Saturday
October 1, 2016

Posts by mark

Total # Posts: 1,556

Chemistry
C7H6O3 + C4H6O3 → C9H8O4 + C2H4O2 If you start with 2.09 grams of C4H6O3 how many grams aspirin (C9H8O4) can you make?
December 2, 2015

CHEMISTRY URGENT HELP
How to draw line graph for showing changes in test tubes while showing that exhaled air contains more carbon dioxide than inhaled air
November 28, 2015

Math
What is the circumference of d=2.1cm using 22/7
November 26, 2015

Science
The town of Seaside needs to build a new power plant. The old coal burning plant produces too much pollution and is no longer safe. The mayor decides that he will do some research on alternative forms of energy like nuclear power plants and solar power plants. What types of ...
November 25, 2015

Chemistry
For which element is the gaining of an electron most exothermic? a)Li b)N c)F d)B *explain
November 22, 2015

Science
Please someone help me figure this one out with three reasons. A group of researchers from a local lab are trying to get funding for a research study to determine if the color blue is better than the color green. They have written a proposal and submitted to the company that ...
November 20, 2015

chemistry
2C2H2+5O2(arrow to right) 4CO2+2H2O choices the reaction can be classified as a hydration reaction C2H2 is the oxidizing agent CO2 is the reducing agent carbon is oxidized
November 17, 2015

chemistry
41. Ethyne, C2H2, used in welding react with oxygen as shown below.
November 17, 2015

chemistry
i am working on a practice worksheet and need help with a few i can not understand. please and thank you. I have to post them separately sorry 49.how many grams of water are needed to completely hydrolyze 30.8 g of the ester? A.0.416 g B.30.8 g C.11.3 g D.7.49 g 54. Sodium ...
November 17, 2015

Chemistry
Which molecule contains a polar covalent bond? a)C2H4 b)ZnS c)LiI d)NBr3 e)AgI
November 15, 2015

Philoophy
Definition of Philosophy?? And Definition of logic ??
November 15, 2015

calculus
Use the Left and Right Riemann Sums with 100 rectangle to estimate the (signed) area under the curve of y=−2x+1 on the interval [0,50]. Write your answer using the sigma notation.
November 13, 2015

Calculus
Use the Left and Right Riemann Sums with 80 rectangle to estimate the (signed) area under the curve of y=e^(3x)−5 on the interval of [10,20]. Write your answer using the sigma notation
November 13, 2015

Calculus
Find the points on the curve y=x2+2 closest to the point (0,3). Enter the coordinate with the smallest x-value first and round to the nearest 4 decimal places.
November 5, 2015

programming ( qbasic)
thanks steve sir
November 5, 2015

programming ( qbasic)
rem prints fibonacci series cls a=2 b=1 for p = 1 to 5 print a print b a=a + b b=b + a next p end I have done this program. How do you do it using modular programming.. FUNCTION...END FUNCTION???? I tried but it didnt work
November 5, 2015

programming ( qbasic)
thank you very much
November 3, 2015

programming ( qbasic)
i was given this program by my teacher. it converts decimal number to binary number.. Why is that FIX kept in front of (n/2) ...6th line of the program. why is that FIX written and why? i didnt get it CLS INPUT “ENTER A NUMBER”; N WHILE N <> 0 A = N MOD 2 B$ = ...
November 3, 2015

Physics
A stone is thrown vertically upward with a speed of 21.0 m/s a)How fast is it moving when it reaches a height of 15.8 m b)How much time is required to reach this height?
October 31, 2015

Chemistry
Sulfur dioxide SO2 is released in the combustion of coal. Scrubbers use aqueous slurries of Ca(OH)2 to remove the sulfur dioxide from the flue gases. Write a balanced equation for this reaction and calculate delta So at 298 K (So for CaSO3(s) = 101.4 J/{mol*K}). include the ...
October 29, 2015

chemistry BOB
is this the answer to B ) CH3CH2OH + 3O2 → 2CO2 + 3H2O In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and ethanol are "burned" to water vapor andCO2. Write a combustion reaction ...
October 27, 2015

chemistry
is this the answer to B ) CH3CH2OH + 3O2 → 2CO2 + 3H2O In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and ethanol are "burned" to water vapor andCO2. Write a combustion reaction ...
October 27, 2015

