# Posts by Lance

Total # Posts: 239

**Chemistry College**

A 79.1 g mixture of the compounds calcium chloride and sodium sulfide is 80.9 % by mass sodium sulfide. The compound sodium sulfide is 58.9 % by mass sodium. Calculate the mass (g) of sulfur in the mixture. thanks.

**Statistics**

A study on the amount of dye needed to get the best color for a certain type of fabric was conducted. The following data give the photometer readings for the color density of the fabric when the amount of dye used was 1% of the weight of the fabric. 13.2 11.5 12.9 13.0 11.7 10...

**Reposting Chemistry College**

Based on the balanced equation 4Na + O2 → 2Na2O calculate the number of Na2O formula units formed when 60 Na atoms and 10 O2 molecules react? Thanks.

**College Chem**

Based on the balanced equation 4Na + O2 → 2Na2O calculate the number of Na2O formula units formed when 60 Na atoms and 10 O2 molecules react? Thanks.

**College Chem**

Based on the balanced equation 4Na + O2 → 2Na2O calculate the number of Na2O formula units formed when 60 Na atoms and 10 O2 molecules react? Thanks.

**Chemistry**

The triation of 50.00 mL of 0.025 00 M MES with 0.100 0 M NaOH. MES is a weak acid with pKa=6.27. Compute Ve, first. Show what happens at the four stages of the titration: Va = 0,2,5,10,10.1,11,12, and 12.2 mL. I NEED HELP!!!!

**science**

a

**Chemistry**

A mixture of the compounds magnesium oxide and calcium sulfide contains 21.6999 g of magnesium oxide and is 51.3 % by mass magnesium oxide. The compound calcium sulfide is 44.400 % by mass sulfur. Calculate the moles of sulfur in the mixture. I'm not sure what I did wrong...

**College Chemistry**

I knew something was fishy about this question. Thank you!

**College Chemistry**

A mixture of the compounds sodium oxide and magnesium chloride contains 2.4182 g of sodium oxide and is 89.3 % by mass magnesium chloride. The sodium oxide is 74.200 % by mass sodium. Calculate the moles of oxygen in the mixture. Thanks in advance.

**ELA**

clans society club navy class livestock

**ELA**

All Collective nouns? festival family flock crowd parties army village company gallery

**ELA**

Is tourists a collective noun? Im not sure for that one

**ELA**

Yeah but we have to find some in a magazine and cut them out. Are these so far collective? Family and flock?

**ELA**

Is we they and them collective?

**ELA**

We have to find 20 collective nouns in a magazine. So far are all of these collective? 1.partners 2.Birds 3.Family 4.Amphibians 5.Crustaceans 6.builders 7.Immigrants 8.Animals 9.Grades 10.Services 11.packages 12.lodges 13.Members 14.Branches

**Physics**

A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of 8.15 m/s at an angle of 18.5o below the horizontal. It strikes the ground 3.30 s later. How far horizontally from the base of the building does the ball strike the ground? ...

**Physics**

F=ma F=4xa a= 8.0m/s / 2.0 s = 4.0 m/ss F=4kg x 4 m/ss = 16 kgm/ss kgm/ss = N (newtons) F=16 N

**algebra**

The half-life of 234U, uranium-234, is 2.52 105 yr. If 98.4% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

**can you please look over my answers? clauses**

Amanda bought a prom dress which she considered the most beautiful dress ever made. Adjective clause:Amanda bought a prom dress Word(s) modified:dress

**Social Studies**

In what city did Rosa Parks defy the rules of segregation?

**MATH**

A bag contains 5 slips of paper. On each slip is written the name of a member of the Avila family--Mr.Avila,Mrs.Avila,their son,or one of their 2 daughters. Find the probability of each outcome if you take a piece of paper out of the bag without looking. 1. The name of a ...

**Math**

A bag contains 5 slips of paper. On each slip is written the name of a member of the Avila family--Mr.Avila,Mrs.Avila,their son,or one of their 2 daughters. Find the probability of each outcome if you take a piece of paper out of the bag without looking. 1. The name of a ...

