# K

Popular questions and responses by K-
## Chemistry (Dr.Bob222)

The generic equation: Base− + H2O -> HBase+ OH− can be used to account for the pH of which salt? 1)CaI2 2)NH3 3)KCN 4)Al(NO3)3 5)NaCl Ok, so I know NH3, won't work because it is not a salt. The answer is KCN, but I don't understand why, could you

*asked on November 2, 2013* -
## CHEM

Which statement best describes the polarity of SF_4Cl_2?? (or: SF4Cl2, if that helps more) 1. Always polar. 2. Always nonpolar. 3. Depending on the arrangement of outer atoms, this molecule could be polar or nonpolar. & how can you tell for certain??? I

*asked on November 26, 2007* -
## CHEM

What are the expected bond angles in ICl4+ (or) ICl_4^+ ?? I think that I have the stucture drawn correcty: I is the central atom with one lone pair above it. I then have the Cl's with 6dots around them & then bonded, singly, to the "I". Two "Cl's" go

*asked on November 26, 2007* -
## CHEM

Help on part "c": The forensic technician at a crime scene has just prepared a luminol stock solution by adding 19.0g of luminol into a total volume of 75.0mL of H2O. a)What is the molarity of the stock solution of luminol? anwer I got: molarity of luminol

*asked on October 18, 2007* -
## Chemistry

The Hydrolysis Reactions - Write net-ionic equations for the reaction of each salt with water below. If there is no reaction, write N.R. 1. NH4C2H3O2 2. NH4Cl 3. NaCl 4. Na2CO3 5. NaC2H3O2 6. NaHSO4 7. FeCl3 8. NaH2PO4 9. NaHCO3

*asked on April 30, 2011* -
## CHEM

For a molecule of fluorous acid, the atoms are arranged as HOFO. What is the formal charge on each of the atoms? Enter the formal charges in the same order as the atoms are listed. For this question I tried entering: +1,-2,+3,-2 and it was wrong...as was:

*asked on November 26, 2007* -
## **CHEM**

Arrange the following elements in order of decreasing atomic radius: Cs, Sb, S, Pb, Se *(list from largest to smallest...or..."the correct ranking cannot be determined") ***I think the answer 'should be', from largest to smallest: ***Cs, Pb, Sb, Se,

*asked on November 13, 2007* -
## CHEM

Which of the following elements has the highest first ionization energy? Element then radius (pm): X = 105pm Y = 175pm Z = 274pm I think that the answer is "Z-274pm", but I just would like to make sure.

*asked on November 13, 2007* -
## math

what prime factor that will equal 98

*asked on August 6, 2020* -
## CHEM-last part prob.

Aluminum reacts with chlorine gas to form aluminum chloride via the following reaction: 2Al(s) + 3Cl2(g) -> 2AlCl3(s) You are given 19.0g of aluminum and 24.0g of chlorine gas. a)If you had excess chlorine, how many moles of of aluminum chloride could be

*asked on October 16, 2007* -
## CHEM

A) a picture shows a container that is sealed at the top by a movable piston. Inside the container is a ideal gas at 1.00atm , 20.0 *C, and 1.00L. (The pic is of a 2L container which has a piston pushed downward to the 1L level. Under the piston, under the

*asked on October 28, 2007* -
## CHEM

The mass of a golf ball is 45.9g. If it leaves the tee with a speed of 72.0 m/s, what is its corresponding wavelength? Express your answer numerically in meters. Would the correct answer be: lambda=h/mv lambda=6.626*10^-34/(45.9g)(72.0m/s)

*asked on November 5, 2007* -
## CHEM

Consider the following neutral electron configurations in which 'n' has a constant value. Which configuration would belong to the element with the most negative electron affinity, E-ea? a) ns^2 b) ns^2 np^2 c) ns^2 np^5 d) ns^2 np^6 would the answer be

*asked on November 13, 2007* -
## CHEM

The electron from a hydrogen atom drops from an excited state into the ground state. When an electron drops into a lower-energy orbital, energy is released in the form of electromagnetic radiation. Part A: How much energy does the electron have initially

*asked on November 4, 2007* -
## CHEM

My balanced equation is: a) 2C8H18(g) + 25O2(g) -> 16CO2(g) + 18H2O(g) b) 0.290 mol of octane is allowed to react with 0.670mol of oxygen. Which is the limiting reactant? (((Which I found Oxygen to be the limiting reactant.))) I do not understant how to

*asked on October 15, 2007* -
## PHYSICS!!!