chemistry
help!!!! is this the answer to B ) C2H5OH(liq)+ 3O2(g) --> 2CO2(g) +3H2O(liq) In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and ethanol are "burned" to water vapor andCO2. Write a ...
October 27, 2015

chemistry DR BOB
is this the answer to B ) C2H5OH(liq)+ 3O2(g) --> 2CO2(g) +3H2O(liq) In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and ethanol are "burned" to water vapor andCO2. Write a combustion ...
October 27, 2015

chemistry DR BOB!
is this the answer to B ) C2H5OH(liq)+ 3O2(g) --> 2CO2(g) +3H2O(liq) In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and ethanol are "burned" to water vapor andCO2. Write a combustion ...
October 27, 2015

chemistry Dr BOB
is this right? C2H6O + 3O2 = 2CO2 + 3H2O 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 ...
October 27, 2015

Chemistry Dr. BOB
I don't get it!! 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 ...
October 27, 2015

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 ...
October 26, 2015

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 ...
October 26, 2015

chemistry help!
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 ...
October 26, 2015

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 ...
October 26, 2015

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 ...
October 26, 2015

chemistry help!!!
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 ...
October 25, 2015

chemistry help!!!
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 ...
October 25, 2015

Chemistry
the distance from the sun to earth is 1.496 x10 ^8 km. how long does it take light to travel from the sun to earth How do you solve this?
October 25, 2015

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 ...
October 25, 2015

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 ...
October 25, 2015

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 ...
October 24, 2015

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(...
October 24, 2015

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...
October 24, 2015

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...
October 24, 2015

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?
October 24, 2015

Chemistry
i think it's C2H6OH(l) + 3O2(g) ---> 2CO2(g) + 3H2O(g)
October 24, 2015

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...
October 24, 2015

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...
October 23, 2015

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...
October 23, 2015

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...
October 23, 2015

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...
October 23, 2015

Science
Which of Earth sprees contain most of the mass?
October 22, 2015

Math
10 x 3 + 7 - 4 x 3 =30 + 7 - 12 =37 - 12 =25
October 21, 2015

Maths ( urgent help )
But I didn't get what the question says. 21 days from the beginning..... ??
October 21, 2015

Maths ( urgent help )
thank you very much sirr.
October 21, 2015

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 didnt come correct :(
October 21, 2015

Biology
Can you answer mine its on your last question?
October 20, 2015

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...
October 20, 2015

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 ...
October 19, 2015

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 ...
October 18, 2015

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
October 18, 2015

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
October 18, 2015

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?
October 18, 2015

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?
October 18, 2015

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
October 18, 2015

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)
October 17, 2015

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?
October 17, 2015

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
October 17, 2015

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 ...
October 16, 2015

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?
October 14, 2015

biology
why did dinosaurs evolve earlier than humans?
October 9, 2015

Math
A 13.5 gallon tank is 4/5 full. How many gallons will it take to fill the tank.
October 8, 2015

science(bio)
Why did dinosaurs evolve so much earlier than humans?
October 8, 2015

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?
October 5, 2015

math
what is 3.9370007 in scientific notation thanks
October 5, 2015

FIN/370
18%
October 3, 2015

chemsitry
The weak acid HQ has pKa of 4.89. Calculate the [H3O+] of .035 M HQ. Thanks.
October 2, 2015

Chem
Why should a dilute NaOH solution be used for the standardization of NaOH in the analysis of Aspirin using back titration?
September 29, 2015

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 ...
September 26, 2015

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
September 22, 2015

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, -...
September 22, 2015

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
September 22, 2015

Algebra
So what's b the answer to the question?
September 17, 2015

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
September 15, 2015

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
September 14, 2015

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?
September 11, 2015

Trigonometry
Prove sin theta ( sec theta+ csc theta)= tan theta+1
September 7, 2015

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
September 6, 2015

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 ...
August 5, 2015

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) ...
August 5, 2015

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?
July 22, 2015

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.
July 20, 2015

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?
July 6, 2015

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!!!
June 28, 2015

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!!!
June 28, 2015

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.
June 24, 2015

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?
June 24, 2015

biogloy
A rock to a snail
June 11, 2015

Physics
thanks
June 9, 2015

Physics
Could you specify the 120/200? is it just Delta(t)= 120/200 ? i want to set it up right.
June 9, 2015

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..
June 9, 2015

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 ...
June 9, 2015

Chemistry
What are some of the distinctive properties of gases with respect to: density, volume, shape?
June 7, 2015

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