# Mark

Popular questions and responses by Mark-
## 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

*asked on October 18, 2015* -
## chem

In a solution prepared by mixing CH3OH with H2O the major species pesent are 1. a. CH3+, OH, and H2O 2. b. CH3O, H+, and H2O 3. c. CH3OH and H2O 4. d. CH3OH, H+, and OH I know i have to get an equation having trouble doing that!! please help!!

*asked on April 24, 2010* -
## Statistics

A survey of 250 lobster fisherman found that they catch an average of 32 pounds of lobster per day with a standard deviation of four pounds. If a random sample of 30 lobster fisherman is selected, what is the probability that their average catch is less

*asked on May 7, 2014* -
## calculus

at a given instant the legs of a right triangle are 5cm and 12 cm long. if the short leg is increasing at the rate of 1cm/sec and the long leg is decreasing at the rate of 2cm/sce, how fast is the area changing

*asked on December 4, 2008* -
## Chemistry

rank the gases Ar, N2,CH4, and C2H6 in order of the increasing density at STP answer: CH4

*asked on 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?

*asked on October 18, 2015* -
## Physics

An aerialist on a high platform holds onto a trapeze attached to a support by an 8.0-m cord. (See the drawing.) Just before he jumps off the platform, the cord makes an angle of 41° with the vertical. He jumps, swings down, then back up, releasing the

*asked on May 29, 2012* -
## 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?

*asked on October 18, 2015* -
## Physics

A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is its acceleration? A. 0.21 B. 0.46 C. 0.64 D. 0.78 E. 0.97 acceleration= change in velocity/change in time and the velocity= change in displacement

*asked on July 16, 2008* -
## 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.

*asked on May 31, 2015* -
## physics

A storage tank at stp contains 18.5kg of nitrogen. What is the volume of the tank and what would the pressure be if you added another 15kg of nitrogen at the same temperature?

*asked on April 19, 2011* -
## Statistics

Two cards are drawn in succession from a deck without replacement. What is the probability that both cards are greater than 2 and less than 8?

*asked on May 3, 2017* -
## 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?

*asked on June 2, 2015* -
## chemistry

A voltaic cell is contructed in which a copper wire is placed in a 1.0 M Cu(NO3)2 solution and a strip of gold i placed in a 1.0 M AuNO3 solution. The measured potential of the cell is found to be 1.36V and the copper electrode is negative. The Ered for

*asked on July 17, 2010* -
## Trigonometry

two airplanes leave an airport at the same time one hour later they are 189km/hr apart. if one plane traveled 168km/hr and the other traveled 244km/hr for the hour what is the angle between their flight path

*asked on June 8, 2016* -
## Chemistry

What are the concentrations of OH– and H in a 0.00070 M solution of Ba(OH)2 at 25 °C? Assume complete dissociation.

*asked on October 20, 2011* -
## physics

A cube of ice is take from the freezer at -8.5C and placed in a 95g calorimeter aluminum cup containing 310g of water at 20degC. The final situation is observed to be all water at 17degC. What was the mass of the ice cube?

*asked on April 24, 2011* -
## Algebra

Solve the polynomial equation by finding all real roots x^4+15x^2-16 Many thanks

*asked on February 21, 2020* -
## 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?

*asked on May 26, 2015* -
## Math

LongLast Inc. produces car batteries. The mean life of these batteries is 60 months. The distribution of the battery life closely follows the normal probability distribution with a standard deviation of 8 months. As part of its testing program, LongLast

*asked on April 25, 2014* -
## 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

*asked on October 18, 2015* -
## Physics

A 20-cm-diameter cylinder that is 40 cm long contains 50 g of oxygen gas at 20C. What is the number density of the oxygen? in m^-3 What is the reading of a pressure gauge attached to the tank? in kPa

*asked on April 25, 2012* -
## Trig/Pre-Calc

A bird is flying 30 mph in a direction 30 degrees south of east. Affecting the flight of the bird is a wind blowing from the northeast to the southwest at a speed of 10 mph. What is the resulting speed of the bird?

*asked on April 21, 2017* -
## 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?

*asked on October 14, 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

*asked on June 9, 2015* -
## math

The sum of my ones and tens digit is 10. My tens digit is greater than my ones digit. I am a prime number. What number am I?

