# Posts by David

Total # Posts: 2,272

**chemistry**

If a hydrate of the formula decomposes when heated to produce HCl, what change would you expect to occur when a piece of blue litmus paper is held in the path of the vapor released? [Litmus paper is paper impregnated with an acid-base indicator that is blue in the presence of ...

**chemistry**

sorry would i multiply the moles of O2 by the 1(0.208) to get the concentration which is proportional to the molarity?

**chemistry**

Okay, so this is how I think I should set it up? can you confirm it at least. Anyways I would try to find moles of O2 using ideal gas law (1.00 atm)(0.283)/(0.0821)(298) = n moles O2. then I would multiply 0.208 by the 1 L of water?? Then divide the moles of O2 / by L of water...

**chemistry**

Under an O2 pressure of 1.00 atm, 28.31 mL of O2 dissolves in 1.00 L H2O at 25 degrees. Determine the molarity of O2 in an aqueous solution at equilibrium with air at normal atmospheric pressure. The volume percent of O2 in air is 20.80 \%. (Have no idea how to go through with...

**chemistry**

oh. that's the complete opposite of what i thought. thanks

**chemistry**

An ideal liquid solution has two volatile components. In the vapor in equilibrium with the solution, the mole fractions of the components are (a) both 0.50; (b) equal, but not necessarily 0.50; (c) not very likely to be equal; (d) 1.00 for the solvent and 0.00 for the solute. ...

**chemistry**

Under an O2 pressure of 1.00 atm, 28.31 mL of O2 dissolves in 1.00 L H2O at 25 degrees. Determine the molarity of O2 in an aqueous solution at equilibrium with air at normal atmospheric pressure. The volume percent of O2 in air is 20.80 \%. (Have no idea how to go through with...

**chemistry**

nope. have to contact my teacher about this.

**chemistry**

How many grams of water would you add to 1.00 kg of 1.48 m CH3OH(aq) to reduce the molality to 1.00 m CH3OH? Ok...I got 480, and the systems says there's a rounding error. I did it again and I got 480. Someone help me?

**biology 102**

I've already done it, thank you. Was wondering if there were any other predictions.

**biology 102**

A prediction (educated guesses as to what the potential results may be) for each experiment listed below: 1) knee-jerk reflex 2) pupillary reflex (shield left eye, shine bright light into right eye, observe pupils) 3) 2-point threshold 4) temperature discrimination 5) ...

**business**

describe two forces that you believe shape the relationship between business and society. Provide two examples (one for each force you choose). Look for flaws and strengths in specific examples and applications

**MATH**

a<9. Not sure about the graph 3a<19+8 3a<27 a<27/3 a<9

**Math**

That's what I got.

**Chemistry**

Explain how to make a 1 Normal solution H3PO4.

**Chemistry**

What is the normality of 10 ml of an acid that took 25 ml of 0.25 N NaOH to reach pH 7?

**Chemistry**

You were using H3PO4 to make an acid solution. What is the equivalent weight of H3PO4

**Chemistry**

if you have 100 mg of CaCl2, how many moles of Cl do you have

**CHEMISTRY**

what is 0.00225 in two sigs? i hate sig figs -.-. thank you though.

**CHEMISTRY**

I calculated using the proportion and got 0.00025, and it was wrong. Then I used 9 ppb times 1000000 ml/ 1 ppb = 9000000, and used the proportion setup and still got it wrong.

**CHEMISTRY**

1.) A water sample is found to have 9.0 ppb of chloroform,CHCL3. How many grams of CHCL3 would be found in a glassful (250 ML) of this water?

**chemistry**

The second one is correct. Regarding the first one though, I calculated the grams to 6.8 g of C2H5OH. I don't quite understand the next step (regarding the density, etc)

**College Math : Linear Algebra**

Well I guess no one can help. :/ Oh well, I'll figure it out

**College Math : Linear Algebra**

Suppose A is a square matrix satisfying the equation A^3 - 2I = 0. Prove that A and (A - I) respectively are invertible. (the hint is to find an explicit equation for A^-1. To prove A is invertible, this is what I did although I don't that it's right: A^3 - 2I = 0 A(A^...

**long-term**

What other challenges do case workers face when working with placement of the elderly in long-term care facilities?

**calculus**

How large does N have to be in order to approximate the integral of cos(x^2) from 0 to 1, using the Midpoint Rule, with error at most 10^(-6)?

**algebra**

Find an equation of the porabola described. - Vertex(0,0);directrix x + 1 = 0

**programming**

I am working on a project called VB Auto Sales I am working in CH 2. I have just about completed the assignment but I am unable to group two separate sections. Assignment Modify the project from the Chapter 1 VB Auto Center case study, replacing the buttons with images in ...

**Visual Basic**

I should say I cannot get the special notices to work with the colors.