**Social Studies**

During the 1930's, Camden,New Jersey became the site of this first. It had a parking lot big enough for 400 cars. What was it?

**Social Studies**

The largest island in the world, locates near Canda is called______. I think it's Greenland

**Chemistry**

Boiling occurs when?

**Chemistry**

Carbon tetrachloride CCl4 contains carbon (EN = 2.5) and chloride (EN = 3.0). Because of this, CCl4 is:

**Inverse Variation**

y varies inversely as x. When y = 18, x = 6. Find the constant of variation and determine the value for y when x = 27

**SCIENCE**

D?

**SCIENCE**

Conservation of natural resources could include- A. the use of more renewable sources of energy B. cutting down on the use of fossil fuels C. replacing soil and planting trees D. all of the above

**Science**

100

**algebra**

The half-life of 234U, uranium-234, is 2.52 105 yr. If 98.4% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

**Geometry**

2. Segment RT is the midsegment of the trapezoid. Find x.

**Chemistry**

Calculate the molar heat of neutralization in kj/mol of the reaction between HA and BOH given the following information: The temperature change equals 9C 50mL of 1M concentration of Acid 50ml of 1M concentration of Base Heat Capacity of the calorimeter is 6.5 J/C. Specific ...

**Chemistry**

Thank you. This helps!

**Chemistry**

What is Qcal?

**Chemistry**

Assume a piece of hot metal is added to a calorimeter containing 50mL of water at 22C. The amount of heat released by the metal was determined to be 1000J, and the equilibrium temperature in the calorimeter was 26C. Remembering that the specific heat of water is 4.18 J/gC, how...

**Chemistry**

Calculate the calorimeter constant if 25g of water at 50C was added to 25g of water at 25C with a resulting temperature of 35C? The answer is 52.3 but I do not know how to get to this. I hope someone can help. Thanks!

**Chemistry**

Assume a piece of hot metal is added to a calorimeter containing 50mL of water at 22C. The amount of heat released by the metal was determined to be 1000J, and the equilibrium temperature in the calorimeter was 26C. Remembering that the specific heat of water is 4.18 J/gC, how...

**Chemistry**

Thank you!

**Chemistry**

Assume the heat absorbed by the calorimeter was 200J. What is the calorimeter constant (Heat Capacity) if the temperature changed from 22C to 26C? I know the answer is 50 J/k. But I am not sure how to get this.

**Chemistry**

For each of the following pairs of elements, state whether the binary compound formed is likely to be ionic or covalent. Give the formula and name of the compound. (a) C, Cl Its covalent, but I get the formula wrong and name wrong,CCl Carbon Chloride.

**Chemistry**

thanks

**Chemistry**

(a) A sample of cesium metal reacted completely with water, evolving 48.7 mL of dry H2 at 24°C and 774 mmHg. What is the equation for the reaction? Include states-of-matter under SATP conditions in your answer. Use the lowest possible coefficients. (b) What was the mass of...

**Chemistry**

A neutral molecule is identified as a tetrafluoride, XF4, where X is an unknown atom. If the molecule has a dipole moment of 0.63 D, can you give some possibilities for the identity of X? (Select all that apply.) sulfur nitrogen oxygen polonium phosphorus selenium tellurium ...

**social studies**

No problem that's why I'm here to help

**social studies**

Changing the command to General Meade, instead of Gen. Hooker, put a responsive and drill instructor commander of the Army of the Potomac. Basically changing command put a better general in Meade leading the union army. Meade's force controlled the high ground which made ...

**Chemistry**

Yeah I was totally confused with this and I could not follow it in the book. This was a annoying problem.

**Chemistry**

The term degeneracy means the number of different quantum states of an atom or molecule having the same energy. For example, the degeneracy of the n = 2 level of the hydrogen atom is 4 (a 2s quantum state, and three different 2p states). What is the degeneracy of the n = 1 level?

**Chemistry**

Thanks Dr. Bob

**Chemistry**

A particular microwave oven delivers 800 watts. (A watt is a unit of power, which is the joules of energy delivered, or used, per second.) If the oven uses microwave radiation of wavelength 12.2 cm, how many photons of this radiation are required to heat 1.25 g of water 1.00&...