The Venturi tube shown in the figure below may be used as a fluid flowmeter. Suppose the device is used at a service station to measure the flow rate of gasoline (ñ = 7.00 102 kg/m3) through a hose having an outlet radius of 2.72 cm. The difference in

*asked on November 11, 2012* -
## trig

find the exact value of sin(u+v) given that sin u=3/5 and sin v= 15/17

*asked on December 18, 2011* -
## Chemistry

Determine Kc for the following reaction: 1/2N2(g) + 1/2O2(g)+ 1/2Br(g) NOBr(g) from the following information (at 298K) 2No(g) N2(g) + O2(g) Kc = 2.1x10^30 NO(g) + 1/2Br2(g) NOBr(g) Kc = 1.4

*asked on May 25, 2011* -
## physics

A near-sighted person might correct his vision by wearing diverging lenses with focal length f = 60 cm. When wearing his glasses, he looks not at actual objects but at the virtual images of those objects formed by his glasses. Suppose he looks at a

*asked on January 28, 2013* -
## biology

eye color is not an example of a trait.false

*asked on August 16, 2008* -
## O.CHEM -> PLEASE CHECK!!

Arrange the compounds in the order of increasing boiling point ***(LOWEST first): 1) H3C-O-CH3 2) H2O 3) CH3CH2OH 4) CH3CH2SH I think the order should be: #1, 4, 3, 2 Arrange the following in order of increasing rate of reactivity with conc.HBr ***(LEAST

*asked on March 12, 2008* -
## CHEM

What is the hybridization of the central atom in COH2?? Would the correct response, out of the following: a) sp b) sp^2 c) sp^3 d) sp^3d e) sp^3d^2 "e"-> sp^3d^2??

*asked on November 26, 2007* -
## math

An Artisan has 63 kg of metal of density 7,000kg/m3. He intends to use make a rectangular pipe with external dimensions 12 cm by 15 cm and internal dimensions 10 cm by 12 cm. Calculate the length of the pipe in meters.

*asked on April 14, 2018* -
## chem

Suppose you have two 100-mL graduated cylinders. In each cylinder there is 40.0mL of water. You also have two cubes: one is lead, and the other is aluminum. Each cube measures 2.0cm on each side. After you carefully lower each cube into the water of its

*asked on September 1, 2014* -
## chemistry

The rate constant for this first-order reaction is 0.0570 s–1 at 400 °C. A-->Products After how many seconds will 14.0% of the reactant remain?

*asked on March 23, 2012* -
## CHEM

A cylinder with a movable piston contains 2.00g of helium, He, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the

*asked on October 28, 2007* -
## business math

Oprah Winfrey ha closed on a 42- acre estate near Santa Barbara California for $50,000,000 If Oprah puts down 20% down and finances at 7% for 30 years what would be her monthly pay payment.

*asked on March 21, 2013* -
## Math

The flask consist of a cylindrical part and a frustum of a cone. The diameter of the base is 10 cm the diameter is 2 cm while that of neck is 2 cm. The vertical height of the flask is 12 cm. (a) the slant height of the frustum part; (b) the slant height of

*asked on April 4, 2018* -
## Chem; States of Matter

To an insulated container with 100.0 g H2O (l) at 20.0 degrees C, 175 g steam at 100.0 degrees C and 1.65 kg of ice at 0.0 degrees C are added. a) What mass of ice remains unmelted after equilibrium is reached? b) what additional mass of steam should be

*asked on February 11, 2014* -
## math

You receive an invoice for $565.00 with terms 3/10, net 30. If you pay it immediately, how much will you pay? A. $548.05 B. $551.25 C. $558.05 D. $559.95

*asked on June 3, 2011* -
## advanced math

A ladder is placed 4 ft from the side of a building. The top of the ladder must be 13 ft off the ground. What is the shortest ladder that will do the job? 4^2 + 13^2 = x^2 16+169=185^ =34,225

*asked on October 23, 2016* -
## esl

is the statement, 'the blueberries tasted delicious.' a passive statement

*asked on March 8, 2016* -
## math

Tim needs to fill 3 20L barrels with oil. Oil dispenser flows at 100ml/s . How long to fill up 3 barrels. Please help by showing all steps so I can understand how the answer was determined. Thanks!

