Thursday

July 31, 2014

July 31, 2014

Total # Posts: 56

**Chemistry**

If a solution containing 118.44 g of mercury(II) perchlorate is allowed to react completely with a solution containing 17.796 g of sodium sulfide, how many grams of solid precipitate will be formed? How many grams of the reactant in excess will remain after the reaction?

**Chemistry**

I'm so confused...how do I use the coefficients to balance the equations?

**Chemistry**

In the following reaction, 451.4 g of lead reacts with excess oxygen forming 313.6 g of lead(II) oxide. Calculate the percent yield of the reaction. 2Pb(s)+O2(g)= 2PbO(s)

**Chemistry**

Balance the redox reaction: Ag(aq)+Cu(s)= Ag(s)+Cu(aq)

**Chemistry**

For the following chemical reaction, what mass of silver nitrate in grams will be needed to produce 3.91 mol of calcium nitrate? CaI2+2AgNO3=2AgI+Ca(NO3)2

**Math**

25. Edith earns an annual gross salary of $17,500. She has 28% of her gross salary withheld for taxes and other deductions. What is the net pay of each paycheck if she is paid weekly? $274.04 $43.87 $242.31 26. Franklin deposited $1,400 in a savings account that accrues simple...

**physics**

a: 9.8 t: 2.6 v: 2.11 d: ? d=vt+1/2at d=(2.11)(2.6)+2(9.8)(2.6) d=ANSWER

**science**

D: density M: mass V: volume D=M/V therefore, the density is 64/16=4

**algebra**

Solve -3(5x+6)=57

**algebra**

Solve -3(5x+6)=57

**statistics-math**

The mean score on a Math exam was 50% and the standard deviation was 10%. Assume the results were normally distributed. (a) What percent of students earned a score between 50% and 70%? ( /2)

**physics**

A block of wood is placed in a cup of water. The block has the following dimensions: L=10cm W=5cm H=4cm. If the block is 75% submerged, how much water has been displaced?

**Science 7**

One ohm is the resistance value through which one volt will maintain a current of one ampere.

**Chemistry**

Flask a contains 2 liters of ch4 (g) and flask b contains 2 liters of 02 (g) each gas sample has the same 1) density 2) mass 3) number of molecules 4) number of atoms

**math**

1/2, 4/8, 5/10 (all you have 2 do is multiply or divide both the numerator and denominator by the same # and you get your equivalent fractions.

**chemistry**

how many grams of oxygen are in 560g of ribose?

**Math**

Im in advanced math and were doing Graphing Inequalities and im not sure how to do it.

**physics**

How would you find the coefficient of kinetic friction if you're given a weight of 627 N and theta=45 degrees?

**social studies**

Type this into Wikipedia: European colonization of the Americas

**math**

All you have to do is divide both sides by -5. You will get -1/7 because when you divide the right side by -5, the 5's cancel out to leave you with -1 on top. Let me know if you have more questions.

**math**

Like this: 5/8 * 7/2 So, you multiply the two top numbers (5*7) and the two bottom numbers (8*2) to get the final answer for a.

**math**

1,2,and 3 are right. 4. You need to multiply each side by the opposite. So to cancel out 2/7 on the left side, multiply by 7/2 to get a by itself. Then you have to multiply the right side by 7/2 also. Multiply 5*7 to get the top and 2*8 to get the bottom. Let me know if you ne...

**4th grade**

What exactly is the question?

**substitution method**

Okay so on the first side you have 3 which needs to be distributed to both the 31 and the -6y. On the left side you will end up with 93-18y+8y=33. Now you have to finish solving for y. Add 8y to -18y then subtract 93 from both sides. I think you can take it from here. Let me k...

**math**

This is very simple. All you have to do is put what is equal to x in the second equation (31-6y) in for the x in the first equation giving you the equation 3(31-6y)+8y=33 Solve for the y with this equation then plug that answer into either of the equations to get x. Let me kno...

**Algebra PLEASE HELP**

2r-5s=-12 5r+2s=57 2r-5s=-12 +5s=+5s 2r=5s-12 /2=/2 r=(5/2)s-6 Now that you know r, plug that into the other equation and solve for s. Once you know s, you can plug s into either equation to get r.

**Algebra PLEASE HELP**

You need to solve for one variable in one equation first. The easier one would probably be the first equation. Solve for r by adding 5s to both sides (which cancels 5s on the left side) then divide everything by 2. Plug that answer in for r in the second equation. Let me know ...

**Chemistry**

Radiation in the ultraviolet region of the electromagnetic spectrum is quite energetic. It is this radiation that causes dyes to fade and your skin to develop a sunburn. If you are bombarded with 1.00 mol of photons with a wavelength of 288 nm, what amount of energy, in kilojo...

