Monday

October 24, 2016
Total # Posts: 930

**Chemistry**

Calculate the final temperature of a mixture of 200.0g of ice initially at -16.5 Celsius and 406.0g of water initially at 84.5 degrees Celsius.

*November 8, 2012*

**Chemistry**

The flame in a torch used to cut metal is produced by burning acetylene(C2H2) in pure oxygen. Assuming the combustion of 1 mole of acetylene releases 1251kj of heat, what mass of acetylene is needed to cut through a piece of steel if the process requires 36.658 x 10^4 kj of heat?

*November 8, 2012*

**Chemistry**

Which of the following gases will effuse through a hole in a balloon fastest? a.Kr b.NO c.N2O d.NO2 e.ArNO2

*November 6, 2012*

**Chemistry**

What is the root-mean-square speed of N2O at 25°C?

*November 6, 2012*

**Chemistry**

The density of an unknown gas is 1.72 g/L at 750.0 torr and 30.0°C. Which of the following could be the unknown gas? a. CS2 b. NO c. N2O d. NH3 e. N02

*November 6, 2012*

**Chemistry**

Which of the following reactions will result in a reduced total pressure? a. CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) c. 2HI(g) → H2(g) + I2(g) b. 2N2O(g) → 2N2(g) + O2(g) d. 2H2(g) + O2(g) → 2H2O()

*November 6, 2012*

**Chemistry**

How many moles of propane are contained in a 5.00 L tank at 450 torr and 25°C?

*November 6, 2012*

**Chemistry**

In an experiment, 25.0 mL of a gas with a pressure of 1.00 atm is contained in a balloon at 25.0°C. The balloon is then cooled to 5.0°C, and the pressure is found to be 0.750 atm. What is the volume of the gas under the new conditions?

*November 6, 2012*

**Chemistry**

Iron(III) oxide reacts with carbon monoxide gas to form solid iron metal and carbon dioxide gas: Fe2O3 + 3 CO --> 2 Fe + 3 CO2 If you begin the reaction with 84.34 g of iron(III) oxide and 68.87 g of CO, which reactant will be in excess at the end of the reaction and how ...

*November 5, 2012*

**Chemistry**

Which one of these samples contains the smallest number of molecules? a. 1.0 L of H2 at STP (0°C and 1atm) d. 1.0 L of N2 at 0°C and 800 torr b. 1.0 L of N2 at STP e. 1.0 L of He at STP c. 1.0 L of H2 at 20°C and 760 torr

*November 4, 2012*

**Chemistry**

Methanol (CH4O) is converted to bromomethane (CH3Br) as follows: CH4O + HBr --> CH3Br + H2O If 12.23 g of bromomethane are produced when 5.00 g of methanol is reacted with excess HBr, what is the percent yield?

*November 4, 2012*

**Childhood Education**

How does poverty relate to a child's risk for inadequate health and well-being?

*November 1, 2012*

**Childhood Education**

What items would you first look for to determine whether lead is present in the environment where children are present?

*November 1, 2012*

**Childhood Education**

Can anyone answer this question? Compare the environment for toddlers with one suitable for infants. How are the areas similar? How are they different?

*October 31, 2012*

**Childhood Education**

Compare the environment for toddlers with one suitable for infants. How are the areas similar? How are they different?

*October 31, 2012*

**Childhood Education**

Compare the environment for toddlers with one suitable for infants. How are the areas similar? How are they different?

*October 31, 2012*

**Organic Chemistry**

An expanded structural formula shows all the atoms of the molecule and all the bonds between the atoms in the molecule. Draw the expanded structural formula for 1,3-dichlorocyclopentane. Draw the structure by placing atoms on the grid and connecting them with bonds. Include ...

