninth graders in Texas was 86 with a standard deviation of 5 points. Given a student was selected at random what is the probability tht his score was 91 or higher
*February 10, 2013*

**statistics**

The mean scale score on the mathematics examinatin of ninth graders in Texas was 86 with a standard deviation of 5 points. Given a student was selected at random what is the probability tht his score was 91 or higher
*February 10, 2013*

**statistics**

The mean scale score on the mathematics examinatin of ninth graders in Texas was 86 with a standard deviation of 5 points. Given a student was selected at random what is the probability tht his score was 91 or higher
*February 10, 2013*

**statistics**

the mean scale score on the mathematics examination of ninth grade students in new york state was 86 with a standard deviation of 5 points. Given a student was selected at random what is the probabilty that his score was 91 or higher?
*February 9, 2013*

**stats**

Why must you square the deviation scores when computing a standard deviation using the definitional formula? Why is the computational formula easier to use when computing variance and standard deviation?
*February 5, 2013*

**stats **

Relatively speaking, which statistics exam did you do better on? On your first statistics exam you scored a 72 and on the second exam you scored an 89. Hey, you’re improving! Or are you? On the first exam, the class mean was 71 with a standard deviation of 15. On the ...
*February 5, 2013*

**Calculator Question**

(ln2)/(5 ln2+ln7) and get 0.128
*February 4, 2013*

**Chemistry**

Sorry for asking such simple question. Why we must assume like that? And why not the Kp= [HI]^2/[H2][I2]?Yet you put 2 in front of HI. Typo?
*February 1, 2013*

**Chemistry**

Its helps a lot...btw are you assuming Kp=Kc?
*February 1, 2013*

**Chemistry**

i don't understand bobpursley..how is it actually?
*February 1, 2013*

**Chemistry**

At 400°C the reaction H2+I2<->2HI has an equilibrium constant Kp value of 55.5. A mixture of 1 mole of H2 and 1 mole of I2 is placed in a flask and heated to 400°C. Calculate the mole fraction of HI in the mixture of gases when equilibrium reached.
*February 1, 2013*

**Math**

How do i write one thousand six and six tenths
*January 30, 2013*

**English**

Last one. The story ended very happily. Adverbs very and happily or only Very?
*January 28, 2013*

**English**

How about this one? The summer rain fell extremely heavily. Are extremely and heavily both adverbs that describe fell?
*January 28, 2013*

**English**

What are the adverb(s) in the following sentence The teacher seemed unusually cheerful. Is it unusually and cheerful?
*January 28, 2013*

**physical science**

If you dissolve 25.0g og sugar in 150cubic cm of water, what is the concentration in g/cm3 g/10cm3 g/10cm3
*January 19, 2013*

**Trig**

A 12-foot ladder reaches 9 ft 6 in up a wall. How far up would a 20-foot ladder reach when placed at the same angle? Write the answer in feet with inches.
*January 17, 2013*

**math**

60%
*January 15, 2013*

**chemistry**

which is more endothermic in water, ammonium chloride or potassium nitrate
*January 13, 2013*

**Math**

If a road passes through R(4,-11) and S (0, -9) and another road passes through J (6,-2) and K(4, -5) and are straight lines, are the two roads perpendicular and why?
*January 10, 2013*

**math**

(parent). My son's problem says "the product of a number and 17"...supposed to write as expression... I'm thinking it would be a 17x=y but he's adamant that because the word "and" is in the sentence that he needs to add something as well.... (no...
*January 8, 2013*

**math**

use the properties of logarthms to find the exact value of the each expression lower 7loglower 76
*January 7, 2013*

**statistics**

At a large dept. store, the avg. number of years of employment for a cashier is 5.7 with a standard deviation of 1.8 years. If the number of years of employment at this department store is normally distributed, what is the probability that a cashier selected at random has ...
*January 4, 2013*

**statistics**

A food snack manu. samples 15 bags of pretzels off the assembly line and weighed their contents. If the sample mean is 10.0 and the sample standard deviation is .15, find the 95% confidence interval estimate for the true mean.
*January 3, 2013*

**science**

A normal man and a heterozygous color blind "carrier" woman have a baby. If they have a girl, what is the probability that the girl will be colorblind. If they have a boy, what is the probability that the boy will be colorblind?
*December 18, 2012*