**Chemistry**

A sample of cesium metal reacted completely with water, evolving 48.7 mL of dry H2 at 24°C and 774 mmHg. What is the equation for the reaction? (Include states-of-matter under SATP conditions in your answer. Use the lowest possible coefficients.) What was the mass of ...

**Chemistry**

At what speed must an electron travel to have a wavelength of 13.6 pm? I got 9.89x10^-15 m/s as the answer and its wrong where did I mess up in my calculations? I keep coming up with 9.89x10^-15 m/s and its wrong.

**Chemistry**

I put into my calculator (6.626e-34)/(9.109e-31)(0.92e-11)= 6.69e-15 m/s but it is wrong, so what did I mess up?

**Chemistry**

is it V=h/m x wavelength

**Chemistry**

So the solution to the problem is v= wavelength x h/m?

**Chemistry**

At what speed must a neutron travel to have a wavelength of 9.2 pm?

**Chemistry**

ok thanks for your help

**Chemistry**

What is the energy of a photon corresponding to radio waves of frequency 1.475 106 /s? I got 9.77e-28 as an answer and its wrong so what is wrong with my calculations.

**Chemistry**

At what speed must an electron travel to have a wavelength of 13.6 pm? I got 9.89x10^-15 as the answer and its wrong where did I mess up in my calculations?

**Chemistry**

What is the wavelength of the electromagnetic radiation emitted from a hydrogen atom when the electron undergoes the transition n = 5 to n = 3?((Broken Link Removed) is a spectrum m In what region of the spectrum does the line occur? near ultraviolet far ultraviolet near ...

**Chemistry**

Any object, be it a space satellite or a molecule, must attain an initial upward velocity of at least 11.2 km/s in order to escape the gravitational attraction of the earth. What would be the kinetic energy in joules of a satellite weighing 2337 lb that has the speed equal to ...

**Chemistry**

A sample of ethanol, C2H5OH, weighing 2.84 g was burned in an excess of oxygen in a bomb calorimeter. The temperature of the calorimeter rose from 25.00°C to 33.73°C. If the heat capacity of the calorimeter and contents was 9.63 kJ/°C, what is the value of q for ...

**Chemistry**

The specific heat of copper metal was determined by putting a piece of the metal weighing 39.4 g in hot water. The quantity of heat absorbed by the metal was calculated to be 47 J from the temperature drop of the water. What was the specific heat of the metal if the ...

**Chemistry**

(a) A 102-g sample of water is placed in an insulated container and allowed to come to room temperature at 21°C. To heat the water sample to 41°C, how much heat must you add to it? kJ (b) Consider the hypothetical reaction, being run in an insulated container that ...

**Chemistry**

Propane, C3H8, is a common fuel gas. Use the following to calculate the grams of propane you would need to provide 383 kJ of heat. C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g) ΔH = −2043 kJ

**Chemistry**

Suppose you mix 20.1 g of water at 66.2°C with 45.1 g of water at 35.7°C in an insulated cup. What is the maximum temperature of the solution after mixing?

**Chemistry**

When ice at 0°C melts to liquid water at 0°C, it absorbs 0.334 kJ of heat per gram. Suppose the heat needed to melt 30.7 g of ice is absorbed from the water contained in a glass. If this water has a mass of 0.189 kg and a temperature of 21.0°C, what is the final ...

**Chemistry**

How much heat is released when a mixture containing 12.6 g CS2 and 13.2 g Cl2 reacts by the following equation? CS2(g) + 3 Cl2(g) → S2Cl2(g) + CCl4(g) ΔH° = −230. kJ

**Chemistry**

A 19.5-g sample of a metal was heated to 61.67°C. When the metal was placed into 27.1 g of water in a calorimeter, the temperature of the water increased from 25.00°C to 30.00°C. What is the specific heat of the metal?

**Chemistry**

Hydrogen is burned in oxygen to release heat. How many grams of hydrogen gas must be burned to release enough heat to warm a 50.0 g block of iron, giving 5 mol of water? 2 H2(g) + O2(g) → 2 H2O(g) ΔH = −484 kJ Iron has a specific heat of 0.449 J/(g·°...