*October 30, 2012*

**english-dr.faustus**

the answer was B

*October 22, 2012*

**english-dr.faustus**

the warning Dr.Faustus teaches is? A-the devil is evil B-do not wish for more than heavenly power permits C-the end will justify the means D-both A and C

*October 22, 2012*

**math**

the product of a 1 digit number and a 2-digit number number is 284 what is the awnser

*October 20, 2012*

**Pre-Algerbra**

In which quadrant does the point lie? Write the coordinates of the point. Point B A. quadrant II; (–2, –4) B. quadrant III; (2, 4) C. quadrant III; (–2, –4) D. quadrant IV; (–4, –2)

*October 17, 2012*

**Chemistry/Quantitive Anaylsis**

Determine the absolute and percent relative uncertainty expressing the result in the correct number of significant digits a.) 6.2 (+-0.2)-4.1(+-0.1) b.)[9.23(+-0.03)][4.21(+-0.20}/21.1(+-0.2) c.)log[3.1415(+-0.001)] d) log[(0.104(+-0.0060)]^1/2 /0.0511(+-0.00090]

*October 14, 2012*

**Chemistry/Quantitive Anaylsis**

Before determining the amount of sodium carbonate in a sample by titration with standard hydrochloric avid the anaylst decide to check the procedure by analyzing a known sample of 98.75 (w/w)% purity. Five replicate determinations of the known gave the following results: 98.71...

*October 14, 2012*

**Chemistry**

The amount of energy released by burning a fuel source, measured in energy per mass, is called the fuel value. If all the energy obtained from burning 1.30 pounds of methane (fuel value is 11.97 kcal/g) is used to heat 122.0 kg of water at an initial temperature of 21.1 °C...

*October 11, 2012*

**college stats**

A study wants to examine the relationship between student anxiety for an exam and the number of hours studied. The data is as follows: Student Anxiety Scores Study Hours 5 1 10 6 5 2 11 8 12 5 4 1 3 4 2 6 6 5 1 2 Why is a correlation the most appropriate statistic? What is the...

*October 8, 2012*

**Early childhood education**

Awesome! Thanks!

*October 3, 2012*

**Early childhood education**

Special educational services for young children with disabilities: a. Cannot be enforced through laws. b. depend on parent efforts. c. do not involve the Head Start Program. d. are rooted in federal legislation. I'm thinking D is the correct answer?

*October 3, 2012*

**Exceptional Children**

Most early childhood professionals children’s agree that the terms inclusion and mainstreaming: A. Both refer to exceptional children’s participation in the general education curriculum. B. Mean the same thing. C. Are two different concepts. D. Both refer to programs...

*October 3, 2012*

**English**

I had to write a paragraph about a personal experience of mine with no passive verbs. When I submitted mine my teacher told me it was almost correct but not right yet. Could you tell me a list of passive verbs?

*October 1, 2012*

**Computers**

What are calculations entered into a spreadsheet called? Formulas? Or Values? I'm thinking its formulas but Values talks about calculations on a spreadsheet too.

*September 27, 2012*

**geometry**

PM is the median of trapezoid KLNO. If ON = 24 centimeters and KL = 12 centimeters, which is the length of PM

*September 26, 2012*

**math**

You need to prepare 180g of a 10% cream using 30% stock cream base.how much is needed for each

*September 20, 2012*

**literary**

I need an example of connotation from the Star Wars series in the form of a quote.

*September 16, 2012*

**Bio**

Assume that a cell culture has a density of 108 cells/mL. You transfer 20 microliters (20 L) of this culture onto a microscope slide. How many cells do you expect will be in this 20 L drop you placed under the microscope?

*September 13, 2012*

**geometry**

Given letters gb and gf how do you write a mathematical to compare their measures?

*September 7, 2012*

**Statistics**

An important measure of the performance of a locomotive is its "adhesion," which is the locomotive's pulling force as a multiple of its weight. The adhesion of one 4400-horsepower diesel locomotive model varies in actual use according to a Normal distribution ...

*September 5, 2012*

**Statistics**

An important measure of the performance of a locomotive is its "adhesion," which is the locomotive's pulling force as a multiple of its weight. The adhesion of one 4400-horsepower diesel locomotive model varies in actual use according to a Normal distribution ...