*asked on September 8, 2009* -
## Physics

A car is traveling on a level horizontal rode comes to a bridge during a storm and finds the bridge washed out. The driver must get to the other side, so he decides to try leaping it with his car. The side of the road the car is on 21.3m above the river,

*asked on March 22, 2017* -
## chemistry

41. Ethyne, C2H2, used in welding react with oxygen as shown below.

*asked on November 17, 2015* -
## Physics

A raindrop (mass 1.00 g) is travelling at a speed of 40m/s when it hits the surface of 100 g of water contained in a drinking glass. What is the change in temperature of the water in the glass if we assume that a) all the kinetic energy of the raindrop is

*asked on April 7, 2011* -
## US History

According to Black Elk, what atrocities took place at Wounded Knee? How did President Harrison describe these atrocities? Whom did Black Elk blame for the Wounded Knee Massacre? Whom did Harrison blame? According to President Harrison, what was the future

*asked on March 30, 2016* -
## Statistics

Reginald Brown an inspector from the department of weights and measures, weighs 15 eighteen-ounce cereal boxes of corn flakes. he finds their mean weight to be 17.78 ounces with a standard deviation of .4 ounces. are the cereal boxes lighter than they

*asked on May 4, 2014* -
## electronic

A 1mm cross section of copper wire is isolated. The charge that flows through the cross section is Q t = 4t^2 + 5 How much current flows through the wire in 6 seconds?

*asked on July 4, 2018* -
## Chemistry

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

*asked on November 22, 2015* -
## Chemistry

Which molecule contains a polar covalent bond? a)C2H4 b)ZnS c)LiI d)NBr3 e)AgI

*asked on November 15, 2015* -
## English-tenses

Hello I have key answers for the following tasks but I would like a native speaker to explain to me the uses of tenses here.The students have to put past tenses here. I am especially confused with the sentence beginning with The vases, which.... isn't it a

*asked on November 25, 2011* -
## Chem

Balance the chemical equation given below, and determine the number of grams of MgO needed to produce 15.0 g of Fe2O3. _MgO(s)+_Fe(s)->_Fe2O3(s)+_Mg(s) 1. a. 11.4 g 2. b. 3.78 g 3. c. 1.26 g 4. d. 0.0877 g I got equation balanced 3,2,1,3 just having

*asked on April 24, 2010* -
## algebra

Solve the problem. Helen Weller invested $15,000 in an account that pays 12% simple interest. How much additional money must be invested in an account that pays 15% simple interest so that the total interest is equal to the interest on the two investments

*asked on March 8, 2009* -
## Math

Find the diameter and the height of a cylinder of maximum volume which can cut from a sphere of radius 12cm

*asked on April 30, 2019* -
## PHYSICS! HELIUM BALLON

Under standard conditions, the density of air is 1.293 kg/m3 and that of helium is 0.178 kg/m3. A spherical helium balloon lifts a basket plus cargo of mass 277.0 kg. What must be the minimum diameter of the spherical balloon?

*asked on April 25, 2016* -
## 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

*asked on November 17, 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)

*asked on October 17, 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

*asked on September 22, 2015* -
## statistics

John Davis, a manager of a supermarket, wants to estimate the proportion of customers that will be using food stamps at his store. How large a sample is required to estimate the true proportion to within 3% with 98% confidence?

*asked on May 4, 2014* -
## Math

A carpenter has several boards of equal length. He cuts 3/5 of each board. After cutting the boards the carpenter notices that he has enough pieces left over to make up the same length as 4 of the original boards. How many boards did the carpenter start

*asked on January 27, 2014* -
## Math

The sides of the triangle at right are formed by the graphs of 3x+ 2y = 1, y = x − 2, and −4x+ 9y = 22. Is the triangle isosceles? How do you know?

*asked on February 12, 2013* -
## Math

Jane has only $1 and $5 in her wallet, and they total $79.00. If she has a total of 23 bills, how many of each bill does she have?

*asked on July 27, 2011* -
## physics

A 88g arrow is shot from a bow whose string exerts an average force of 110n on the arrow over a distance of 78cm.What is the speed of the arrow as it leaves the string?

*asked on March 14, 2011* -
## Chem

When 0.10 g of insulin is dissolved in 0.200 L of water, the osmotic pressure is 2.30 Torr at 20°C. What is the molar mass of insulin? I tried using the van't hoff equation, converting Torr into atm; but not sure how to do it. my teacher didn't really

*asked on February 15, 2010* -
## Statistics

Applying what you have learned.... When politicians make claims that we need to spend a large amount of money to achieve a goal, the claim is often made without legitimate evidence to support a claim that a given program will have a particular result.

*asked on May 22, 2020* -
## 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.

*asked on June 24, 2015* -
## Algebra

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

*asked on March 26, 2015* -
## Statistics

Health issues due to being overweight affect all age groups. of children and adolescents 6-11 years of age,18.8% are found to be overweight. A school district randomly sampled 130 in this age group and found that 20 were considered overweight. at Alpha

*asked on April 27, 2014* -
## Psychology

Phyllis is anxious to ride the parachute drop at the park. Her friend, Betsy, feels faint at the thought and does not enjoy watching others ride. These different reactions demonstrate that _______________. A. perception of stress varies among individuals

*asked on July 26, 2013* -
## Math (Algebra)

A jar contains x nickels and y quarters only. What percentage of the total number of coins are quarters?

