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Marcus
Questions and answers by visitors named
Marcus
Questions (139)
What mass of water must be used to dissolve 20.0 grams of ethanol, C2H5OH, to prepare a 0.0500 molal solution of ethanol?
10 answers
3,420 views
Solve. I have no digits the same. My thousands digit is less than my tens digit. My hundreds digit is twice my ones digit. If
4 answers
280 views
place the operation signs (+,-,x, divide) in the order that makes each sentence true
18__6__2=15
4 answers
222 views
What is the relationship between shapes and shapes?
1 answer
353 views
The Linear equation y=6x-5 graphs as a horizontal/vertical/diagonal line ( choose the correct label and type it below)
2 answers
1,021 views
The circumference of the base of a cylinder is 16 cm. The height of the cylinder is 10cm.
a. What is the surface area of the
4 answers
1,355 views
How would day and night be different if Earth's axis were not tilted?
3 answers
435 views
Why is Venus hotter than Mercury even though Mercury is closest to the Sun?
3 answers
378 views
�ã[81x12y8z10]
1 answer
203 views
Please calculate the solubility of calcium sulfate in 0.010 mol/L calcium nitrate at SATP.
This very question has been bugging me
2 answers
576 views
Mr.Daly is running short on cash and needs to gas up his car. After filling his car up at the local gas station he takes off
1 answer
386 views
In which situations is it appropriate to display data using circle graphs?
When is it inappropriate to use the data displays in
1 answer
390 views
I don't know what to do.
Hosni fave the following argument that -(a+b)= -a+-b, for all intergers a and b. If the arqument is
4 answers
340 views
I need to know how to do this. In steps
9x^2-3x 4x^2-9
1 answer
360 views
List terms that complete a possible pattern in each of the following.
7,8,15,23,38 ____, ____, _____ I can not figure this out.
6 answers
502 views
How would proportions be used to "scale up" or "scale down" something?
(Not really sure if I even understand what this means. I
1 answer
341 views
A rock is dropped from a sea cliff and the sound of it striking the ocean is heard 6.4 s later. If the speed of sound is 340
4 answers
656 views
How do I know what the simple subject of the sentence is and the complete subject?
3 answers
474 views
Use an appropriate local linear approximation to estimate the value of Cotangent 46 degrees.
3 answers
842 views
Ethanol is a fuel that can be made from corn. How many kJ of heat energy are released when 3.00 kg of ethanol are burned?
C2H5OH(
3 answers
1,194 views
Determine whether the graphs of the equations are parallel lines, perpendicular lines, or neither.
12x + 4y = 16 5y - 22 = -15x
3 answers
1,076 views
Can you rank these from the smallest to the largest?
Heart carbon atom sodium atom electron nucleotide tundra mitochondria
2 answers
526 views
the amount of time spent in North American adults watching television per day is normal distributed with a mean of 6 hours and a
4 answers
485 views
You drive due east at 78 km/h for 55 min. Then you follow a road going 60 degrees south of east, going 99 km/h for another 38
1 answer
397 views
please help!
You are given an unknown, colorless, solution that may contain only one salt from the following set: NaA, NaB, NaC.
3 answers
1,452 views
A 67.0 kg base runner begins his slide into second base when moving at a speed of 3.5 m/s. The coefficient of friction between
3 answers
732 views
Ginny has a pumpkin with a mass of 4.8kilograms. If .9 of its mass is water, how much of its mass is water? How much is not
1 answer
184 views
Given triangleABC is congruent to triangleXYZ, if AB=3X-1, BC=5X+2, XY=7, and YZ=14, find X.
1 answer
383 views
An ideal monatomic gas initially at 298 K and 1 atm pressure is
expanded from a volume of 1 liter to 2 liters. Consider
1 answer
631 views
How many gallons of fossil fuel to make a gallon of each of the following?
synfuel soy ethanol cellulosic electricity
1 answer
471 views
How many hours will it take a bicyclist traveling 17.6 feet per second to finish a 90-mile race? Round your answer, if
1 answer
464 views
If AB=5x+2 and AC=12x-2, what is BC?
1 answer
312 views
You have 10 ml of a 1:10,000 solution of hydrogen peroxide (H2O2). What is the molar concentration of the solution?
1 answer
428 views
DEFG is an isosceles trapezoid. Find the measure of <E.
4 answers
2,738 views
Facebook reports that the average number of Facebook friends worldwide is 175.5 with a standard deviation of 90.57. If you were
2 answers
1,040 views
The linear equation
y=0.15x+0.79 represents an estimate of the average cost of gas for year x starting in 1997. the year 1997
2 answers
573 views
Write a 1,400- to 1,750-word paper on essential communication in a community crisis situation described in the scenario.
