# Posts by mark

Total # Posts: 1,630

**Chemistry**

In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and enthanol are "burned" to water vapor andCO2. Write a combustion reaction for ethanol. I need help with balancing the equation i think ...

**Chemistry**

In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of respiration(...

**Chemistry**

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of respiration(combustion...

**Chemistry**

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of respiration(combustion...

**physics**

An astronaut on the Moon throws a stone from the top of a cliff. The stone hits the ground below 21.0 seconds later. The acceleration due to gravity on the moon is 1.6 ms–2. what is the initial vertical velocity?

**Chemistry**

i think it's C2H6OH(l) + 3O2(g) ---> 2CO2(g) + 3H2O(g)

**Chemistry**

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of respiration(combustion...

**chemistry**

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of respiration(combustion...

**chemistry**

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of respiration(combustion...

**chemistry**

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of respiration(combustion...

**Chemistry**

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of respiration(combustion...

**algebra**

a triangle has coordinates A(1,2),B(4,-2), and C(1,1) graph the triangle.

**Science**

Which of Earth sprees contain most of the mass?

**Math**

10 x 3 + 7 - 4 x 3 =30 + 7 - 12 =37 - 12 =25

**Maths ( urgent help )**

But I didn't get what the question says. 21 days from the beginning..... ??

**Maths ( urgent help )**

thank you very much sirr.

**Maths ( urgent help )**

20 men can do a piece of work in 24 days. After working for 6 days, an additional number of men are taken to finish the work in 21 days from the beginning. Find the number of additional men . . . I tried using variation method but the answer didn't come correct :(

**Biology**

Can you answer mine its on your last question?

**Math**

Please help me with my midterm review my teacher was out sick today and idk how much longer she will be but my midterms Thursday. She only helps people who she has seen done there midterm review and gotten over half of it right so can any of you please help me. Write the first...

**Finance**

Templeton Extended Care Facilities, Inc. is considering the acquisition of a chain of cemeteries for $400 million. Since the primary asset of this business is real estate, Templeton's management has determined that they will be able to borrow the majority of the money ...

**Chemistry**

A 1.50 g sample of glucose (C6H12O6) is burned in a bomb calorimeter that contains water at 25.0 0C. The heat capacity of the bomb calorimeter is 1046 J/0C. When the glucose is combusted, the temperature of the water rises to 47.4 0C. Calculate the heat of combustion of ...

**Chemistry**

rank the gases Ar, N2,CH4, and C2H6 in order of the increasing density at STP answer: CH4<N2<C2H6<Ar please help me solve this

**Chemistry**

Consider the generic reaction: 2 A(g)+ B(g)--> 2C(g). If a flask initially contains 1.0 atm of A and 1.0 atm of B, what will be the pressure in the flask if the reaction proceeds to completion? (Assume constant volume and temperature.) answer is 1.5atm how do you solve this

**Chemistry!!!!!!!!**

A sample of Xe takes 75 seconds to effuse out of a container. An unknown gas takes 37 seconds to effuse out of the identical container under identical conditions. What is the most likely identity of the uknown gas the answer is O2. How do you solve this?

**Chemistry**

which gas has the greatest kinetic energy at STP? a)He b)Ne c)Ar d) None of the above(All have the same kinetic energy) how do I solve for this?

**Chemistry**

A gas sample at STP contains 1.15 oxygen and 1.55g nitrogen. What is the volume of the gas sample? the answer 2.04. I want to know how to get the that answer

**Chemistry**

which gas sample has the greatest volume at STP? a)10.0g Ar b)10.0g Kr c) 10.0 g Xe d) none of the above (They all have the same number)

**Chemistry**

A 255mL gas sample contains argon and nitrogen at a temperature of 65 degrees celsius. The total pressure of the sample is 725mmHg and the partial pressure of argon is 231 mmHg. what mass of nitrogen is present in the sample?

**Chemistry**

A gas mixture in a 1.55L at 298K container contains 10.0g Ne and 10.0g Ar. Calculate the partial pressure " in atm" of Ne and Ar in the container

**Physics**

A skier launches off a ski jump with a horizontal velocity of 25.3 m/s (and no vertical velocity component). a) What is the magnitude of the horizontal component of her velocity the instant before she lands 1.95 s later? b) What is the magnitude of the vertical component of ...

**science**

A heat engine draws 800J of heat from its high temperature source and discards 450J of exhaust heat into its cold temperature reservoir during each cycle.How much work does this engine perform per cycle?

**biology**

why did dinosaurs evolve earlier than humans?

**Math**

A 13.5 gallon tank is 4/5 full. How many gallons will it take to fill the tank.

**science(bio)**

Why did dinosaurs evolve so much earlier than humans?

**Chemistry**

15.00mL sample of a solution of H2SO4 of unknown concentration was titrated with 0.3200 N NaOH. The titration required 21.30mL of the base. What was the normality of the acid solution? what was the molarity of the acid solution?

**math**

what is 3.9370007 in scientific notation thanks

**FIN/370**

18%

**chemsitry**

The weak acid HQ has pKa of 4.89. Calculate the [H3O+] of .035 M HQ. Thanks.

