Wednesday

September 28, 2016
Total # Posts: 413

**Chemistry**

1. Write a balanced equation : 2H^2O^2---O^2+ 2H^2O 2. Find the molar mass (g/mol) of each: 34.02 32.00 18.02 3. Divide grams water by the molar mass of water: .77g (1mol/18.02g) ~ .0427 mols 4. Use the mole ratios to find the number of hydrogen peroxide moles: 2H^2O^2---O^2+ ...

*April 10, 2012*

**math**

a jar contains 27 blue blocks 18 red blocks 12 orange blocks and 43 green blocks You put your hand in the jar and without looking pull out a block. About what fraction on the time would you expect to get a red block?

*April 10, 2012*

**Physics**

How many kcal of heat are required to vaporize 25.0kg of water at 100°C?

*April 2, 2012*

**Physics**

Find the increase in Volume of 50.0L of acetone when heated from 40.0°C to 75.5°C.

*April 2, 2012*

**Physics**

How many Btu of heat must be added to 900lbs of steel to raise its temperature from 20.0°F to 500°F? Specific heat of steel .115Btu/lb°F

*April 2, 2012*

**Physics**

A Brass rod 50.0 cm long expands 0.0734 cm when heated. Find the temperature change.

*April 2, 2012*

**Physics**

A 100 kg steam boiler is made of steel and contains 200 kg of water at 5.00°C. How much heat is required to raise the temperature of both the boiler and water to 100°C? The specific heat of Steel is 0.115kcal/kg°C. The specific heat of Water is 1.00kcal/kg°C

*April 2, 2012*

**math**

if you have a piece of string 11 ft. long and you cut it into 15 equal pieces how long will each piece be?

*February 13, 2012*

**Physics**

A ball is thrown horizontally from the top of a building 21.6 m high. The ball strikes the ground at a point 123 m from the base of the building. Find the x component of its velocity just before it strikes the ground. Find the y component of its velocity just before it strikes...

*February 4, 2012*

**Math**

Pamela and David walk on the same track. It takes Pamela 9 minutes and David 6 minutes to walk one lap. If they start walking at the same time, how many laps will each have walked when they cross the starting point together for the first time?

*February 1, 2012*

**math**

If I have a 66% in algebra Android we took a exam that's worth 20% of our grade Android I got a 54% on the multiple choice what would my average grade be?

*December 14, 2011*

**algebra 2nd grade**

10

*December 12, 2011*

**Career planning**

I chose D- All of the above

*December 6, 2011*

**Math**

I'm so lost.

*November 15, 2011*

**geometry**

Which of the following statements is true?Select one of the options below as your answer:A. A 25o angle is congruent to a 25o angle. B. Two intersecting lines form two pairs of congruent angles. C. It is possible for congruent angles to add up to 90o. D. All of the above are ...

*November 8, 2011*

**9th grade Biology**

4. After the temperature reaches 33 degrees Celcius, the rate of photosynthesis declines. Using knowledge of enzymes, explain why this happens. 6. As the amound of CO2 increases, what would happen to the rate of photosynthesis? And as the amount of CO2 increases, would the ...

*October 27, 2011*

**Algebra 2**

Find the coordinates of the vertices of the parallelogram with sides that are contained in the lines with equations y=3, y=7, y=2x, y=2x-13

*October 23, 2011*

**Math**

2989/7*2

*October 23, 2011*

**canyons,dunes,and deltas SCIENCE**

Weathering

*October 13, 2011*

**Physics**

A bicycle is moving at a constant speed of 12m/s as it covers a distance of 200m. it then applies its brakes and stops over the next 350m. how much time doe sthis total motion take?

*October 7, 2011*

**Math**

?? huh

*September 29, 2011*

**Math**

6 ways

*September 29, 2011*

**Geometry**

how do you solve using midpoint equation if you only have one pair of points? like to use midpoint equation you usually get two points (4,3) and (5,2) but ive been given only one point (3,1). how do i solve for midpoint with only one set of points? help please

*September 29, 2011*

**science**

What keeps proteins within the bilayer?

*September 27, 2011*

**chemistry 1 **

From data below, calculate the total heat (J) needed to convert 0.757 mol of gaseous ethanol (C2H6O) at 151°C and 1 atm to liquid ethanol at 25.0°C and 1 atm. Boiling point at 1 atm 78.5°C cgas 1.43 J/g·°C cliquid 2.45 J/g·°C ΔH°vap ...