**psychology**

Marla is talking to a friend and spreading a rumor that she heard about a co-worker. When the friend asks where she heard the rumor, Marla cannot remember. Marla is experiencing what psychologists call 1)retrograde amnesia. 2)anterograde amnesia. 3)source amnesia. 4)stress ...
*December 9, 2012*

**psychology**

Recent neuroimaging research indicates that people with OCD show increased levels of grey matter in the _____ and the _____ relative to those who do not have OCD. 1)splenium; corpus collosum 2)locus ceruleus; hypothalamus 3)thalamus; left frontal cortex 4)thalamus; right ...
*December 9, 2012*

**Physics**

a mouse pushes a piece of cheese with a mass of 6.4 g for a distance of 75 cm over the frictionless surface of an air hockey table. He exerts a constant 0.5 N force as he does so. If the cheese starts from rest, what is it's final velocity?
*December 5, 2012*

**Physics**

three bugs that are connected by a mass less spider silk are pulled along a frictionless table top. The first bug has a mass of 1.5 g, the second, 2.0 g, and the third, .75 g. The spider pulling them exerts a force of 0.011 N. What is the acceleration of each bug?
*December 5, 2012*

**chemistry**

need to convert 5.26g/cm3 to m3
*December 2, 2012*

**science**

Mendel realized that the principles of probability could be used to _______ the results of genetic crosses. What's the blank? please help! thanks a bunch!
*November 27, 2012*

**physics**

A 1500kg car is approaching the hill shown in the figure at 15.0 m/s when it suddenly runs out of gas. Part A What is the car's speed after coasting down the other side?
*November 26, 2012*

**physics**

a 1100 kg wrecking ball hangs from a16m long cable. the ball is pulled back until the cable makes an angle of 17 with the vertical. By how much has the gravitational potential energy of the ball changed?
*November 26, 2012*

**hum 101**

What are some examples of a situation that the strateigies used in "The Art of The War by Sun Tzu be applied to?
*November 23, 2012*

**chemistry**

44.5
*November 20, 2012*

**4th grade math**

What is 15,454 rounded to the nearest thousand?
*November 15, 2012*

**Chemistry**

Iron (III) hydroxide is soluble in acid: Fe(OH)3(s)3H^+(aq)-->Fe^3^+(aq)+3H2O(l) a. How many milliliters of 1.00 M HCl are needed to dissolve 1.00 g of iron (III) hydroxide? b. If you added enough HCl to dissolve the 1.00 g of iron (III) hydroxide and then diluted the ...
*November 11, 2012*

**Physics**

A 11.0-g bullet is fired horizontally into a 101-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 160 N/m. The bullet becomes embedded in the block. If the bullet-block system compresses the spring ...
*November 11, 2012*

**chemistry**

_A2(SO3)3+_NaOH->_Na2SO3+_Al(OH)3 if you start with 389.4 g of Al2(SO3)3 and you produce 212.4 g of Na2SO3, what is your percent yield for this reaction?
*November 10, 2012*

**chemistry**

_H3PO4+_KOH->_K3PO4+_H2O if 49.0 g of H3PO4 is reacted with excess KOH, determind the percent yield of K3PO4 if you produce 49.0 g of K3PO4.
*November 10, 2012*

**chemistry**

1K2PtCl4+2(NH3)->1Pt(NH3)2Cl2+2KCl what is the percent yield, when 34.5 grams of NH3 react with excess K2PtCl4 if 76.4 g of Pt(NH3)2Cl2 are actually produced?
*November 10, 2012*

**Calculus**

what happens to the 2 in e^2x? do u bring it down?
*November 9, 2012*

**Calculus**

Find the solutions of the exponential equation e^2x–4e^x+3=0 x1=? x2=?
*November 9, 2012*

**physics**

While fishing, you get bored and start to swing a sinker weight around in a circle below you on a 0.31- piece of fishing line. The weight makes a complete circle every 0.70 . What is the angle that the fishing line makes with the vertical? Express your answer using two ...
*November 7, 2012*

**Chemistry**

a 9.85 g sample of an unknown metal M is burned in the presence of excess oxygen, producing the oxide M2O3 (s) and liberating 57.8kJ of heat at constant pressure. What is the identity of the metal? 4M(s) + 3O2(g) yields 2M2O3(s)
*November 4, 2012*

**Calculus **

Let f(x) = 1/(x+2) and g(x)= (x-1)/x. Simplify and state the domain. f(g(x)) g(f(x))
*October 29, 2012*