*asked on October 2, 2015* -
## Physics

A spaceship of mass 2.3×10^6 kg is cruising at a speed of 6.0×10^6 m/s when the antimatter reactor fails, blowing the ship into three pieces. One section, having a mass of 5.2×10^5 kg, is blown straight backward with a speed of 2.0×10^6 m/s. A second

*asked on November 26, 2012* -
## Chemistry

The freezing point of a cyclohexane sample is 6.20*C. A soltuion is prepared by dissolving 0.4660g of an unknown solute in 36.0g cyclohexane. The freezing point of the solution if 4.11*C. Calculate the molar mass of the unknown solute. Kf for cyclohexane

*asked on March 14, 2011* -
## math

The LCD for the fractions 1/3, 3/4, 5/32, and 8/9 is A. 24. B. 64. C. 288. D. 3072. can u show me how to do this

*asked on May 26, 2009* -
## Mathematics

lorinda is given pocket money for a week she decides to spend 2/5 of the money on breakfast, 1/6 of the remaining on snack and 3/4 of what is still remaining on lunch for a day. if she will be left with Gh¢ 100.00 after the first day of making the above

*asked on June 24, 2020* -
## Chemistry - acid base

What volume of 10.0 M NaOH is needed to prepare a buffer with a pH of 7.79 using 31.52 g of TrisHCl? ( Tris. At 25 ∘C, Tris has a pKb of 5.91 ) a) The buffer from Part A is diluted to 1.00 L. To half of it (500. mL), you add 0.0250 mol of hydrogen ions

*asked on March 9, 2018* -
## physics

For the next part, you will need to know that the position d of an object attached to a spring that oscillates with period T=1.0s is a sinusoidal function of time: d=kcos(2πt)d=kcos(2πt) for some constant k. Assume that the initial position of the object

*asked on March 30, 2016* -
## physics

Explain how it is possible for a motorcycle (mass = 250 kg) to have the same momentum as a locomotive engine (mass = 2,500 kg) i though momentum was directly proportional to mass so the more mass the more the momentum? how is it possible then?

*asked on July 1, 2015* -
## physics

The figure below shows a collection of wires. The currents at the numbered points are: I1 = 2.4 mA right; I2 = 3.6 mA down; I3 = 0.60 mA right; I4 = 4.0 mA up; and I5 = 1.6 mA up. i. imgur. com/SCyljHG. png a. What is the current at point A (size and

*asked on March 20, 2013* -
## Chemistry

A 0.0677g sample of magnesium metal reacted with excess hydrochloric acid to produce 69.9 ml of hydrogen gas. The gas was collected over water at 21.0 degrees Celsius. The levels of water inside and outside the gas collecting tube is identical. The water

*asked on February 10, 2011* -
## Trig

An airplane is flying on a compass heading (bearing) of 340 degrees at 325 mph. A wind is blowing with the bearing 320 degrees at 40 mph. Find the component form of the velocity of the airplane. then find the actual ground speed and direction of the plane

*asked on December 17, 2010* -
## english

Which of the following sentences has a helping verb? A. She had rested on the dock. B. He went home late. C. Her brother paddled the canoe. D. She swam across the lake.

*asked on December 10, 2008* -
## CHEM

Many home barbeques are fueled with propane gas C3H8. What mass of carbon dioxide (in kg) is produced upon the complete combustion of 18.9L of propane (approximate contents of one 5-gallon tank)? Assume that the density of the liquid propane in the tank is

*asked on October 14, 2007* -
## Mathss

Item 20 A bathtub is draining at a constant rate. After 2 minutes, it holds 28 gallons of water. Three minutes later, it holds 7 gallons of water. Write an equation that represents the number y of gallons of water in the tub after x minutes.

