# Richard

Popular questions and responses by Richard-
## More Organic Chem.

1. Would you expect ibuprofen to be soluble or insoluble in 1.0 M NaOH? Explain. 2. Thymol is very slightly soluble in water and very soluble in 1.0 M NaOH. Explain. Any info. would help! Below are two web pages. The first shows ibuprofen has a -COOH group

*asked on February 5, 2007* -
## chem class

A 25.00-mL sample of 0.723 M HClO4 is titrated with a 0.273 M KOH solution. The H3O+ concentration after the addition of 10.0 mL of KOH is ???? M.

*asked on November 23, 2010* -
## chemistry

Calculate the number of moles of FeSO4 in 25cm3 of a 0.2mol dm3 solution

*asked on June 21, 2011* -
## Chem.

If 0.130 g of p-aminophenol is allowed to react with excess acetic anhydride , what is the theoretical yield of acetaminophen in moles? In grams? p-amino. - MW: 109.13g aceta. - MW: 151.16 g ** I just forgot how to do this, I know it's probably REALLY

*asked on February 27, 2007* -
## Physics

What is the value of each of the angles of a triangle whose sides are 95, 150, 190 cm in length? I have tried to do this problem, don't get me wrong, but I don't really know where to go. Can someone tell me how to even approach this problem? The textbook

*asked on July 6, 2014* -
## Chemistry

Can anyone help me check my classifications of these into metallic, ionic, molecular or covalent network, and if I am wrong tell me why Aluminum - Mettalic Ascorbic acid - ionic Graphite - covalent Paraffin - molecular Palmitic acid - ionic Sodium chloride

*asked on February 20, 2018* -
## College Algebra

The sum of three consecutive natural numbers is 966. Find the numbers.

*asked on July 23, 2015* -
## Physics

a uniform metre rule pivoted at R, the 70cm mark. Two forces 0.1 N and 0.4 N are applied at Q, the 60cm mark and S, the 85cm mark. If the metre rule us kept in equilibrium, by the forces, calculate the weight of the metre rule.

*asked on November 4, 2018* -
## Physics

A uniform metre rule AB us balanced on a knife edge which is 55cm from B. If a mass of 10g is hung at P, which is 10cm from A, calculate the mass of the metre rule. Please HELLLLP URGENTLY!!!!!!😥😥😥😥😥😥😫😫😫😫😫

*asked on October 23, 2018* -
## Chemistry check my answer?

Hi! is my answer correct? Consider the following chemical reaction: H2 (g) + I2 (g) 2HI (g) At equilibrium in a particular experiment, the concentrations of H2, I2, and HI were 0.15 M, 0.033 M, and 0.55 M, respectively. The value ofKeq for this reaction is

*asked on October 25, 2010* -
## Math

Write 116 2/3 as a fraction or mixed number.

*asked on August 16, 2009* -
## chemistry.

Lithium hydroxide reacts with carbon dioxide as follow. 2LiOH + CO2________ Li2CO3 + H2O What mass (in grams) of Lithium hydroxide is need to react with 11 g of carbon dioxide?

*asked on September 28, 2009* -
## Science

Which of the following would be the best explanation for the existence of the Andes Mountains along the west coast of South America? (1) the collision of two tectonic plates (2) the gravitational pull of the sun, the moon, and the planets 3) the magnetic

*asked on September 26, 2020* -
## college physical science

According to table 1.3, what volume of iron would be needed to balance a 1.00cm3 sample of lead on a two pan laboratory balance? Table 1.3 shows densities g/cm3 such as iron=7.87g/cm3 and lead is 11.4g/cm3

*asked on August 29, 2010* -
## Physics

A 0.150 kg particle moves along an x axis according to x(t) = -13.00 + 2.00t + 3.50t2 - 2.50t3, with x in meters and t in seconds. In unit-vector notation, what is the net force acting on the particle at t = 3.45 s? I tried solving using s=Vit + (.5)at^2

*asked on September 22, 2009* -
## science

if a substance is known to enter a cell by diffusion, what effect would raising the temperature have on the cell? Why does it have this effect?

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

a ball projected vertically upwards from the top of the tower 60 meters high with a velocity of 30 meters per second. what is the maximum height above the ground? how long does it take to reach the ground?

*asked on August 28, 2016* -
## chemistry

1.Use the Vsepr theory to predict and explain the shape and bond angle of each of the molecules SCI2 and C2CL2. 2.Deduce whether or not each molecule is polar, giving a reason for your answer...Any help please??