**Poem Help**

so the correct answers for this quick check, which I just took, are: 1. b 2. c 3. a 4. d
*October 29, 2012*

**Poem Help**

4 is d
*October 29, 2012*

**calculus**

lim (x^(2)-4)/(x-2) x->2 lim x->1 (x+1)/(x-1)
*October 27, 2012*

**Chemistry**

Running at a rate of 6 mi/h uses 704 Calories in an hour. Convert this value to (a) calories; (b) kilocalories; (c) joules; (d) kilojoules.
*October 25, 2012*

**math**

The products of 5x4 (20) and 1x4 (4)added together (20+4=24)is one half the product of 6x8 (48). If you double the sum of 20+4 (24) you will get 48 (24+24=48 or 24x2+48).
*October 23, 2012*

**Programming Logic **

Shemrock Inc. is a brake pad manufacturing company. This company uses raw materials, such as carbon powder, iron, ash, and resin. It wants to develop an inventory management system that will have the following features: 1.The system should store the current inventory levels ...
*October 23, 2012*

**chemistry**

Complete and balance the molecular equation, including phases, for the reaction of aqueous ammonium bromide, NH4Br, and aqueous lead(II) acetate, Pb(C2H3O2). Enter the balanced net ionic equation, including phases, for this reaction.
*October 23, 2012*

**chemistry**

A certain weak base has a Kb of 9.00 × 10-7. What concentration of this base will produce a pH of 10.34?
*October 21, 2012*

**lens surface**

A spherical generator is used to produce a -15.00D surface on glass of refractive index 1.80. The diameter of the cutting tool is 80mm and the radius of the cutting surface is 4mm. What is the angle between the axis of the tool and the axis of the lens? Do I calculate the ...
*October 18, 2012*

**Chemistry**

What is the concentration of Cu2+ in a solution that is 0.10 M Cu(NH3)4^2+? (Kf = 1.2 x 10^12) The answer is 8.0 x 10^-4 How do I solve the problem to get the answer
*October 14, 2012*

**physics**

If an automobile engine delivers 48.2 hp of power, how much time will it take for the engine to do 6.80 ✕ 105 J of work? (Hint: Note that one horsepower, 1 hp, is equal to 746 watts.)
*October 12, 2012*

**Physics**

A dockworker loading crates on a ship finds that a 22-kg crate, initially at rest on a horizontal surface, requires a 80-N horizontal force to set it in motion. However, after the crate is in motion, a horizontal force of 59 N is required to keep it moving with a constant ...
*October 9, 2012*

**Physics**

A dockworker loading crates on a ship finds that a 22-kg crate, initially at rest on a horizontal surface, requires a 80-N horizontal force to set it in motion. However, after the crate is in motion, a horizontal force of 59 N is required to keep it moving with a constant ...
*October 9, 2012*

**Physics**

A crate of mass m = 31 kg rides on the bed of a truck attached by a cord to the back of the cab as in the figure. The cord can withstand a maximum tension of 82 N before breaking. Neglecting friction between the crate and truck bed, find the maximum acceleration the truck can ...
*October 9, 2012*

**physics**

Betty Bodycheck (mB = 51.4 kg, vB = 22.0 km/h in the positive x-direction) and Sally Slasher (mS = 42.4 kg, vS = 28.0 km/h in the positive y-direction) are both racing to get to a hockey puck. Immediately after the collision, Betty is heading in a direction that is 76.0° ...
*October 8, 2012*

**please help!**

I'm having trouble with this word problem. Two friends Jodi and Abe go horseback riding on the same trail in the same direction. Jodi's horse travels at 5 miles per hour while Abes horse travels at a slower pace. After 2 hours they are 2 miles apart. Find Abes horse ...
*October 5, 2012*

**math**

to estimate how many more people live in Atherton than Needles, which is closer to the exact answer: rounding to nearest hundreds or thousand
*October 4, 2012*

**Is this right? **

I have to determine the slope and y- intercept of this equation then graph 4x=6y+9 so I ended up putting it in y-mx+b form and it was 6y=4x+9 so slope is 4x and y intercept is 6y? How would I graph it though?
*October 3, 2012*

**math**

use the orden of operation and the digit 4 four time to write problems that have the following answers 44
*October 1, 2012*

**Math**

Expression for the square of one more than a number
*October 1, 2012*

**Math**

-8(t-3)-(t+1)=6
*September 24, 2012*

**Physics**

A baseball is hit so that it travels straight upward after being struck by the bat. A fan observes that it takes 3.20 s for the ball to reach its maximum height.
*September 21, 2012*