**Visual Basic**

I am working on a project called VB Auto Sales I am working in CH 2. I have just about completed the assignment but I am unable to group two separate sections. Assignment Modify the project from the Chapter 1 VB Auto Center case study, replacing the buttons with images in ...

**Chemistry (Grade 11)**

A radioactive sample of 141Cs has a half-life of 32.5 days. In a sample that contains 8.00*10^7 nuclei of 141Cs, how many beta particles per second will be emitted? A 19.8 B 1.7*10^6 C 71 076 D 1185 E 2.47*10^-7 The 141 supposed to be a superscript text, but firefox won't ...

**6th Grade Science : Newtons First Law of Motion**

Explain the idea of streamlining, as it applies to a skydiver.

**6th Grade Science : Newton's First Law of Motion**

Explain the idea of streamlining.\, as it applies to the skydiver. If you have the following textbook: Scott Foresman Science, 6th Grade good for you! Look on pages B102 - B105.

**6th Grade math**

Use prime factorization.

**6th Grade math**

The Odgen School marching band has 91 musicians. If there are 7 student musicians in each row, how many rows are there?

**Maths**

That would make more sense! Many thanks

**Maths**

Please could I have some guidance and advice on the following question? A multiple choice question has 4 options, A,B,C and D. The numbers of students choosing the options are in the ratio 3:1:2:14. I need to calculate the number of students choosing each option, (there are ...

**shapes**

if i had just a regular triangle and then it turned 90 degrees how would it look

**11th grade math**

secondary largest possible answre is Answer: x⋅(38-2⋅x)2 Answer: 8.06181572077

**11th grade math**

had this same probem for college pre-calculue couldn't solve B any other way but guess and check/logic x=4.5

**6th Grade Grammar**

Underline the form of to do or to have in the sentence. Today, many do their best to learn about Einstein's work. Also, what does the "to do" and the "to have" mean?

**HSM210**

Mrs Sue, Sorry to keep bothering you ! I have once more corrected the four answers . Do you mind checking them again. I so hate these assignments as I have such a hard time. Thank you so much for looking over my answers for me. 8. The victims’ rights movement developed ...

**math**

how do you solve for x using logs: [(a + b)^x]/b^x I am not sure of the steps to get there.

**HSM210**

Mrs Sue I corrected the answers that you said I had wrong in my assignment . Do you mind checking these for me again to see if I corrected them . Thank you so much for your help. 1. The Supreme Court has a greater obligation to protect the rights of victims than those of ...

**HSM210**

Mrs Sue do you mind checking my answers for me please? I have been working on this assignment for several days. The following activity helps you sharpen your skills in recognizing deceptive reasoning. The statements below are derived from the viewpoints in this chapter. Beside...

**Chemistry**

does postassium nitrate have a high or slow conductivity

**Chemistry**

sorry i mean which reactant

**Chemistry**

if 8.50grams CH4 reacts with 15.9grams of oxygen gass which of the prdocut is the excess and which is the limiting.

**Chemistry**

i got the mass of aluminum chloride to be 42.7

**Chemistry**

in 25grams of aluminium oxide reacts with 50grams aquoues hyrdogen chloride what is the mass of aluminum chloride produced?

**6th Grade Math**

Thanks!!!

**6th Grade Math**

Estimate a range for each sum. 3.89 + 42.71 + 12.32 I don't understand what to do for "estimating a range".

**earth science**

what are the landscape regions that the hudson river flows through

**chemistry**

how do you balance the equation __Al+__CuO=>__Al2O3+__Cu

**Business**

Mr Jones intends to retire in 20 years at the age of 65. As yet he has not provided for retirement income, and he wants to set up a periodic savings plan to do this. If he makes equal annual payments into savings account that pays 4% interest per year, how large must his ...

**ELLS**

Do you know anything about English Language Learners?

**6th grade Math**

thanks!

**6th grade Math**

The gas tank of your parents car holds 12.9 gallons of gas. Because their car averages 27.8 miles per gallon, how many times will they have to fillup the gas tank to drive to cincinnati and back? From Detroit, Michigan to Cincinnati, Ohio = 264.1 miles.

**Calculus**

a) prove that the function x^3 + 9x^2 +33x assumes the value -8 at least once b)using the mean value theorom or rolle's theorom - no other methods will be accepted - prove carefully that x^3 + 9x^2 + 33x takes on the value -8 at most once

**Math -- 6th Grade**

Thank you drwls!

**Math -- 6th Grade**

The sum of two decimal numbers is 5.3. Their difference is 1.7, and their product is 6.3. What are the two numbers? Does the product have anything to do with getting the answers?

**6th grade Math**

Thank you Bob!

**8th grade math**

55 mhp to 70 mhp

**physics**

CBA

**Economics**

U.S. antitrust enforcement policies have focused on 1) Enforcing market codes of ethics 2) Preventing "golden parachutes" 3) preventing price fixing arrangements 4) forcing firms to produce output at the point where P=MC 5) breaking up any firm with more than 10 ...