*asked on February 28, 2010* -
## business

Direct verse indirect cost Estep Construction Company is composed of two divisions: (1) Home Construction and (2) Commercial Construction .The Home Construction Division is in the process of building 12 houses and the Commercial Division is working on 3

*asked on March 26, 2011* -
## 9th grade

A square made by a length of string 8 cm long is reshaped into a circle. What is the circumference of the circle

*asked on September 24, 2010* -
## Biology

The density of ice is 916.7 kilograms per cubic meter at 0 degrees Celsius under atmospheric pressure. Columbia Glacier, in Alaska, loses about 4 billion metric tons of ice each year. About what volume of water melts from the glacier each year? Im confused

*asked on September 28, 2019* -
## Physics

a mercury in glass thermometer reads -20°C at the ice point and 100°C at the steam point. Calculate celcius temperature corresponding to 70°C on the thermometer

*asked on June 6, 2019* -
## chemistry correction

1. Which two elements react vigorously with each other? A: Chlorine and lithium B:Chlorine and potassium C:iodine and lithium D:iodine and potassium my answer is B 2. which statement about electronegativty is correct. A: Electronegativity decrease across a

*asked on March 11, 2010* -
## Math

First Estimate the answer. Then find the exact answer. Simplify your answer if possible. 9*2/7*8/5/7

*asked on September 13, 2009* -
## hardware

what is hardware

*asked on June 8, 2008* -
## Organic Chem.

When a tlc plate was developed the solvent front ran off the top of the plate, why? A two component mixture containing a dicarboxylic acid and tricarboxylic acid gave only one spot with an Rf value of 0.05. Solvent used; hexane. What went wrong? Solvent

*asked on February 5, 2007* -
## science(physics)

A piece of copper block of mass 24g at 230 degree celsius is placed in a copper calorimeter of mass 60g containing 54g of water at 31 degree celsius.Assuming heat losses are negligible,calculate the final steady temperature of the mixture (Specific heat

*asked on July 7, 2019* -
## Math

A child's desk is made so that the dimensions are two-thirds the dimensions of a full-size adult desk. Suppose the top of the full-size desk measures 54 inches long by 36 inches wide. What is the perimeter and area of the topof the child's desk?

*asked on September 24, 2015* -
## geometry

What happened when two fruit companies merged?

*asked on November 16, 2011* -
## Lab conclusion- HELP!

I' am currently trying to wrie a couple of lab conclusions and having a hard time coming up with good points to make for the following lab experiment: Thin layer chorotography If anyone has a few minutes to give me a couple tips on how to improve this. I

*asked on February 5, 2007* -
## Mathematics

Select 5 numbers from 1to 90numbers,and we have win and machine side.if a numbers is plays .win 78-9-64-86-13&mach61-2-21-72-70and the following week plays win 54-66-13-42-15&mach12-32-22-8-61. What will be next win & machine numbers for the next week.

*asked on September 29, 2020* -
## Maths

a map with a scale of 1cm to 5km has an area of 405cmsquare. what is the actual area of this map on the ground?

*asked on April 28, 2016* -
## CHEMISTRY

How to prepare a 500ml 0.2M NaOH solution from 2.0M NaOH solution

*asked on July 10, 2013* -
## English

Reading the book Twilight by Stephenie Meyer. Will have to write book report in class 11/13/07. Has anyone read the book and written a book report on it.

*asked on November 8, 2007* -
## math

A number is written with the following factorization:2² x 3 x 5⁴ x 8 x 11².Is this factorization a prime factorization? Explain why or why not. If it is not correct, give the correct prime factorization of the number.

*asked on December 6, 2018* -
## algebra

A 12 - ft ladder leans against the side of a house. The bottom of the ladder is 6 ft from the side of the house. How high is the top of the ladder from the ground? If necessary, round your answer to the nearest tenth.

*asked on August 10, 2017* -
## Physics (Thin Film Interference)

A layer of transparent plastic (n=1.61) on glass (n=1.52) looks dark when viewed in reflected light whose wavelength is 589 nanometers in vacuum. Find the two smallest possible nonzero values for the thickness of the layer. Answers are 183 nm and 366 but I

*asked on October 11, 2015* -
## precalculus

use pascal's triangle to expand the expression (2x-3y)^3

*asked on May 9, 2015* -
## Physics

A bead slides without friction around a loop- the-loop. The bead is released from a height of 12.9 m from the bottom of the loop-the- loop which has a radius 4 m. The acceleration of gravity is 9.8 m/s2 . A 4m 12.9 m What is its speed at point A ? Answer

*asked on December 14, 2012* -
## math

solve by the elimination method: 9x-9y=18 7y-3x=-8 please solve step by step thank you for your help

*asked on July 25, 2011* -
## chem

What is the [OH-] for a solution at 25°C that has [H3O+] = 8.23 × 10-2 M?