*September 27, 2011*

**physics**

a quarterback throws a pass to a receiver. the release point for the football is 1.8 m above the ground. he projects the ball with a speed of 20 m/s at an angle of 40 above the horizontal. If the pass falls incomplete, how long is it in the air? If the pass falls incomplete, ...

*September 20, 2011*

**Mathematics**

800

*September 19, 2011*

**Math**

simplify 14/22

*August 18, 2011*

**Math**

simplify 64/76

*August 18, 2011*

**Math**

simplify 13/17

*August 18, 2011*

**Math**

Simplify -17/21.

*August 18, 2011*

**chemistry**

A piece of copper wire has a density of 8.9 g/cm3. What is the density of a chunk of copper that has a mass of 250 grams?

*June 25, 2011*

**geometry**

line segment AB and XY are congruent. if AB=5N-8 and XY= 2n+19 what is the legth of AB?

*June 22, 2011*

**chemistry**

what are some examples of suspensions?

*June 1, 2011*

**MATH**

20

*June 1, 2011*

**Chemistry**

Will you check this answer for me? the half-life of strontium-87 is 2.8hr. What percentage of this isotope will remain after 8 hours and 24 minutes? ?? 34%

*May 25, 2011*

**Pre-Calc**

A hall 200 feet in length is to be designed as an ellipse if the foci are 35 feet from the center. How high will the ceiling be from the center?

*May 11, 2011*

**Pre-Calc**

A mirror is in the shape of a paraboloid. If a light source is 6 feet from the base along the axis of symmetry and the opening is 12 feet across, how deep should the mirror be?

*May 11, 2011*

**math**

Colin is working to earn some money for a new cd player. On Saturday he earned half as much as he did on Sunday, but twice as much as he did on Friday. During those three days he earned $70. How much did he earn each day?

*April 11, 2011*

**5th grd math- metric conversion**

30m=6000

*March 7, 2011*

**probability**

I was asked to find the probaility if a board game uses the deck of 20 cards. And find how many have the number 3. I came up with 4/20 and was told that I'm on the right track but I need to find P(3 and 3) with replacement and without replacement. What does this mean?

*February 14, 2011*

**Probability**

How do I determine the probability of selecting a card greater than 9 or a black card?

*February 8, 2011*

** probability **

The odds against Paul Phillips winning the 100 yard dash are 7:2. Determine the probability that: • a) Paul wins. • b) Paul does not win. How do I set this up to find out the equation/answer?

*February 1, 2011*

**chemistry**

4. Use the pressure of the butane gas (your answer from question #3 above), along with the temperature and volume recorded in the lab, to determine the moles of butane gas collected in the lab. You will use the ideal gas law (and the ideal gas constant, R) for this calculation...

*February 1, 2011*

**Math**

Would the set up be [(p-->q)^~p]-->~q

*January 21, 2011*

**Math**

If you pass general chemistry, then you can take organic chemistry. You pass general chemistry. ˆ You can take organic chemistry. Let P = you pass general chemistry Let Q = you can take organic chemistry I came up with P - >Q P therefore Q But my set up is wrong...

*January 21, 2011*

**precalc**

f(x)=Log1/3^(9x)find the domain and range.

*January 14, 2011*

**chemistry**

consider the following reaction: 2C2H6(g)+7O2 (g)-->4CO2(g)+6H2O (g) delta H = -3120kJ If 3.00g of ethane are burned, how many kJ of heat are produced?

*January 13, 2011*

**chemistry**

consider the following reaction: C3H8 (g)+ 5O2 (g)--> 3CO2 (g)+ 4H20 (g) Delta H = -2440kJ The heat of formation of CO2 is -390 kJ/mol and the heat of formation of H2O is -240 kJ/mol. What is the heat of formation of propane?

*January 13, 2011*

**chemistry**

the following reaction is carried out in a bomb calorimeter: 4NH3 (g) +5O2 (g)-->4NO (g)+6H2O (g) The calorimeter constant is 45.0kJ/K. when 34.0g of NH3 are reacted in the calorimeter, the temp rises by 10 degrees C. What is the change in energy, delta E, for the rxn?"

*January 13, 2011*

**Math**

Time's 5

*January 13, 2011*

**Spanish**

when you are talking in past tense. for example: you went swimming yesterday.