*September 5, 2012*

**Math**

9.45*10^15

*September 5, 2012*

**physics**

If you walk for 1.66min at a speed of 1.22m/s and then run for 1.66min at 3.05m/s along a straight track, what is the average velocity?

*August 22, 2012*

**Social Studies**

its not a or b cause i took the test the answer is cold war spending

*August 15, 2012*

**Math- STATS 218**

When the following hypotheses are being tested at a level of significance of aH0: m 100 Ha: m < 100 the null hypothesis will be rejected if the test statistic Z is a. >Z b. >Z c. <Z d. <100

*July 27, 2012*

**critical reading**

Elaborate comparisons which are used by advertisers are usually _____. A)fallacies of evidence. B) fallacies of language. C)newsworthy. I think it is B, is this correct?

*July 12, 2012*

**Math**

Calculate the percentage strength of hydrocortisone if you combine 30 g of 1%, 45 g of 0.5%, and 15 g of 2%. Round to the hundredth.

*July 6, 2012*

**Math**

Androgel is available in 1% strength. A provider prescribed it for a patient but would like to minimize side effects by starting treatment at a lower 0.3% strength. How much androgel should be added to a base gel to prepare 15 g of the desired strength?

*July 6, 2012*

**Phamacy School**

What is the percentage strength of tretinoin gel when you combine 15 g of 0.025% and 30 g of 0.01%?

*July 6, 2012*

**MATH**

What is the percentage strength of tretinoin gel when you combine 15 g of 0.025% and 30 g of 0.01%?

*July 6, 2012*

**MATH**

Calculate the percentage strength of hydrocortisone if you combine 30 g of 1%, 45 g of 0.5%, and 15 g of 2%. Round to the hundredth.

*July 6, 2012*

**MATH**

Calculate the amount of 8% acetic acid needed to combine with water to make 600 ml of 3.5% acetic acid.

*July 6, 2012*

**math**

What answer did u get

*June 25, 2012*

**English III**

# 3 is B

*June 9, 2012*

**GEOMETRY**

if AB=5X+3 and BC=7x-9 what is the value of AC? using the addition segment postulate

*June 6, 2012*

**Stats**

I posted this question straight from the quiz, so I'm not sure why you're confused.

*May 26, 2012*

**Stats**

Find the number z (± 0.01) such that the proportion of observations that are less than z in a standard Normal distribution is 0.8 Find the number z (± 0.01) such that 59% of all observations from a standard Normal distribution are greater than z

*May 26, 2012*

**history **

Which system of Spanish government did haciendas replace? A. the encomienda B. popular sovereignty C. socialism D. coalitions

*May 25, 2012*

**algebra 2**

find the exact value using the unit circle cos 3.14/6

*May 24, 2012*

**geometry**

PLEASE HELP WITH A FEW QUESTIONS triangle ABC has side lengths 8, 15, and 17 do the side lengths form a pythagorean triple? the length of the hypotenuse of a 30-60-90 triangle is 7 find perimeter to approach the runway, a pilot of a small plane must begin a 10descent starting ...

*May 23, 2012*

**geometry**

I was looking for how to do proportions, i had forgot.

*May 23, 2012*

**geometry**

Thanks for the help on one problem

*May 23, 2012*

**Chemistry**

I need help with the Lewis Dot Structure. I'm so lost. The problems I have and need help with are 1) H2NCH3 2) C3H6 3)NO2-ion 4) H3CSCH2F 5) NCl3 6) H2NCOOH 7)C3H7OH

*May 23, 2012*

**History**

What were the causes of the War of 1812? Where did Republicans and Federalists stand on declaring and then fighting the war? What regional tensions did the war expose?

*May 22, 2012*

**Chemisty**

A 2.5 L volume of sodium hydroxide solution was prepared. The titrant was standarized against primary standard oxalic acid dihydrate, H2C2O4*H2O(molar mass is 126.06) if a 0.4774g sample of the prmiary standard consumed 31.94mL of the base solution in reaching the ...