*asked on April 3, 2013* -
## finance

1. The U.S. ﬁnancial system is composed of: (1) policy makers, (2) a monetary system, (3) ﬁnancial institutions, and (4) ﬁnancial markets. Indicate which of these components is associated with each of the following roles: a. accumulate and

*asked on January 19, 2013* -
## marketing

Binomial probability distributions are used in business, science, engineering, and other fields. Suppose you work for a marketing agency and have to create a television ad for Brand A toothpaste. The toothpaste manufacturer claims that 40% of the

*asked on September 27, 2012* -
## Astronomy/Physics

I'd love thorough solutions to these problems, but simply providing the specific formulas that I should solve each part of the problem with would be really good too. :-) Thanks! Human energetics You are sitting down to study in the library. Let’s find

*asked on March 4, 2009* -
## algebra

Solve the polynomial equation by finding all real roots g(x) = x^4 + 15x^2 -16 SO: (X^2+16) (X-1)....I'M STUCK THANKS

*asked on February 21, 2020* -
## US History

Camp meetings, like the one in the picture above, were thought to inspire which of the following? (picture showing crowds of people gathered around people in a forest) Men and women to give their lives to God ** Men and women to accept and pray for sinners

*asked on April 12, 2018* -
## Calculus

a pebble is dropped into a calm pond, causing ripples in the form of concentric circles. the radius r of the outer ripple is increasing at a constant rate of 1 root per second. When the radius is 4 feet, at what rate is the total area A of a disturbed

*asked on October 10, 2017* -
## Journal entries accounting

journalize the following entries: 1, Received partial payment of $211 from J. Kronsnoble for work billed on June 7. 3. Paid for supplies purchased on June 4. my answers: 1. cash 211 accounts recvieable 211 3. supplies 258 accounts payable 258

*asked on September 20, 2017* -
## Social Studies

1. Which statement best describes nations? A. must follow the laws set by the United Nations. B. Nations have less political power than do regional organizations. C. Nations interact almost exclusively with other nations in their region, D. Nations have

*asked on August 31, 2017* -
## Accounting

A company operates an arcade place where customers put money into game membership cards and they also accumulate points for winning and can be redeemed for prizes. How to account for the credits not yet used and also the points? I would think.... 1) For

*asked on July 2, 2017* -
## Math

Write an equation in the indicated form for each statement described below. (A graph shows two lines intersecting at x=-2 and y= 1 in a tilted X shape) A. Write an equation in slope-intercept form for the line parallel to the red line and going through the

*asked on February 25, 2017* -
## geometry

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

*asked on May 31, 2015* -
## math

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

*asked on May 24, 2015* -
## Geometry

The length of a rectangle is 3x+10 feet and its width is x+12 feet. If the perimeter of the rectangle is 76 feet, how many square feet are in the area of the rectangle?

*asked on March 26, 2015* -
## Science

How many minutes are required for a radio signal to travel for Earth to a space station in Mars if the planet Mars is 7.83 x 10 to the 7th km from Earth?

*asked on March 20, 2014* -
## Psychology

Ralph was the third child born to a family of seven. At times his mother confused his name with those of his five brothers. His was never the tallest, the strongest, the fastest, or the smartest in school. He was also too little to do something or too old

*asked on July 26, 2013* -
## Math

Let ABCDEF be an equiangular hexagon with perimeter 98 such that EF=2CD=4AB and BC=2FA. What is the length of EF?

*asked on July 15, 2013* -
## Physics

A typical laboratory centrifuge rotates at 4100 rpm. Test tubes have to be placed into a centrifuge very carefully because of the very large accelerations. (a) What is the acceleration at the end of a test tube that is 11 cm from the axis of rotation?

*asked on October 7, 2012* -
## science

The lock-and-key model holds that?

*asked on April 26, 2012* -
## BIO

Organisms that live in environments and are hypotonic have cell membranes that differ in permeability from those that live in isotonic environments. What water regulation adaptations might have evolved to allow these organisms to survive in different

*asked on December 19, 2011* -
## English - Native speakers

Need a help from a native speaker of English. Can you fill in this text by using either Past Simple, Past Continuous or Past Perfect? You would really help a lot. Thank you When Craig Myers __________(buy) his restaurant, he got it for a very good price

*asked on December 12, 2011* -
## Chemistry

In a chemical reaction, exactly 2 mol of substance A react to produce exactly 3 mol of substance B 2A ---> 3B How many molecules of substance B are produced when 27.9 g of substance A reacts? the molar mass of substance A is 24.7 g/mol STEP 1: convert the

*asked on January 22, 2011* -
## business

Which pair of accounts follows the rules of debit and credit, in relation to increases and decreases, in the same manner? A. Accounts Payable and Rent Expense B.Repair Expense and Notes Payable C.Prepaid Insurance and Advertising Expense D.Service Revenues

*asked on September 28, 2010* -
## Calculus

maximum and minimum of y = cos(x) + sin (x)on the interval [0,2pi]

*asked on October 25, 2009* -
## chem

How many moles of ethylene glycol must be dissolved in 500 g of water (Kf = 1.86) to lower the freezing point to -5.00 0C?