*asked on March 5, 2011* -
## trig

Graph three periods of the function. (identify period and phase shift and intercepts) y = f(x) = √3/2 sin(2x) - 1/2 cos(2x) if you can't graph it can you at least get it into that simpler form which is graph able.

*asked on May 5, 2010* -
## chemistry

Magnesium reacts with HCl(aq) to form MgCl2 and H2(g) ____ Mg(s) + ____ HCl(aq) -----> ____ MgCl2(aq) + ____ H2(g) The following data was collected for the above reaction: Mg (g) 5% (m/v) HCl (ml) H2 gas produced (ml) 0.50 10 167 0.50 20 333 0.50 30 500

*asked on January 29, 2010* -
## math

Is The factors of 385 = 1,5,7,55,77,385?

*asked on September 5, 2009* -
## org. chem

why is it easier to remove excess acetic acid from the products than excess isopentyl alcohol? from the products of what? Did you perform an experiment in class and this is one of the lab questions? If so you will need to explain what you did in some

*asked on March 7, 2007* -
## Physics

(PLEASE HELP ME URGENTLY) The electrical resistances of the element in a platinum resistance thermometer at 100°C, 0°C and room temperature are 75.000W, 63.000W and 64.992W respectively. Use these data to determine the room temperature. (PLEASE HELP ME

*asked on June 7, 2019* -
## Marketing

Explanation of leadership without followership is nonesense and impossible in relation to the principles of marketing management..... PLLLLEAAASE ASSIST ME!!!!

*asked on October 24, 2018* -
## Physics

A uniform metre rule of mass 90g is pivoted at the 40cm mark. If the rule is in equilibrum with an unknown mass, M placed at the 10cm mark and 72g mass at the 70cm mark, determine M. Please help me urgently!!

*asked on October 23, 2018* -
## Chemistry

Ammonia (NH3) reacts with oxygen to produce nitric oxide (NO) and water (see balanced equation below). How many grams of oxygen do you need to react with 21.4 g ammonia? __4_NH3 + __5_O2 → __4_NO + _6__H2O

*asked on October 2, 2016* -
## Algebra

Explain how you can tell the function is not linear by using points on its graph. Make sure to include in your answer the Points you used to determine that the function is not linear.

*asked on April 28, 2016* -
## Chemistry

Part 1 of 2 Write the balanced molecular equation for the reaction between iron metal (the nail) and aqueous copper II sulfate and classify this reaction. Include the states: solid (s), liquid (l), aqueous (aq), or gas (g). Use your observations to help

*asked on January 11, 2015* -
## Science

Hannah is comparing a rock from a riverbed and a rock from deep underground. One is very smooth, and the other has very rough edges. Explain why each rock was probably found in that location.

*asked on January 9, 2014* -
## Macroeconomics

Graph the following aggregate supply and demand curves (be sure to draw to scale). Real GDP (in $ trillions) Price Level Supplied Demanded Increase / Decrease 100 4 16 110 10 15 140 14 12 200 15 6

*asked on April 15, 2013* -
## chemestry

How many grams of O2 are needed to produce 45.8 grams of Fe2O3 in the following reaction? 4Fe(s)+3O2(g) - 2Fe2O3(s)

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

Differenciate between speed and velocity

*asked on January 22, 2013* -
## Government

If you asked the same question about an upcoming election to many people,you would be conducting a? A.Scientific poll B.Straw Vote C.Public Agenda D.Representative Sample

*asked on May 10, 2012* -
## Maths

14 metres of rope costs €9.52. If Joe bought 21 metres, how much change out of €20.00 do Joe get? Is there a shorter way of doing this other than dividing, multiplying and then subtracting?

*asked on March 22, 2012* -
## Math-Statistics

Find a confidence interval for ƒÊ assuming that each sample is from a normal population. a. P x = 14, ƒÐ = 4, n = 5, 90 percent confidence b. P x = 37, ƒÐ = 5, n = 15, 99 percent confidence c. P x = 121, ƒÐ = 15, n = 25, 95 percent confidence

*asked on December 6, 2011* -
## Physics

What minimum strength of magnetic field is required to balance the gravitational force on a proton moving at speed 6*10^6 m/s?