**Chemistry**

Nitrous oxide, N2O, has been used as a dental anesthetic. Suppose that the average speed of an N2O molecule at 25°C is 377 m/s. (It is actually 379 m/s.) Calculate the kinetic energy (in joules) of an N2O molecule traveling at this speed.

**Chmistry**

Any object, be it a space satellite or a molecule, must attain an initial upward velocity of at least 11.2 km/s in order to escape the gravitational attraction of the earth. What would be the kinetic energy in joules of a satellite weighing 2337 lb that has the speed equal to ...

**CHEMISTRY**

pH=~9.2

**math**

you have16 coins that are heads up an18 coins that are tails up. After you add some coins that are tails up, the ratio of heads up to tails up is 1 to 1.5. How many coins are tails up? How many coins are in all?

**algebra**

Please help with solving this 5r(6rs-12st)t

**chemistry**

Consider the reaction 2Al + 3CuSO4 = Al2(SO4)3 + 3Cu What is the maximum amount of Cu (63.5 g/mol) that could be produced by reacting 20.0 grams of Al (27.0 g/mol) with excess How do i do this?

**college**

A 26 loudspeaker is suspended 3.0 below the ceiling by two cables that are each 40 from vertical. What is the tension in the cables? help please!

**Physics**

A banked circular highway curve is designed for traffic moving at 60 km/h. The radius of the curve is 207 m. Traffic is moving along the highway at 42 km/h on a rainy day. What is the minimum coefficient of friction between tires and road that will allow cars to take the turn ...

**math**

find the unknown number in equation 9s=17+1

**Anatomy**

another name and cause of hyperthyroidism

**physics 101**

explain rocket propulsion in terms of conservation of momentum

**Finance**

Thank you Reiny.

**Finance**

How much cash must be deposited in a savings account In Order To Accumulate 50,000 At End Of 7 Years With 12 % Interest Rate?

**finance**

solve for x 10000 = 2500(1.0425)^3 + X(1.0425)^2 + 3500(1.0425)^

**Finance**

what is the present value of annuity of $950 per year for 18 years ( with the first payment to be made today and the last payment to be made 17 years from today) give an interest rate of 7.5% p.a?

**Finance**

Solve for x. 10000 = 2500(1.0425)^3 + X(1.0425)^2 + 3500(1.0425)^1

**algebra**

x + 2y = 4 and x - 4y = 8, solve for x

**Finance**

A firm has ROA of 14% and a debt/equity ratio of 0.8. The ffirms ROE is?

**Finance help**

Assume Williams inc has: Debt ratio= 40% Net profit margin= 10% Return on assets = 25% Find williams Total Asste Turnover Ratio

**World History**

Taoism: advocating a simple honest life and noninterference with the course of natural events.it is philosophical system developed by Lao-tzu and Chuang-tzu as-well

**PHYSICS**

A 745i BMW car can brake to a stop in a distance of 122 ft from a speed of 60.0 mi/h. To brake to a stop from a speed of 80.0 mi/h requires a stopping distance of 221 ft. What is the average braking acceleration for the following intervals? Express the answers in mi/h/s and in...

**math**

And if f(x)=1/2 and g (x)=x-2 how do i calculate: F-1 (4)

**math**

is this done correctly?? given that f(x) and g(x)=x-2 calculate a)g(-2)=-2-2=-4 b)fg(4)=1/2 *4=2

**Physics**

To stop a car, first you require a certain reaction time to begin braking. Then the car slows down at a constant rate. Suppose that the total distance moved by your car during these two phases is 56.7 m when its initial speed is 85.0 km/h, and 24.4 m when the initial speed is ...

**Biology**

If you mean things in our everyday life this will help: http://en.wikipedia.org/wiki/Economic_importance_of_bacteria

**Physics continuation - Damon please help**

There is not enough information, was there a previous question or other info?

**CHEM**

The answer is 3

**History**

What was the function of the egyptian funerary complex?

**science**

That is a magnetic field.