Include
6 answers
593 views
A basket containing 80 eggs weighs 2kg 300g. The same basket containing 60 eggs weighs 1kg 700g. Find the mass of the empty
2 answers
944 views
If a painter paints 8 different pictures to get a better perspective and then only selects 1 picture to illustrate her mood:
1 answer
296 views
is 0.14 equal to 0.104
1 answer
308 views
What is the acceleration of a 50kg person is pushed with a force of 4N
1 answer
349 views
A weightlifter has a basal metabolic rate
of 80.0 W. As he is working out, his metabolic rate increases by about 650 W. (a) How
1 answer
941 views
The teacher asked Laura to give each
student 2/5 sheets of paper. If there are 20 students in the class how much paper did Laura
1 answer
449 views
You have 2/3 bag of flour. Use 3/4 of
the flour to make cookie dough. How much of the entire bag do you use to make cookie dough?
6 answers
2,632 views
how do I write equation for the following?
input a 20/28/36/44/52 output b 5/7/9/11/ ? ? is 13
1 answer
302 views
The rate of a reaction A ---> B is expressed by the rate expression rate=k(A)2. If the molar concentration of A is tripled, the
2 answers
776 views
What is the molality of an aqueous solution that is 10.0% ethanol, C2H5OH, by mass?
26 answers
asked by
Marcus
4,157 views
A solution contains 10.0 g pentane, C5H12, 10.0 g hexane, C6H14 and 10.0 g benzene, C6H6. What is the mole fraction of hexane?
I
3 answers
2,411 views
When 1.150 grams of an unknown nonelectrolyte dissolves in 10.0 grams of water, the solution freezes at -2.16°C. What is the
4 answers
3,825 views
What is the vapor pressure of a aqueous solution containing 10 % (by weight) ethylene glycol (62 g/mol) at 25 °C. PH2O = 24.3
5 answers
3,731 views
2A + B2 + C --> A2B + BC
Run # Initial Rate (M-1s-1) (A)o (B)o (C)o 1 1.6 x 106 1.2 M 1. x 10-2 M 1.0 M 2 1.6 x 106 2.4 M 1. x
2 answers
861 views
In a given 1st order reaction A ---> products, the initial concentration of A is 0.40 M. What will be the concentration of A
2 answers
597 views
The decomposition of N2O5(g) --> NO2(g) + NO3(g) proceeds as a first order reaction with a half-life of 30.0 seconds at a
2 answers
1,015 views
Cyclopropane rearranges to form propene:
CH2CH2CH2 --> CH2=CHCH3 by first-order kinetics. The rate constant is k = 2.74 x 10-3
3 answers
1,708 views
In a given 1st order reaction A ---> products, the initial concentration of A is 0.40 M. What will be the concentration of A
3 answers
2,468 views
Which of the following pure liquids is the best solvent for sodium fluoride?
CCl4 C2C6 HCl BCl3 or PCl5 My guess would be either
2 answers
1,339 views
Which of the following solutes in aqueous solution would be expected to exhibit the smallest freezing-point lowering (assuming
4 answers
5,220 views
Which of the following solutes, dissolved in 1000g of water, would provide a solution would the lowest freezing point?
.030 mol
3 answers
1,584 views
The decomposition of ozone may occur through the two-step mechanism shown below:
step 1 O3 ----> O2 + O step 2 O3 + O ---> 2O2
3 answers
1,363 views
Another proposed mechanism problem:
H2O2 + I ---> H2O +IO slow H2O2 + IO ---> H2O + O2 + I fast Which of the following statements
1 answer
711 views
The molal boiling-point constant for water is 0.51 degrees C/molal. The boiling point of a 1.00 molal solution of Ca(NO3)2
3 answers
2,395 views
A sample of propane C3H8 contains 13.5 moles of carbon atoms how many total moles of atoms does the sample contain?
4 answers
5,094 views
A proton is put on the positive Y axis a large distance (100km) from the origin. What is the minimum speed required in the - Y
5 answers
1,037 views
A proton is put on the positive Y axis a large distance (100km) from the origin. What is the minimum speed required in the - Y
4 answers
462 views
Stupid question time. I need to figure out how to rearrange equations to solve for x in my chemistry homework, which involves
1 answer
482 views
Same kind of problem. How to rearrange to put an equation in quadratic form.
Example I'm given is 49.7= 2x^2 / (1.00-x)(2.00-x)
1 answer
425 views
I'm working on a problem dealing with calculating the heat of vaporization for vapor pressures problem.