*asked on February 5, 2008* -
## English

The Odyssey By Homer -- Book 11 What lesson does Odysseus learn about himself? How has it strengthened his resolve to return to Ithaka?

*asked on January 27, 2008* -
## chemistry - kinetics

The activation energy for the isomerization of methyl isonitrile is 160 kJ/mol. Calculate the fraction of methyl isonitrile molecules that have an energy of 160 or greater at 500 K? 510 K? What is the ratio of the fraction at 510K to that at 500K? I missed

*asked on March 6, 2007* -
## Maths

Annie drives between two towns at an average speed of 40 mph. Tariq drives between the same two towns on the same route at an average speed of 25 mph. Annie leaves the first town at 9 am and arrives at the second town at 10:30 am. If Tariq sets off at the

*asked on May 22, 2020* -
## geometry/check my work

For triangle ABC , which transformation composition is Commutative? a) rotate 30 degrees and then translate 2 units down b) translate 5 units to the right and rotate 90 degrees c) reflect across the y-axis and then rotate 90 degrees d) reflect across the y

*asked on April 5, 2017* -
## Algebra

Person A can paint the neighbor's house 2 times as fast as Person B. The year A and B worked together, it took them 5 days. How long would it take each to paint the house? So, i know how to setup the problem, but i'm not sure what steps I need to take to

*asked on April 7, 2016* -
## US History

Discuss the different approaches of the federal government toward the Plains Indians

*asked on March 30, 2016* -
## Math

the question is "Joe rode his bike over a piece of gum. Joe continued riding his bike at a constant rate. At time t=1.25 seconds the gum was at a maximum height above the ground and 1 second later the gum was at a minimum. If the wheel diameter is 68cm

*asked on February 7, 2016* -
## 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.

*asked on November 5, 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

*asked on October 27, 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

*asked on October 18, 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?

*asked on October 5, 2015* -
## 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_________

*asked on June 3, 2015* -
## math

Which one of the following statements is true? If f is continuous on (a, b), then f attains an absolute maximum value and f attains an absolute minimum inside the interval (a, b). If f '(x) > 0 on the interval (a, b), then f is decreasing on the interval

*asked on February 3, 2015* -
## math

The ratio of an object's weight on Earth to its weight on Neptune is 5 : 7. How much would a person who weighs 150 pounds on Earth weigh on Neptune?

*asked on December 3, 2014* -
## Chemistry

Ammonia is produced when Nitrogen gas reacts with Hydrogen gas, as shown by the equation below: N2 + 3H2 --> 2NH3 If the percentage yield is 90%, what would be your experimental yield of NH3 if 145.8g of N2 react? 2) 2Mg + O2 --> 2MgO A) If 50g of Mg

*asked on May 21, 2014* -
## statistics

The average age for licensed drivers in a county is µ= 42.6, σ= 12 and the distribution is approximately normal. A county police officer was interested in whether the average age of those receiving parking tickets in the county differed from that of the

*asked on April 19, 2014* -
## physics

A soccer ball leaves the foot of a player with an intitial velocity of 22 m/s at an angle of 30 degrees above the positive x-axis. What is the initial velocity in the y-direction? Two sigfigs Remember...no units...but it would be in m/s

*asked on September 7, 2012* -
## College Chem

How many molecules of CH3OH will contain 3.20 x 10^23 H atoms?

*asked on July 16, 2012* -
## Chem

A mixture containing 5.0 g of H2 and 10.0g of O 2 is allowed to react in a 15.0L container at a constant temperature of 25.0 C. Once the reaction is complete, what will be the pressure of the excess gas inside the container?

*asked on July 16, 2012* -
## Statistics Question (Confidence Interval)

A sample of 15 recent college graduates found that starting salaries for attorneys in New York City had a mean of $102,342 and a standard deviation of $21,756. Construct a 95% confidence interval for the average starting salary of all attorneys in the

*asked on March 14, 2012* -
## managerial economics

Recently one of the nation’s largest consumer electronics retailers began a nationwide television advertising campaign kicking off its “Take It Home Today” program, which is designed to encourage electronics consumers to buy today rather than

*asked on November 15, 2011* -
## Trig

Solve the equation in the given domain cos 4x + cos 2x = 0, 0

*asked on November 14, 2011*