**Chem**

Why should a dilute NaOH solution be used for the standardization of NaOH in the analysis of Aspirin using back titration?

**english composition**

Biosocial science is a new area of science that has developed from recent discoveries. These discoveries include new information about the nature versus nurture debate, cultural determination, and genetic and behavioral tendencies. Researchers hope this new area of study will ...

**Chemistry**

for each of the following acid-base reactions calculate the mass (in grams) of each acid necessary to completely react with and neutralize 4.85g of the base solution 1)2HNO3(aq)+ Ca(OH)2 (aq)> 2h20(l)+ Ca(NO3)2 2) H2SO4(aq)+ 2KOH(aq)---> 2H2O(l)+ K2SO4

**English**

Hey my teacher is out sick and you did our midterm review a while back. Can you please give me the answers if it wouldn't be to much trouble for you. Write the first four terms of the sequence whose general term is given. an = 3n - 1 Answer 2, 3, 4, 5 2, 5, 8, 11 -2, -5, -...

**Math**

A stick 60 cm long is cut into two pieces in yhe ration 2:3 how long is each P.s I need it on September 23 4:00 am plssssssss thank you

**Algebra**

So what's b the answer to the question?

**Math**

you have a piece of wood that is 144 inches long. you cut it into three pieces. the second piece is 12 inches longer than the first piece. the third piece is 12 inches longer than the second piece. write and solve the equation to find the lengths of the three pieces

**math**

A normal distribution has a mean of 44 and a standard deviation of 4. What is the probability that a value drawn from the distribution lies between 36 and 48? A) 0.18 B) 0.32 C) 0.82 D) 0.91

**Trigonometry**

a boat travels on a course of bearing n 37 10' W for 79.5 miles. How many miles north and how many miles west has the boat traveled?

**Trigonometry**

Prove sin theta ( sec theta+ csc theta)= tan theta+1

**Chemistry**

A 78.9g sample of HCN contains 0.290g of H and 4.06g of N. Find the mass of carbon in a sample of HCN with a mass of 3.37 g

**Physics**

A particle with a mass of 0.660 kg is attached to a horizontal spring with a force constant of 23.76 N/m. At the moment t = 0, the particle has its maximum speed of 15 m/s and is moving to the left. (Assume that the positive direction is to the right.) (a) Determine the ...

**Physics**

The position of a particle is given by the expression x = 2.00 cos (6.00πt + π), where x is in meters and t is in seconds. (a) Determine the frequency. ______Hz (b) Determine period of the motion. ______s (c) Determine the amplitude of the motion. ______m (d) ...

**Algebra**

If a bottle and a cork cost $2.00, and the bottle is $1.00 more than the cork, what is the cost of each?

**GT**

A GAS EXPANDS IN VOLUME FROM 26.7 ML TO 89.3 ML AT CONSTANTTEMPERATURE. CALCULATE THE WORK DONE (IN JOULES) IF THE GASEXPANDS (A) AGAINST A VACUUM,(B) AGAINST A CONSTANT PRESSUREOF 1.5 ATM, AND (C) AGAINST A CONSTANT PRESSURE OF 2.8 ATM.

**Physics**

A 2.50 kg fireworks shell is fired straight up from a mortar intending to reach 110m. How much downward force is created to propel that shell upwards to it's intended target?

**Physics**

Calculate the initial velocity for each using the average time of fligh up, the acceleration of gravity and the initial velocity. The average time up for A is 3.18s and for B is 1.87s and using the formula t=Vo Sin(theta)/g. Please and thank you!!!

**Physics**

Calculate the initial velocity for each using the average time of fligh up, the acceleration of gravity and the initial velocity. The average time up for A is 3.18s and for B is 1.87s and using the formula t=Vo Sin(theta)/g. Please and thank you!!!

**Geometry**

The base of a right prism is a rhombus with a side of 10 cm and an altitude of 9.6 cm. Find the diagonals of the prism if the altitude of the prism is 12 cm.

**Physics**

The speed of a projectile when it reaches its maximum height is 0.42 times its speed when it is at half its maximum height. What is the initial projection angle of the projectile?

**biogloy**

A rock to a snail

**Physics**

thanks

**Physics**

Could you specify the 120/200? is it just Delta(t)= 120/200 ? i want to set it up right.

**Physics**

would it be ~ Delta(y)= 1/2(9.8m/s^2)(.6s)^2 = 1.764 so it would be about 5 feet off? That's quite a miss..

**Physics**

A pistol is fired horizontally toward a target 120 m away but at the same height. The bullet's velocity is 200 m/s. How long does it take the bullet to get to the target? How far below the target does the bullet hit? please explain why you used the formula and how you got ...

**Chemistry**

What are some of the distinctive properties of gases with respect to: density, volume, shape?

**Physics**

A stone is shot upward with a speed of 24.4 m/s from a tower and lands at the base of the tower with a speed of 44.0 m/s. How long does it take?

**US History**

What were the original goals and purposes of the containment policy in 1946? How did the policy change its meaning over time?

**Science--HELP!!**

Ionic bond is printed twice by mistake. Chemical bond is correct.