**Physics**

A ball is thrown vertically upward with a speed of 15.0 m/s. (a) How high does it rise? (b) How long does it take to reach its highest point? (c) How long does the ball take to hit the ground after it reaches its highest point? (d) What is its velocity when it returns to the ...
*September 21, 2012*

**Physics**

In 1865, Jules Verne proposed sending men to the Moon by firing a space capsule from a 220-m-long cannon with final speed of 10.97 km/s. What would have been the unrealistically large acceleration experienced by the space travelers during their launch? (A human can stand an ...
*September 21, 2012*

**Physics**

A steam catapult launches a jet aircraft from the aircraft carrier John C. Stennis, giving it a speed of 205 mi/h in 3.00 s. (a) Find the average acceleration of the plane. (b) Assuming the acceleration is constant, find the distance the plane moves.
*September 21, 2012*

**Physics**

The average person passes out at an acceleration of 7g (that is, seven times the gravitational acceleration on Earth). Suppose a car is designed to accelerate at this rate. How much time would be required for the car to accelerate from rest to 59.1 miles per hour?
*September 20, 2012*

**Physics**

A tortoise can run with a speed of 0.13 m/s, and a hare can run 20 times as fast. In a race, they both start at the same time, but the hare stops to rest for 4.0 minutes. The tortoise wins by a shell (35 cm). (a) How long does the race take? (b) What is the length of the race?
*September 20, 2012*

**Physics**

A motorist drives north for 40.0 minutes at 61.5 km/h and then stops for 15.0 minutes. He then continues north, traveling 130 km in 1.70 h. (a) What is his total displacement? (b) What is his average velocity?
*September 20, 2012*

**health**

i think its B.
*September 18, 2012*

**Math**

1.d 2.a 3.c 4.b
*September 13, 2012*

**science**

I need helping locating information about the environment of Costa Rica so that I can analyze data about the country.
*September 9, 2012*

**HSM/270**

Last few weeks of class and struggling to keep up to graduate, can somebody help me if they have done this before, also i used the PEACE Program for my assignments in this Grant Proposal and Writing class. Thanks Identify where the program planning and evaluation process can ...
*September 8, 2012*

**english**

Was this answer correct?
*September 7, 2012*

**math**

What are the step to help solve for 5r+30/20= 3r-36/3
*September 7, 2012*

**math**

How to write the ration as a fraction in lowest terms. Compare in hours. 22 hours to 3 days. The ratio is __.
*September 7, 2012*

**math**

The distance between city A and city B is 500 miles. On a certain wall map, this is represented by a length of 2.3 feet. On the map, how many feet would there be between city C and city D, two cities that are actually 800 miles apart? On the map, city C and city D are ___ feet...
*September 7, 2012*

**math **

If 5 sweaters cost $39.40, how much would 8 sweaters cost? The cost is $__.
*September 7, 2012*

**math**

Write the ratio as a fraction in lowest terms. compare in inches. 3ft to 31 inches. The ratio is__.
*September 7, 2012*

**math **

The sum of the measures of the angles of any triangle is 180 degrees. In triangle abc, angles a and b have the same measure, while the measure of angle c is 78 degrees larger than each of a and b. What are the measures of the three angles? angle a is __degrees.
*September 7, 2012*

**math **

If planet I is 31.8 million miles from the sun than planet II, then planet III is 25.6 million miles father from the sun than planet I. When the total of the distances for these three planets from the sun is 200.2 million miles, how far away from the sun is planet II? Planet ...
*September 7, 2012*

**math**

An electrician cuts a 26ft piece of wire into two pieces. One piece is 4ft longer than the other. How long are the pieces? What is the length of the shorter piece?__ft
*September 7, 2012*

**Comunication Skills**

Cultural history.
*September 7, 2012*

**Math**

Evaulate each expression: (-1/8)^1/3 Would you make it 3 square root of -1/8? I don't know how to go from there. (256/81)^1/4 Same thing, would it become 4 square root (256/81)?
*September 6, 2012*

**Math**

Factor out the common factor: −3x^4 y^2 + 18xy^3 + 9xy^4
*September 5, 2012*

**Math**

Factor the trinomial: 2x^2 +11x - 63
*September 5, 2012*

**ENGLISH**

yup! all were right! thanks so much!!:)
*September 5, 2012*