*asked on December 7, 2017* -
## Physics

Three uniform spheres are located at the corners of an equilateral triangle. Each side of the triangle has a length of 2.50 m. Two of the spheres have a mass of 4.40 kg each. The third sphere (mass unknown) is released from rest. Considering only the

*asked on February 23, 2016* -
## math

During a triathlon, Sharon swims 1/4 of the total route and cycles 3/5 of the remaining route. She runs the rest of the route. If she runs 3,600 meters, find the total distance if the route

*asked on January 14, 2016* -
## Chemistry

How many oxygen atoms are in a) 3.21 x 10^22 molecules CH3OH b) .250 mol C6H12O6 Is it a) 3.21 x 10^22 atoms b) 9.03 x 10^23 atoms

*asked on May 19, 2013* -
## Math

When x^2-5x+3c is divided by x-3 the remainder is -12. What is the value of c?

*asked on February 2, 2011* -
## Math

How many unit cubes would it take to construct the complete exterior of a hollow cube with edges of 4 units and faces 1 unit thick?

*asked on February 2, 2011* -
## math

You purchase a shirt for $8.50. There is a 6% sales tax. Your total cost will be A. $8.55 B. $8.98 C. $9.01 D. $13.60 how can i solve this?

*asked on May 28, 2009* -
## math

A researcher uses analysis of variance to test for mean differences among three treatments with a sample of n = 12 in each treatment. The F-ratio for this analysis would have what df values?

*asked on November 22, 2015* -
## chemistry

A solution is 40% acetic acid by mass. The density of this solution is 1.049 g/mL. Calculate the mass of pure acetic acid in 170 mL of this solution at 20 C. Answer in units of g The density of a solution of sulfuric acid is 1.29 g/cm3 and it is 38.1% acid

*asked on September 2, 2013* -
## Chemistry

Sodium azide (NaN3) yields N2 gas when heated to 300 degrees Celsius , a reaction used in automobile airbags. If 1.00 mol of N2 has a volume of 47.0 liters under the reaction conditions , how many liters of gas can be formed by heating 35g of NaN3? The

*asked on March 3, 2013* -
## economincs

The price elasticity of demand for imported whiskey is estimated to be −0.20 over a wide interval of prices. The federal government decides to raise the import tariff on foreign whiskey, causing its price to rise by 20 percent. a. Will the quantity

*asked on February 27, 2013* -
## Chemistry

How many milliliters of 3.0 M NaOH are required to react with 4.0mL of 16.0 M HNO3? ---> Not sure if I am solving correctly but I keep getting 21mL.

*asked on March 6, 2011* -
## Math

How many five-digit integers are perfect squares?

*asked on January 9, 2011* -
## ALGEBRAIC FRACTIONS

find the illegal values of C in the multiplication statement c^2-3c-10/c^2+5c-14 . c^2-c-2/c^2-2c-15

*asked on December 12, 2010* -
## earth science

oceanography is one of the oldest sciences. false right

*asked on August 16, 2008* -
## stats

The probability is 0.35 that a traffic fatality involves an intoxicated or alcohol-impaired driver or nonoccupant. In ten traffic fatalities, find the probability that the number, Y, which involve an intoxicated or alcohol-impaired driver or nonoccupant is

*asked on March 16, 2020* -
## Math

4x=36

*asked on September 29, 2018* -
## math

The vertices of ABC are A(2,-5), B(-3,5), and C(3,-3).the triangle is reflected over the x-axis.use arrow notations to describe the original triangle and its reelection. A) A(2,-5),B(-3,5),C(3,-3)->(2,-5),(-3,5),(3,-3) B)

*asked on May 17, 2014* -
## statistics

Data were collected on 100 students regarding their class and major. The data are summarized in the following contingency table. What is the probability of randomly selecting a sophomore or an undeclared student?

*asked on April 23, 2014* -
## Chemistry

For example, when a question asks about two equivalents of bromine, does that mean Br2 OR 2Br2? Thanks

*asked on January 20, 2014* -
## Chemistry (Dr.Bob222)

The half-life of P-32 is 14 days. How long after a sample is delivered can a laboratory wait to use a sample in an experiment if they need at least 10 percent of the original radioactivity? I need help on how to set up this problem. What is the general

*asked on November 7, 2013* -
## Physics

A car travels in a straight line with an average velocity of 80 km/hr for 2.5 hours and then with an average velocity of 40 km/hr for 1.5 hours. a. Calculate the largest displacement for the 4-hour trip. b. Calculate the largest average velocity for the

*asked on August 28, 2013* -
## PHYSICS!!!