**Chemistry**

Will 1 L of 1 M NaCl contain more chloride ions than 0.5 L of 1 M MgCl2 explain. One liter of 1 M NaCl contains________ mole(s) of NaCl, therefore_______ mole(s) of chloride ions. 0.5 L of 1 M MgCl2 contains__________ mole(s) of MgCl2, therefore_________ mole(s) of chloride ions.

**Chemistry**

(a) How many grams of KNO3 are needed to make 430 mL of a solution that is to contain 2.9 mg/mL of potassium ion?

**Physics**

Wow, Thanks Damon. Got it!

**Physics**

thanks Damon. I can't seem to figure out where to go next. Substitution seems like the obvious choice, but I don't know which sum to begin with.

**Physics**

Vector C has a magnitude 25.8 m and is in the direction of the negative y-axis. Vectors A and B are at angles α = 41.9° and β = 25.2° up from the x-axis respectively. If the vector sum A B C = 0, what are the magnitudes of A and B?

**geometry**

How did you solve it?

**geometry**

One endpoint of a line segment is (8, −1). The point (5, −2) is one-third of the way from that endpoint to the other endpoint. Find the other endpoint.

**geometry**

Name a point that is between 50 and 60 units away from (7,-2) and state the distance between the two points.

**geometry**

find the equation of the line that describes all points equidistant from the points (1, 2) and (4, 5).

**college geometry**

A rectangle ABCD has three of its vertices at A(2, 1), B(6, 1), and C(6, 3). Find the fourth vertex D and the area of rectangle ABCD.

**college geometry**

M(2.1, 5.7) is the midpoint of , in which A is the point (1.7, 2.3). Find the coordinates of B.

**college geometry**

Points A and B have symmetry with respect to point C. Find the coordinates of C given the points: a) A(3, 4) and B(5, 1) c) A(5, 3) and B(2, 1) b) A(0, 2) and B(0, 6) d) A(2a, 0) and B(0, 2b)

**college geometry**

Points A and B have symmetry with respect to the origin O. Find the coordinates of B if A is the point: a) (3, 4) c) (a, 0) b) (0, 2) d) (b, c)

**college geometry**

Points A and B have symmetry with respect to the origin O. Find the coordinates of B if A is the point: a) (3, 4) c) (a, 0) b) (0, 2) d) (b, c)

**college geometry**

10. Find the midpoint of the line segment that joins each pair of points: a) (Ϫ3, Ϫ7) and (2, 5) c) (Ϫa, Ϫb) and (a, b) b) (0, 0) and (Ϫ2, 6) d) (2a, 2b) and (2c, 2d)

**college geometry**

If the distance between (b, 3) and (7, 3) is 3.5 units, find all possible values of b.

**college chemistry**

How many calories are required to change 259 g of ice at 0 °C to steam at 100 °C?

**Chemistry**

Mount McKinley in Alaska is the tallest peak in North America with a summit at 20,320 ft, or 6194 m. It is also known as Denali, meaning "the high one" in the native Koyukon Athabaskan language. The average atmospheric pressure at the top of Denali is approximately ...

**Chemistry**

If 125 g of ice at 0.0°C is added to 1.95 L of water at 90 °C, what is the final temperature of the mixture?

**Chemistry**

How many joules of energy are needed to change 114 g of water at 16.5°C to steam at 100°C?

**Chemistry**

Upon heating 134 g MgSO4 · 7 H2O: (a) how many grams of water can be obtained? (b) how many grams of anhydrous compound can be obtained?

**math**

thank you,Ms.Sue

**math**

will it be set up like 3 x 21 x 3 =189

**math**

you can get 3 toppings with 1 cheese and 1 crust

**math**

how many pizza choices can you get with 3 crusts,7 toppings and 3 cheeses

**Physics**

I can't figure out how to do this. design an experiment you could construct that might measure the amount of work it takes to change the volume of a gas in a piston. What materials would you use? What would you measure? What results would you expect? What if the results ...

**Chemistry (Acids and Bases)**

Okay thank you. I didn't realize they were the same. But in "What is the pH of a 0.300 molar NaOH solution?" -log(.3)=.523 is incorrect. Why?

**Chemistry (Acids and Bases)**

What is the pH of a 0.400 molar HCl solution? I did -log(.4)=.398. That seems too low. I think I need to find the molarity (M) of the solution, but I can't find it with the given information.

**Science**

There are 2 high and 2 low tides each day. Why do this many tides occur each day?

**chemistry**

A 32.5 g sample of K2SO4 is dissolved in a quantity of water and stirred well. A 40.00 mL sample of the solution is evaporated to dryness and leaves behind 5.00 g of solid K2SO4.what is the molarity. Calculate molar masses of solutes to .01 grams

**math**

3ft

**math**

Five friends shared 2 packs of paper equally. What fraction of a pack of paper did each friend get? I think 2/5

**math**

Some functions that aren't invertible can be made invertible by restricting their domains. For example, the function x^2 is invertible if we restrict x to the interval [0,\inf), or to any subset of that interval. In that case, the inverse function is-\sqrt x. (We could ...