*asked on December 4, 2011* -
## Physics

What is the fundamental frequency for a 62 cm banjo string if the speed of waves on the string is 470 m/s?

*asked on November 7, 2011* -
## Physics

How long is a wavelength of infrasound with a frequency of 4 Hz?

*asked on November 7, 2011* -
## Physics

Radio waves travel at the speed of light, which is 3.00 108 m/s. What is the wavelength for a FM station broadcasting at 105.9 MHz (the prefix M is "mega" and means 106)?

*asked on November 7, 2011* -
## math

a 4 digit number my 2 nd digitis twice my 3 digit the sum of all my digits is 3 times greater than my last digit the productof my 3rd and 4th digits is 12 times greater than the ratio of my 2nd to 3rd whats my number?

*asked on August 18, 2011* -
## college chem

The cation M2+ reacts with NH3 to form a series of complex ions as follows: M2+ + NH3 M(NH3)2+ K1 = 102 M(NH3)2+ + NH3 M(NH3)2 2+ K2 = 103 M(NH3)2 2+ + NH3 M(NH3)3 2+ K3 = 102 A 1.0 × 10–3 mol sample of M(NO3)2 is added to 1.0 L of 15.0 M NH3 (Kb = 1.8

*asked on April 24, 2011* -
## chem101

propyl Bromide reacts with Mg, Propanone, H+ to yeild what?

*asked on March 26, 2011* -
## chem101

Hydrogen gas can be produced in the lab by the reaction of magnesium metal and hydrochloric acid. Mg + 2 HC -> MgCl2 + H2 How many grams of hydrogen gas will be produce if 5.00 g of magnesium metal is dissolved in excess acid.

*asked on March 24, 2011* -
## 3rd grade

What is a number sentence that shows the same product as the product of 9 and 2

*asked on December 9, 2010* -
## english

How might readers react if the topic sentences in an essay did not coincide with the supporting points, and why would their reaction be justified?

*asked on March 28, 2011* -
## Chemistry

A buffer prepared by mixing equal amounts of the salts Na2HPo4 and NaH2PO4 to give a total phosphate concentration of 0.1M. What is the concentration of Na ions? I believe it is 0.3M but am having trouble understanding why when I write out the dissociation

*asked on June 30, 2010* -
## Physics

Having trouble determ the formulas for the follow problems. 2. If an automobile travels at 30 km/hr. for 2 hours, how far does it go? 60 km 3. At time = 0 an automobile already traveling at 30 km/hr. accelerates at 3m/s2 for 2 seconds. During these two

*asked on May 29, 2010* -
## Physics hard...

Young's Modulus (Y) 20 X 1010 N/m2 Shear Modulus (S) 8.1 X 1010 N/m2 Bulk Modulus (B) 16 X 1010 N/m2 The table to the above represents various properties of steel. You have steel wire 4.9 meters in length that stretches 0.16 cm when subjected to a force of

*asked on May 6, 2010* -
## Trigonometry

Find all solutions for the following equation in the interval 0 ≤ x

*asked on May 4, 2010* -
## social studies

Why did Mao Zeodong led the cummunists to power in china

*asked on April 22, 2010* -
## Math

The exhibit hall at the fair is dividid into three sections. Tow-fifths of the exhibits are in section B of the hall, and another two-fifths ain in section C. What fraction of the exhibits are in located in section A? We have multiple choice answers. Thank

*asked on March 1, 2010* -
## chemistry

1.predict and expalain the order of melting point for propanol, butane, and proanone with refernce to their intermolecular forces. 2. The element sodium, aluminum, silicon, phosphrous, and sulfur are in periods 3 of the periodic table. Decribes the

*asked on February 26, 2010* -
## history

What were the main elements of Johnson’s War on Poverty?