*May 9, 2012*

**Chemistry**

A Student Performing a lab weighed a 1.0993g sample, containing an unknown KHP, which required 18.06mL of 0.1879M NAOH to reach the phenolphtalein endpoint. a) How many moles of base were consumed by the KHP in this sample? b) How many grams of KHP were titrated? c)What is the...

*May 9, 2012*

**english **

According to the Introduction, who encouraged Mary Shelley to expand Frankenstein into a full-length novel

*May 8, 2012*

**statistics**

Whats the difference between creating a z score from a single score and creating one fron a sample mean?

*April 30, 2012*

**English 4**

the choices are: A-the birds were flying over the sea in a straight formation B-the seas were rough C-there was a faint outline of the old man in the crescent of the new moon D-all of the above

*April 30, 2012*

**algebra**

How would I show my work for: 3-2(3)+2(4)+1

*April 28, 2012*

**Intermediate Algebra (college)**

Use the properties of logarithms to condense the expression 1/3[ln(x - 6)- 4 ln y - 2 ln z]

*April 26, 2012*

**Precalc**

if sine theta=.3416 and theta is in quadrant I what is cos theta/2? Using double angle identities.

*April 26, 2012*

**statistics**

I guess 100 is the highest the mean is 30.9 and the standard deviation 2.08 it just says children below the 30th percentile

*April 19, 2012*

**statistics**

Children below the 30th percent are in need of special assistance assistance what raw score makes the cut off score for these children?

*April 19, 2012*

**Physics**

Two parallel wires conduct equal currents in the same direction. (a) At a point in the plane of the wires midway between them, do the individual fields of the wires cancel or reinforce each other? (b) At a point far away from the wires, do their individual fields tend to ...

*April 17, 2012*

**AP Chemistry**

A voltaic cell is constructed that uses the following half-cell reactions. Cu+(aq) + e- Cu(s) I2(s) + 2 e- 2 I -(aq) The cell is operated at 298 K with [Cu+ ] = 2.3 M and [I - ] = 3.3 M. (a) Determine E for the cell at these concentrations. (b) If [Cu+ ] were equal to 1.0 M, ...

*April 16, 2012*

**AP Chemistry**

A voltaic cell is constructed that uses the following half-cell reactions. Cu+(aq) + e- Cu(s) I2(s) + 2 e- 2 I -(aq) The cell is operated at 298 K with [Cu+ ] = 2.3 M and [I - ] = 3.3 M. (a) Determine E for the cell at these concentrations. (b) If [Cu+ ] were equal to 1.0 M, ...

*April 16, 2012*

**CHEM**

Given the equation 2C8H18 + 25O2 = 16 CO2 + 18H2O: The combustion of octane produces carbon dioxide and water. If you start with 10.0 moles of octane, what mass of water (in grams) would you expect to produce?

*April 3, 2012*

**Chemistry 1201**

thankyou so much! i got 3.65*10^25

*March 28, 2012*

**Chemistry 1201**

A solution of ammonia and water contains 1.00×1025 water molecules and 5.50×1024 ammonia molecules. How many total hydrogen atoms are in this solution?

*March 28, 2012*

**chemistry**

Calculate the enthalpy change for converting 10.0g of ice at -25 degrees Celsius to water at 80 degrees Celsius. The specific heats of ice, water, and steam are 2.09j/g degrees Celsius, 4.18j/g degrees Celsius, and 1.85j/g degrees Celsius. The enthalpy of fusion for water is 6...

*March 28, 2012*

**chemistry**

How do I do a question like this please help and explain it!! Calculate the pH of a buffer solution that contains 0.22 M benzoic acid (C6H5CO2H) and 0.24 M sodium benzoate (C6H5COONa). [Ka = 6.5 × 10-5 for benzoic acid] Round your answer to two places past the decimal.

*March 25, 2012*

**Chem 111**

A solution is prepared by mixing 499 mL of 0.19 M Tris·Base and 592 mL of 0.37 M Tris·Acid. What is the pH of this solution? [Ka(Tris·Acid) = 8.5 × 10-9] Round your answer to two places past the decimal. I can do basic pH questions but I am at a loss...