Water moves through a constricted pipe in steady, ideal flow. At the lower point shown in the figure below, the pressure is 1.70 105 Pa and the pipe radius is 2.80 cm. At the higher point located at y = 2.50 m, the pressure is 1.22 105 Pa and the pipe

*asked on November 11, 2012* -
## physics

In a large hotel, a fast elevator takes you from the ground floor to the 21st floor. The elevator takes 17 s for this trip: 5 s at constant acceleration, 7 s at constant velocity, and 5 s at constant deceleration. Each floor in the hotel has a height of

*asked on September 26, 2011* -
## statistics

Heights of fences are normally distributed with a mean of 52 inches and a standard deviation of 4 inches. Find the probability that one randomly selected fence is under 54 inches.

*asked on July 5, 2011* -
## physics

Two electrostatic point charges of +30 ìC and +25 ìC exert a repulsive force of 200 N on each other. What is the distance between the two charges?

*asked on March 25, 2011* -
## Chemistry

A 0.188g sample of unknown metal, X (s), produced 71.4 ml of hydrogen gas when reacted with HCL according to the equation: X(s)+2HCL(aq)--->XCl2(aq)+H2(g) The gas was collected over water at 23 degrees Celsius. The levels of water inside and outside the

*asked on February 10, 2011* -
## Chemistry

Concentrated sulfuric acid is 18.4 molar and has a density of 1.84 grams per milliliter. After dilution with water to 5.20 molar the solution has a density of 1.38 grams per milliliter. This concentration of H2SO4 is often used in lead storage

*asked on January 13, 2011* -
## chemistry

What is the final temperature of a 52 gram glass of water at 2.0 C if it absorbs 3.0 J heat?

*asked on October 12, 2010* -
## vocabulary

After the play _____, several critics made scathing comments about it. a)succeeded b)opened c)closed d)bombed a is that correct

*asked on January 31, 2010* -
## physics

Two rock climbers, Bill and Karen, use safety ropes of similar length. Karen's rope is more elastic, called a dynamic rope by climbers. Bill has a static rope, not recommended for safety purposes in pro climbing. Karen falls freely about 1.7 m and then the

*asked on December 12, 2009* -
## CHEM - PLS help!!

What would the equation look like if you added bromine (Br) in the presence of CH2Cl2 (Dichloromethane) to cyclohexanol (C_6H_11 OH). Would the solution become saturated or not??? What would the colour change be...if any?? Would a precipitate be formed??

*asked on February 25, 2008* -
## O-CHEM (PLEASE CHECK)

How many stereoisomers are there for 1,2-dichlorocyclopentane?: a) 1 b) 2 c) 3 d) 4 answer: "B" (2)??? or: "D" (4)??? How many stereoisomers are possible for: cortisone acetate?: a) 32 b) 64 c) 128 d) 256 answer: "B" (64)??? How many stereoisomers are

*asked on February 24, 2008* -
## physics

when polonium-210 undergoes alpha decay, lead-206 is produced. What is the same and different between the two elements?

*asked on March 4, 2020* -
## PHYSICS

A man who weighs 600 N is sitting in a chair with his feet on the floor and arms resting on the armrests. The chair weighs 100 N. Each armrest exerts an upward force of 25.0 N on his arms, and the seat exerts an upward force of 500 N. What force does the

*asked on September 19, 2019* -
## PHYSICS

A box is pushed across a horizontal table by a boy applying a force of 32 N to the box. A force of friction of magnitude 19 N acts opposite the direction of motion. A stiff wind also opposes the box’s motion. What magnitude of force does the box exert on

*asked on September 19, 2019* -
## Physics

A Ferris wheel with radius 9.5 m initially rotates at a constant rate by completing 0.75 rev in 25.00 s. It then begins to decelerate at a rate of 0.30 rad/s2 with its only passenger at the top of the wheel. Find the direction of the total acceleration

*asked on July 19, 2018* -
## Math

Pupils in a school prepared a circular flower garden of diameter 28 meters. They dug holes each 4 meters apart along the circumference for planting flowers. How many holes were dug?