**comm arts**

when do you use homophone besides or except? Ican attend the meeting if it is scheduled any day of the week ..... Friday. What shoul I use. except or besides? Thanks

**Algebra**

trnslate to na algebraic expression a number divided by 15

**math**

solv the inequality: 1. 7-3x [is less than or equal to] 22 ---> x [is greater than or equal to] -5 2. 4x-2/3 [is greater than or equal to] 1/3 ---> x [is greater than or equal to] 3/5 are these correct??

**chemistry**

Q1) 5 liters of Butane gas (C4H10) is reacted with plenty of oxygen at 27 oC and 1 atm to produce carbon dioxide and water vapor. Calculate the following: 1- The volume of CO2 produced at 1 atm and 400 oC. 2- The mass of H2O vapor produced. 3- The mol % of the products. Given...

**9th grade**

@bobpursley so you mean we have to do a factor tree for 1000 numbers?!

**math**

Find an angle between 0 and 2Ð that is coterminal with given angle. 1. -7Ð /3 2. 10 3. 51Ð /2

**math**

Find an angle between 0 degree and 360 degree that is coterminal with given angle. a. 361 degree b. -100 degree c. 1270 degree

**council**

what is a good speech of secretary and vice presidents: this is what secretary it does attend council meetings take pictures at school functions distribute and collect surveys at school funtions and from classrooms participate in council activities vice president attend ...

**math**

27 / (5+4) * 19 = 27 / (9) * 19=3*19=57. Mom is right.

**math**

it is: -y/x* (2x+y)/(2y+x) let me now if you need more details.

**Social Studies**

thank you!

**Social Studies**

Yes. Can anyone help me?!?!?!?!? Help!!!!!!!!!!!!!!

**Social Studies**

I did but i can not find anything.

**Social Studies**

I need help finding a current event. The topic is A Famous Person Who Has Done Some Type Of Charitable thing. The article can be anywhere from last thursday to today. Thank You!

**math115**

The electricity costs of a buisness increased from $15,000 in one year to $16,000 the next. To the nearest whole percent what was the rate of increase?=7% Write the following as a common fraction or mixed number write in lowest terms 5.035 = 5 7/200

**math115**

thank you

**math115**

Let me try it this way I am dividing 30/49 by 16/21 or 30/49 dividing by 16/21= 45/56

**math115**

divide 30/49 divide 16/21= 45/56 a triangle has a base 15ft and an altitude of 8ft find the area =60ft^2

**Physics**

You are correct. I had the EXACT same Physics problem and got them correct.

**Math**

find mean, median and is mean or median more useful representation 25,29,30,30,30,31,33,34,40,41,46,63 mean 36 median 32 more useful 32

**Math**

find median 4,5,6,8,11,17 answer 7 find mean and median 68,69,71,75,76,76,81,82,86,88,93,94,95,95,96 answer mean is 83 median is 82 ?

**Math**

evaluate |-24|-|-22| answer -2? -|-618|answer -618 3-|7-9|answer 5? ?

**Math**

determine max and min value 3,- 36/7,-1,-2/3,5/4,-5,26/9 answer max3 min-5 ? put in asending order -2/9,-1/9,3/7,5/9,1/8

**Math**

add -4/5+{-3/4} simple form 1 1/5

**math**

Two circles of radius 4 are tangent to the graph y^2=4x at the point (1,2). Find the equations of the two circles.

**math**

Find (f + g)x, (f-g)x, (fg)x, and (f/g)x and their domains. f(x)=¡î(9-x©÷),g(x)=¡î(x©÷-4)

**math**

Find (f + g)x, (f-g)x, (fg)x, and (f/g)x and their domains. f(x) = ¡î(9-x©÷), g(x) = ¡î(x©÷-4)

**Math**

How much space (in ft³ ) will be taken up by the 458 balloons.

**Math**

Height: The volume of a cone is 100 in³. Find a function that models the height h of the cone in terms of its radius r.

**Math**

Minimizing Sum: Find two positive numbers whose sum is 100 and the sum of whose squares is a minimum.

**Math**

Maximizing Area: Among all rectangles that have a perimeter of 20 ft, find the dimensions of the one with the largest area.

**math**

Height: The volume of a cone is 100 in^3. Find a function that models the height h of the cone in terms of its radius r.

**math**

A woman 5 ft tall is standing near a street lamp that is 12 ft tall. Find a function that models the length L of her shadow in terms of her distance d from the base of the lamp.

**geometry**

Find a function that models the area A of a circle in terms of its circumference C.

**math**

A young man spent 1/4 of his allowance on a movie. He spent 11/18 of the remainder on after-school snacks. Then from the money remaining, he spent $3.00 on a magazine, which left him 1/24 of his original allowance to put into savings. how much of his allowance did he save?