**Chemistry**

Suppose you are standing 201 m from a radio transmitter. What is your distance from the transmitter in terms of the number of wavelengths for the following conditions? (a) The station is broadcasting at 1150 kHz (on the AM radio band)? (1 kHz = 1 multiplied by 103 Hz.) ?? wave...

**Chemistry**

Sulfur (3.26 g) is burned in a constant volume calorimeter with excess O2(g). The temperature increases from 21.25°C to 28.22°C. The bomb has a heat capacity of 923 J/K, and the calorimeter contains 815 g of water. Calculate ΔU per mole of SO2 formed, for the foll...

**Chemistry**

When 112 g of water at a temperature of 22.5°C is mixed with 65.1 g of water at an unknown temperature, the final temperature of the resulting mixture is 46.3°C. What was the initial temperature of the second sample of water?

**Chemistry**

What volume of 0.105 M HNO3, in milliliters, is required to react completely with 1.40 g of Ba(OH)2? 2 HNO3(aq) + Ba(OH)2(s) Ba(NO3)2(aq) + 2 H2O(l)

**Chemistry**

In an experiment 1.015 g of a metal carbonate, containing an unknown metal M, is heated to give the metal oxide and 0.361 g CO2. MCO3(s) + heat MO(s) + CO2(g) What is the identity of the metal M?

**math**

5 people times 4 tickets each=20 tickets 20 tickets/100 tickets total=1/5 chance or 20% chance

**Algebra 2**

The first one you would move x to the other side making it negative, or subtract x from both sides giving: y=-x+4 -1 is the m and 4 is the b For the second one, you do the same thing. Add 4x to each side canceling the 4x on the left, or move 4x to the other side making it posi...

**Chemistry**

A mixture of CuSO4 and CuSO4·5 H2O has a mass of 1.235 g. After heating to drive off all the water, the mass is only 0.830 g. What is the mass percent of CuSO4·5 H2O in the mixture?

**Physics**

What is the period of the minute hand of a clock?

**College Physics**

A CD has to rotate under the readout-laser with a constant linear velocity of 1.25 m/s. If the laser is at a position 3.2 cm from the center of the disk, what are the revolutions per minute (rpms) of the disk?

**Chemistry**

1. Engineers design air bags that deploy almost instantly upon impact. To do this, an air bag must provide a large amount of gas in a very short time. Many manufacturers use sodium azide, NaN3, to produce the gas in such a manner 2NaN3(s) 2Na(s) + 3N2(g) What volume ...

**Chemistry**

For each of the following, write a net ionic equation (modeled above). Wherever there is a precipitate, state the name of the precipitate (e.g “lead iodide” from above). Pop onto the net and see if you can find a description of the physical properties (e.g colour) o...

**Physics/ optics**

An object is located 25cm in front of a +6.00 lens, where is the image? is it real or virtual?

**optics**

An objuect is located 20cm in front of a -3.00 lens where is the image?

**Pre-Calculus**

After leaving an airport, a plane flies for 1.75h at a speed of 200km/h on a course of 100 degrees. The plane then flies for 2 hours at a speed of 250km/h on a course of 40 degrees. At this time, how far from the airport is the planee?

**maths**

thanks

**maths**

if (x + 3)(x -2) = 1 show that x^2 + x -7 = 0

**math**

Convert 3214five to base ten

**math**

Dorthy is 6 years older than Ricardo. The product of their present age is twice what the product of their ages was 6 years ago. How old is Dorthy?

**6th grade vocab**

What does the word "predominant" mean? Oh and please don't give me a website with some big def. I am in 6th grade so I won't understand if the def. is big and long. It also helps if you use it in a sentence . . . just saying. :-D Thanks so much!

**French**

Thanks Senora for your help with the baby animals. I have a few more, which I tried googling/translating, but I found nothing. giraffe jars Thanks for your help

**French**

Does anyone know a list of baby animals in French, or know specifically what these are? ~baby bunny ~baby "Sanglier" ~baby "vache" ~baby turkey ~baby "Cane" ~baby cerf ~baby "jars" ~baby "jument" Merci for your help

**6th grade**

How do you turn a fraction into a decimal?

**geometry!! urgent (math)**

The lateral edges of a regular hexagonal pyramid are all 20 cm long, and the base edges are all 16 cm long. To the nearest cc, whta is the volume of this pyramid? To the nearest square cm, what is the combined area of the base and six lateral faces?

**math**

x=1

**algebra**

System of equations, the addition method 3x-3y=6 3x+3y=0 Whats the answer?

**math riddle ALGEBRA WITH PIZZAZZ**

Did you hear about.... it has to do something with a rooster or a cow..=s

**Algebra(check pt 2)**

Questions 1 and 2 are correct. I'm not sure about 3 and 4.

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