By substituting the
2 answers
840 views
Domain of g(x)
g(x)= sqrt(3-(sqrt(25-x^2)) I got -5, -4, 4, and 5. I wrote it like [-5, -4] U [4, 5] I don't think that's right?
4 answers
465 views
Is 3.05313131313131313131313131... irrational or rational? Thanks.
3 answers
309 views
solve (x-3)/(x+1) > 5
I get x < -2 every time, but it doesnt work when I plug it back in. (I plugged in -5)
4 answers
285 views
lim as x approaches 3+
x^2+x-6/18-3x-x^2 I factored it into (x+3)(x-2)/(6+x)(3-x)
3 answers
313 views
lim x->1 (1-(1/x^3))/ (1-(1/x^2))
I keep seeming to get a denominator of zero when I rationalized the denominator.
1 answer
379 views
lim x->0+ for 1/1+ (5^(1/x))
I think there's no limit, since there is a vertical tangent at 0, is this correct?
1 answer
298 views
A function is continuous at a point if its limit exists at that point.
I think it's false because of the counterexample of
1 answer
373 views
A function can be continuous at every point of a deleted neighborhood of some point and still not have a limit at the point
2 answers
497 views
When the concentration of a weak acid in solution is equal to the concentration of its conjugate base in solution, then:
Would
1 answer
1,073 views
When looking at a titration curve, I have to determine which is not true and I have it narrowed down to two options:
The initial
1 answer
385 views
What is the [H+] of the 0.25 M HCl solution?
I'm not given a Ka value, so I'm assuming I won't need one to solve this particular
1 answer
341 views
The indicator bromocresol green (HIn) can be in two different forms: As HIn the color of the indicator is yellow, an In the
1 answer
672 views
First, the question I'm given is: What is the pH of a 1.0 L solution containing 0.25M acetic acid and 0.75M sodium acetate ( Ka
1 answer
409 views
What is the pH of a 0.1 M NaOCl solution (Ka of HOCl is 2.95 x10-8)
I did: x squared/.10= 2.95x10-8 x squared= 2.95x10-9 x=
4 answers
2,870 views
The question is: what is the ratio [NH3/[NH4+] in an ammonia/ammonium chloride buffer solution with pH= 10.00? (pKa for
4 answers
2,679 views
Which of the following result in buffered solutions when equal volumes of the two solutions are mixed?
a.) .1 M HCl and .1 M
2 answers
1,331 views
To illustrate the calculation, assume that 21.95 mL of a thiosulfate solution is required to reduce the iodine liberated by
4 answers
578 views
Many portable gas heaters and grills use propane, C3H8(g).
Using enthalpies of formation, calculate the quantity of heat produced
4 answers
1,626 views
Factor:
49^2+112r+64 =
4 answers
315 views
Which sentence uses proper grammar?
I'm bored by math class. Or I'm bored of math class.
5 answers
533 views
Meteorologists track a storm using radar. The radar shows a storm centered 30km west of town. Ninety minutes later, it's 30km
1 answer
436 views
A running track consists of two straight 88.5m segments and two semicircles of radius 39.0m
The distance a runner travels in one
2 answers
588 views
aluminum reacts with sulfuric acid to produce aluminum sulfate and hydrogen gas. how many grams of aluminum sulfate would be
3 answers
1,513 views
At a summer campfire, the radius of a marshmallow on a stick expands at the rate of
\ {r ' (t)} = \frac{2.4 }{3 t + 6} mm/s where
2 answers
542 views
You pull a sled across a horizontal frictionless patch of snow. If your pulling force is in the same direction as the sled's
4 answers
2,901 views
Doris invested some money at 7% and some money at 8%. She did at 7%. Her yearly total from the two investments was $7.80.
How
2 answers
537 views
Four cheeseburgers and five milkshakes cost a total of $25.50. Two milkshakes cost $1.75 more than one cheeseburger, and also
2 answers
528 views
I am sorry I didn't complete the problem
Here is the question: Doris invested some money at 7% and some money at 8%. She invested
2 answers
631 views
Simplify the exponential expression
[-10x13y^12]^0 ---------------- 2x^9y^3
3 answers
386 views
Sodium metal is immersed into graduated cylinder that holds exactly 32.5 ml. The sodium metal used to fill the cylinder weighs
3 answers
578 views
50.0 mL of a solution of HCl is combined with 100.0 mL of 1.15 M NaOH in a calorimeter. The reaction mixture is initially at
4 answers
1,776 views
What are the values (negative) being taught in this advertisement? The advertisement is trying to sell a military style watch.
3 answers
519 views
What are the values (negative) being taught in this advertisement? The advertisement is trying to sell a military style watch.
2 answers
637 views
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