*asked on February 2, 2018* -
## Math

In a cupboard there are pencils, rulers and books. The number of pencils is 15 more than that of rulers. The number of books is three time that of rulers. If the number of pencils is p, which one the total number of items in the cupboard?

*asked on January 15, 2018* -
## physics

a 15kg rock falls from the top of a building 8.0 high. Find its PE and KE a.when at rest at the top of the building b. halfway down the ground c. when it reaches the ground d.speed when it reaches the ground

*asked on September 26, 2016* -
## algebra

. On the reality TV show Last Man Standing, a package is thrown from a plane to the ocean below. The contestants must swim to the package to receive the “free pass” located inside the package. The path that the package follows can be modelled by the

*asked on July 11, 2016* -
## science computer

Write a program to read the names and age of 10 people and print the name of the oldest person.assume that there are no person of the same age.data is supplied in the following form:name,age,name,age

*asked on March 13, 2016* -
## physics

A long straight horizontal wire carries a current I = 4.80 A to the left. A positive 1.00 C charge moves to the right at a distance 5.00 m above the wire at constant speed v = 4500 m/s . What is the magnitude B of the magnetic field at the location of the

*asked on March 3, 2016* -
## physics

A ball (mass 12 kg) moving at 15 m/s in the +x-direction collides with a ball (mass 36 kg) moving at 5.0 m/s in the +y direction. After colliding, the 12-kg ball moves at 6.0 m/s at an angle of 30°above the +x direction. Afterward, what is the speed and

*asked on July 1, 2015* -
## chemistry

calculate the grams of 1.8% (m/m) NaCl solution that contains 8.00 g of NaCl I tried 1.8 times 8.00g divided by 58.44g times 100 my answer is 24.6g rounded to 2 SF is 25g this truned out to be wrong I'm stumped!

*asked on April 1, 2015* -
## math

After 5 years, marcels account earned $ 600 in interest. If the interest rate is 0.03, how much did marcel initially invest?

*asked on February 19, 2015* -
## chemistry

A sample of co2 occupies 6.00l at 25c and 700. MmHg. What is the volume of the gas at stp

*asked on December 21, 2014* -
## chemistry

Draw one of the Lewis structure of the N2O5. In each case one oxygen bridges the nitrogens (N-O-N single bond) and 2 other oxygens are bonded to each N. How many equivalent resonance structures are there that satisfy the octet rule and where O makes at

*asked on November 6, 2014* -
## 4th grade math

128,955 . Round each number to the place of the underllined digit. 8 is the underlined digit

*asked on September 8, 2014* -
## Chemistry (Dr. Bob222)

How can you tell if something is highly concentrated or lowly concentrated? For example: H2CO3, H+, HCO3-, CO3(2- charge), is in order of highest concentration to lowest concentration, can you explain why it is that order? Thanks for your help :)

*asked on November 2, 2013* -
## Chemistry help (DrBob222)

propane (c3h8) is burned in oxygen to produce carbon dioxide and water. The heat of combustion of propane is -2012 kJ/mole. How much heat is given off when 3.0 mol C3H8 are react with 10.0 mol O2? Thanks, and please if possible show all steps!

*asked on October 15, 2013* -
## Physics

A 1.0 x 10^3 kg elevator carries a maximum load of 800.0 kg. A constant frictional force of 4.0 x 10^3 N retards the elevator's motion upward. What minimum power, in kilowatts, must the motor deliver to lift the fully loaded elevator at a constant speed of

*asked on July 7, 2013* -
## physics

Object I is a solid cylinder with diameter d has resistance R. What would be resistance of another object made of the same material and with the same mass as Object I but has the cross section shown below (it is a hollow cylinder with outer diameter 2d and

*asked on March 21, 2013* -
## calculus

three bowls are filled to a depth of four units. a paraboloid, z=x^2 +y^2 for 0

*asked on January 29, 2013* -
## Statistics

foofy computes the correlation between an individual's physical strength and his or her college grade poing average. Using a computer, the correlation for a sample of 2000 people is r(1998)=+.08, p=

*asked on July 10, 2011*