*January 9, 2011*

**Chemistry-Help!!**

If I have 10mL of 1.0 M Ba(OH)2 solution and add it to 2.5L of water. What is the concentration of hydroxide ions in the diluted Ba(OH)2 solution?

*December 7, 2010*

**Chemistry-Confused!!**

You have 10mL of a 1.0 M Ba(OH)2 solution and add it to 2.5L of water. What is the concentration of hydroxide ions in the diluted Ba(OH)2 solution?

*December 7, 2010*

**MATH HELP!!**

what is the unit rate for 67.92 for 4gal

*December 6, 2010*

**Chemistry-urgent!**

Yes, but would that give me 63 mL or 250 mL. That's where I get confused.

*November 30, 2010*

**Chemistry-urgent!**

What volume of 2.5% (w/v) KOH can be prepared from 125 mL of a 5.0% KOH solution?

*November 30, 2010*

**Chemistry/Science - please help!**

An aqueous mixture containing starch (a colloid), NaCl, glucose, and albumin (a colloid) is placed in a dialyzing bag and immersed in distilled water. Which of the following correctly describes the location of the indicated substance after dialysis? A-albumin, inside B-starch ...

*November 30, 2010*

**Chemistry**

I'm having trouble with molarity. What is the molarity of a KCl solution made by diluting 75.0 mL of a 0.200 M solution to a final volume of 100.0 mL?

*November 29, 2010*

**Math**

Find the present value of the annuity necessary to fund the withdrawal of $600 per month for 10 years, if the annuity earns 2% per year and if there is to be $10,000 to be left in the annuity at the end of the 10 years. (Assume end-of-period withdrawal and compounding at the ...

*November 18, 2010*

**Math**

Find the present value of the annuity necessary to fund the withdrawal of $600 per month for 10 years, if the annuity earns 2% per year and if there is to be $10,000 to be left in the annuity at the end of the 10 years. (Assume end-of-period withdrawal and compounding at the ...

*November 18, 2010*

**socail studies**

new england colonies 2. what? what happend to the coloonists at roanoke? whta happend to the colony at sagadaco? 5. where? where was roanke? where was sagadahoc? where was james feild?

*October 28, 2010*

**social studies**

What was the name of William Lloyd Garrison's anti-slavery newspaper.

*October 27, 2010*

**math **

what is the perimater of a 90 degree angle multiply by 2 a 17 multiply that answer by 7 add 90 and subtract 23.

*October 27, 2010*

**writing**

My teacher said,write 10 sentences 5 for each Paragraph..she said here is your topic. If you would write a speech what would you write it about. Now im not writing a speech im writing i i would write a speech what would i write it on im havinc alot of trouble help please....???

*October 26, 2010*

**math**

if you used 2 hundreds, 18 tens, and 4 ones to model a number. what number did you model?

*October 21, 2010*

**Chemistry**

A 112 mL solution of 0.351 M HCl is added to 52.0 mL of 0.161 M HCl. What is the new concentration of HCl?

*October 21, 2010*

**Chemistry**

what is the concentration of Cl- after adding 250 mL of 0.10 M AlCl3 to 250 mL of 0.30 M Ca(NO3)2

*October 21, 2010*

**advanced history**

I need a website that will tell me everything about The Independence Debate:Consequences for the Colonies?

*October 19, 2010*

**Chemistry**

4.90g Ba

*October 14, 2010*

**English**

How do you fix this pronoun agreement. The first theme that the author demonstrates is to not let people with a disability feel abnormal, but for them to use the abilities that they have to help them build their self-confidence.

*September 28, 2010*

**Quick ?**

I doing a sample lesson plan for my english class. I want to show a movie that realtes to the book that were reading and the movie is 106 minutes. I teach each class for 50 minutes a day. How many days would it take to finish the movie and how long is 106 minutes?

*September 27, 2010*

**Art**

Why is important for children to draw pictures of things that scare them (otherwise what does the child learn from this?

*September 26, 2010*

**math**

If you had a fraction strip folded into tenths what fractional lengths could yu measure with the strip?

*September 23, 2010*

**math**

The tread life of a particular tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 2000 miles. What is the probability that a randomly selected tire of this brand will last longer than 58,000 miles? A.0.7266...

*September 18, 2010*

**alegebra**

i don't know any i need help asap!