*March 25, 2012*

**math **

A town has a population of 32,000 in the year 2002; 35,200 in the year 2003; 38,720 in the year 2004; and 42,592 in the year 2005. If this pattern continues, what will the population be in the year 2016?

*March 10, 2012*

**geography**

Which region of southern grasslands in south america have rich deposits of oil and bauxite?

*March 9, 2012*

**geography**

which region of the southern grasslands possesses rich deposits of oil and bauxite?

*March 9, 2012*

**Chemistry**

21 gCH3OH*(1 mol/32.01CH3OH)*(252.8/1 mol)

*March 5, 2012*

**Chemistry**

2CH3OH(g)->2CH4(g)+O2(g) Change in H=252.8 kJ

*March 5, 2012*

**Chemistry**

So far my equation is 21 gCH3OH*(1 mol/32.01CH3OH)

*March 5, 2012*

**Chemistry**

Calculate the amount of heat transferred when 21.0 of CH3OH(g) is decomposed by this reaction at constant pressure.

*March 5, 2012*

**Chemistry**

A gaseous reaction occurs at a constant pressure of 50.0 atm and releases 69.8 kJ of heat. Before the reaction, the volume of the system was 8.80 L . After the reaction, the volume of the system was 2.80 L . Calculate the total internal energy change, change in U , in kilojoules.

*March 5, 2012*

**Adv. Function math**

How would you set up this problem if instead of using 1000 feet of fencing, only 750 feet of fencing is used? Solve the problem to find the maximum area..

*February 29, 2012*

**Finance**

Say that you purchase a house for $270,000 by getting a mortgage for $235,000 and paying a $35,000 down payment. If you get a 15-year mortgage with a 8 percent interest rate, what are the monthly payments?

*February 27, 2012*

**Physics Please Help!**

A solid disk with a mass ok 100 kg and radius of 0.2m turns clockwise through an angular displacement 10 rad when starting from rest attain its maximum angular speed of 1 revolution every 0.5s. How much time did it take for the disk to go from rest to maximum angular speed?

*February 21, 2012*

**Physics**

A solid disk with a mass ok 100 kg and radius of 0.2m turns clockwise through an angular displacement 10 rad when starting from rest attain its maximum angular speed of 1 revolution every 0.5s. How much time did it take for the disk to go from rest to maximum angular speed?

*February 21, 2012*

**PHYSICS**

A solid disk with a mass of 100kg and a radius of 0.2m, turns clockwise through an angular displacement 10 rad when starting from rest to attain its maximum angular speed, of 1 revolution every 0.5s. What is the angular acceleration that the wheel experienced in order to ...

*February 20, 2012*

**Physics**

A solid disk with a mass of 100kg and a radius of 0.2m, turns clockwise through an angular displacement 10 rad when starting from rest to attain its maximum angular speed, of 1 revolution every 0.5s. What is the angular acceleration that the wheel experienced in order to ...

*February 20, 2012*

**algebra**

use any three of the digits 2,3,4 and 6 to form an 8 digit factor and a two didgit factor with a estimated product that is between 140 and 250

*February 18, 2012*

**phi 103**

no fallacy committed

*February 12, 2012*

**Physics**

ohh okies thanks for clearing that up (:

*February 12, 2012*

**Physics**

i mean.. mr^2w+Iw = mr^2w+Iw ... which is equivalent to L+L = L+L

*February 12, 2012*

**Physics**

I don't really understand we use I1w1=I2w2? but according to your equation its mr^2+Iw = mr^2+Iw ... which is equivalent to I+L = I+L <-- i don't get this part? and the answer is 0.568 rev/s which according to your way is right but its 19 instead of 29.

*February 12, 2012*

**Physics**

A turntable of radius 2m rotates freely about a fixed vertical axis. A child 19 kg is standing on the turntable right at the outer edge and the system is initially rotating at an angular speed of 0.5 rev/s. The child then moves to position 1m from center of the turntable. what...

*February 12, 2012*