*asked on December 14, 2009* -
## Calculus

Would someone please tell me how to solve these two problems? Find the indefinite integral: x(x-1)^5 dx (v^2)(1-v)^6 dv

*asked on November 18, 2009* -
## 6th grade math

28 x 15 simplify by using distributive property,

*asked on September 10, 2008* -
## math

write 3x^2 +8x-25 in the form a(x+h)^2,where a,h and k are real numbers

*asked on April 9, 2008* -
## mathFormula

Formula for calculating cubic feet. length(in feet) x width(in feet) x height(in feet) = volume in cubic feet. Thank you DrBob That's for a cube or four sided regular figures. For a cylinder, it's pi*(radius2)*height and there are other formulas for other

*asked on August 20, 2007* -
## Mathematics

An arc of length 28cm subtend an angle of 24° at the center of the circle. In the same circle what does an arc of 35cm subtend

*asked on July 23, 2020* -
## chemistry

explain why helium is used instead of hydrogen in balloons for meteorological research

*asked on November 21, 2019* -
## Science

A toy rocket of 5.0 kg is launched from rest and reaches a height of 100 M in two seconds. What is the work done by the engine during this non acceleration stage?

*asked on April 28, 2019* -
## Statistics

A politician is preparing to speak to voters in Connecticut. He DOES NOT favor gun control laws. However, a survey of 1200 voters from this state resulted in 984 voters that supported some level of gun control laws. (Assume a good random sample was taken).

*asked on April 22, 2019* -
## math

if you made a stack of nickels 100 inches tall,how many nickels would you need

*asked on January 18, 2019* -
## Physics

If light travels through a medium at a speed of 1.987 x 10^8 m/s, what is the index of refraction of the medium? * 1.33 1.36 1.51 1.53

*asked on April 8, 2018* -
## Math - Algebra

An architect is designing a building in the shape of a rectangular pyramid. The number of windows on each floor forms an arithmetic sequence. There are 76 windows on the 7th floor, 68 on the 8th floor, and 4 on the very last floor Find an explicit formula

*asked on February 19, 2018* -
## 5th grade math equation

I have tried everything to help my son and I can't figure it out. I am trying to get an end result of 38 out of the following equation. We have to add parentheses to make it equal 38 any help !!! 3+6*5+4/2-7

*asked on March 26, 2017* -
## Chemistry

Thanks to Dr. Bob for answering all these questions! I always do poorly on conceptual problems. Consider the following equilibrium system at 25°C and select the true statement below: H2PO4−(aq) + SO42−(aq) ↔ HSO4−(aq) + HPO42−(aq) ΔG°rxn > 0

*asked on February 27, 2017* -
## calculus

How would you use series to evaluate the lim(x->0) of (x-arctanx)/x^3? I'm getting stuck, and the answer says it's 1/3 but I don't know how they got there.

*asked on February 26, 2017* -
## calculus

How would you determine the power series of 1/(1-x)^3. I know that the series of 1/(1-x) is x^n, but how would you manipulate it for this scenario?

*asked on February 26, 2017* -
## math

there are 20 students in mark`s homeroom class. Ten percent of the students in marks homeroom class are also in art class He finds the number of students in his homeroom class who are also in art class like this . Can you tell me the answer of how many

*asked on February 16, 2017* -
## math-integrating factor

dy/dx - y/x = 0 I got 1/x, but I am not sure if this is right or not.

*asked on December 25, 2016* -
## Algebra 2

There are 41 individuals in a grocery store, of which 18 are female. the total number of individuals who are 30 years old or older is 24 of which 10 are female. If an individual is randomly selected, what is the probability that they are either male or 30

*asked on November 17, 2016* -
## chemistry

pH of 1.0 x 10-8 M RbOH

*asked on July 24, 2016* -
## math

A flame is ejected vertically upward from the groung at 15m/s.Find the height of the flame after 2.5seconds

*asked on June 29, 2016* -
## life orientation

Clealy describe a recent corruption and fraud cases in the country making headlines in the media

*asked on April 29, 2016* -
## Physics

A Ball Of Mass 0.25kg Losses Half Of Its Velocity When It Makes A Head On Collision With An Identical Ball Q At Rest.After The Collision,Q Moves off with a speed of 2m/s in the original direction of p.calculate the initial velocity of p.

*asked on April 17, 2016* -
## Intro to Chemistry

A 9.40-L container holds a mixture of two gases at 47 °C. The partial pressures of gas A and gas B, respectively, are 0.344 atm and 0.520 atm. If 0.160 mol of a third gas is added with no change in volume or temperature, what will the total pressure

*asked on March 9, 2016* -
## MATH PLEASE

1. ZG Jewelers purchased fashion bracelets for $38.87. This jewelry store regularly marks up fashion merchandise 52% of the selling price. What is the minimum selling price that ZG Jewelers should charge? 57.20 59.23 80.98 94.94

*asked on February 25, 2016*