*September 14, 2010*

**science**

A ball is dropped from a cliff and has an acceleration of 9.8 m/s2. How long will it take the ball to reach a speed of 24.5 m/s?

*September 7, 2010*

**Math**

Mike can mow a lawn in 3 hours. Paul can mow the same lawn in 2 hours. How long would it take both of them working together to mow the lawn? The answer is suppose to be 20/9. This is what I did and I get 9/20. What am i doing wrong? 1.4x+1/5x=1 which gives u 9/20. I'm so ...

*August 31, 2010*

**Math**

Solve each inequality algebraically. |2x-1|-2<3 I don't understand how the answer is -2<x<3

*August 30, 2010*

**Math**

A student scored 65, 80, 74 on the first three tests during the term. What does the student need to score on the fourth test to ensure and an average score that is above 75?

*August 27, 2010*

**math**

How do I start off this equation? Using correct mathematical notation and symbols, express the following in set builder notation: Z = {4, 5, 6, 7, 8, 9, 10, 11}

*August 18, 2010*

**math **

Given these sets: A = {1, 2, 3, 4} B = {3, 4, 5, 6, 7} C = {3, 5, 7, 9} List the elements of this set C ¿ (A u B) Do I list the numbers in C that is not in A and B?

*August 15, 2010*

**math**

Sealing a Gym Floor A gymnasium floor has an area of 2400 square yards. Each gallon of floor sealant covers an area of 350 square feet. How many gallons of sealant are needed to cover the gymnasium floor? should the equation be set as 2400 sq. yards = 7200 sq. feet 7200 sq ft...

*August 11, 2010*

**college mathematics**

how do I set up an equation for this? Lisa has $215 saved. She plans to save $125 every month so that she can have enough money to buy a new sofa. The sofa costs $1498, including tax. How many months will she need to save to be able to buy the sofa?

*August 11, 2010*

**college mathematics**

1-1=0 0-2=-2 -2-3=-5 -5-4=-9 -9-5=-14 (would it be this)

*August 11, 2010*

**college mathematics**

Use inductive reasoning to predict the next three numbers in the sequence. 1, 0, -2, -5, -9,

*August 11, 2010*

**algebra**

Use inductive reasoning to predict the next complete line in the pattern. 10 × 12 = 11 × 13 - 23 12 × 14 = 13 × 15 - 27 14 × 16 = 15 × 17 - 31

*August 9, 2010*

**Science**

sososososososososososos

*May 16, 2010*

**algebra1**

The sears tower in Chicago is 1,454 feet high. suppose you take a sheet of paper and fold it once in half, than fold it in half again,and keep folding it over and over again. How many times would you have to fold it to create a piece of paper that is higher than the sears tower?

*May 6, 2010*

**social studies**

What three countries border Egypt?

*April 13, 2010*

**Math**

in a subdivison, 67% of the homes have detatched garages, 32% have a patio & 13% have both. What is the probability that a house has a patio if u know that it has a detached garage?

*March 25, 2010*

**physics**

im trying to find the speed of a tyrannosaurus rex by alexanders froude number. sp= (square root of)leg length x gravity/ froude number sp=(square root of) 3.5 x 9.8 / 11 i get 1.76 but a t rex cant run/ walk at 1.76 m/s or km/h nothing fits

*February 26, 2010*

**Math**

Ya it says How many ounces of each solution should be mixed to prepare the desired perscription? Why is there a 50 in parentheses next to the .54? So once I solve for x what do I do next?

*February 26, 2010*

**Math**

A pharmacist is to prepare a 50 fluid ounce solution that contains 54% glucose. The pharmacy has a 30% solution and a 90% solution on hand. How many ounces of each solution should be mixed to prepare the desired perscription?

*February 26, 2010*

**Math**

x/2-3=x/5+1 The answer is suppose to be 40/3... I don't know how do this

*February 3, 2010*

**English**

why is it important to know the story elements when reading a text and writing a narrative

*February 1, 2010*

**English**

How do text and word help me understand the meaning of words while I read and write?

*February 1, 2010*

**Math**

How do you solve this equation? The answer is suppose to be -0.7 Thanx for you help. Greatly appreciated -5x\9=7/18

*January 29, 2010*

**Science**

yes it is B

*January 26, 2010*

**linear system problems**

the base of an isosceles triangle is one third the lenght of each congruent sides the perimeter of the triangle is 84 cm how long is the base?

*January 18, 2010*