# vivian

Popular questions and responses by vivian-
## chem

Ka=1.8x10^-5. How do you calculate the value of pKa?

*asked on November 9, 2010* -
## Maths

A right pyramid on a base 4cm square has a slant edge of 6cm.calculate the volume of the pyramid

*asked on October 26, 2011* -
## Chemistry

During recrystallization, an orange solution of a compound in hot alcohol was treated with activated carbon and then filtered through fluted paper. On cooling, the filtrate gave gray crystals, although the compound was reported to be colorless. Explain why

*asked on September 28, 2014* -
## Chemistry

Which of the following solutions will have a higher boiling point? A. 1m C6H12O6 B. 1m NaCl C. 1m MgCl2 D. 1m AlCl3 And pls explain why it is. Thank you so much!!

*asked on February 9, 2012* -
## business

A petty cash fund of $100 is replenished when the fund contains $3 in cash and receipts for $93. The entry to replenish the fund would debit Cash Over and Short for $4. credit Miscellaneous Revenue for $4. credit Cash Over and Short for $4. debit

*asked on October 26, 2010* -
## organic chemistry--please help me!!!

Give equations to show how sulfuric acid can convert 4-methylcyclohexene into a mixture of four isomeric c7H12 compounds(including starting material). Predict the relative amounts of each isomer.

*asked on October 31, 2011* -
## Math

If each edge of a cube is increased by 2 inches, the A. volume is increased by 8 cubic inches B. area of each face is increased by 4 square inches C. diagonal of each face is increased by 2 inches D. sum of the edges is increased by 24 inches is the answer

*asked on August 9, 2018* -
## Biology

Natural selection is an example of a mechanism of evolution. Does this mechanism produce a change in individuals or populations? Explain!

*asked on April 18, 2018* -
## Hypothesis - Statistics

At one school, the average amount of time that tenth-graders spend watching television each week is 18.4 hours. The principal introduces a campaign to encourage the students to watch less television. One year later, the principal wants to perform a

*asked on July 28, 2012* -
## chemistry

2 solutions of equal amounts in a u-tube are separated by a semipermeable membrane. The level os the (more/less( concentrated will rise. I think the answer is (more) but I'm not sure. What do you think?

*asked on February 9, 2012* -
## chemistry

What would be the pH of a 0.563 M solution of ammonia (NH3) at room temperature? The Kb of ammonia is 1.78 × 10−5. 1. 2.5 2. 7 3. 9 4. 4.5 5. 11.5 ( I did this problem but apparently 4.5 isnt the answer)

*asked on May 13, 2011* -
## Algebra

A box contains 5 yellow balls, 3 blue, and 1 red ball. Two balls are drawn at random. Find the probability that the two balls are yellow

*asked on May 22, 2016* -
## Further maths

Two functions f and g are defined over the set of R of real numbers as follows: f:x=2x-3 g:x=xsquare+5 find f[g(x-1)]

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

A ceiling fan draws a current of 0.625 A and has a voltage of 120 V. The resistance of the ceiling fan, to the nearest tenth?

*asked on November 16, 2016* -
## physics

Four copper wires of equal length are connected in series. Their cross-sectional areas are 0.96 cm^2, 2.02 cm^2, 2.90 cm^2, and 5.06 cm^2. A potential difference of 116 V is applied across the combination. Determine the voltage across the 2.02 cm^2 wire.

*asked on May 25, 2016* -
## gravimetric

in the gravimetric determination of barium in BaCrO4, what weight of sample must be taken so that the weight of the precipitate in milligrams multiplied by 100 will equal the % Ba in the sample?

*asked on April 20, 2015* -
## gravimetric prob

A pure organic compound weighing 947.4mg was heated in a stream of oxygen. The effluent gas was swept successively through a tube of magnesium perchlorate dessicant weighing 18.6137g and a tube of Ascarite weighing 16.8425g. After several minutes the tubes

*asked on April 20, 2015* -
## Maths

Calculate the volume and curved surface area of a cone 14cm in base diameter and 24cm high

*asked on October 26, 2011* -
## History

What creatures did the europeans introduce in the new world?

*asked on February 17, 2011* -
## business

Internal controls are concerned with?

*asked on October 26, 2010* -
## Limits

Lim (tan^2(x)/x) x->0

*asked on August 29, 2010* -
## chemistry

What is the volume of 2.0M H2SO4 (aq) that would neutralize 25 mL of 4.0M NaOH (aq)?

*asked on June 6, 2020* -
## English

Anyone know the answer to this about Romeo and Juliet Act 4? I read through the script and couldn't find Friar Lawrence talking about his plan for Romeo and Juliet after she wakes up besides them going to Mantua, but that's not an answer option. Friar

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

Tau ,Igo,Iron shared a bag of mangoes in the ratio 7:5:14 If Igo receives 18 mangoes less than Iro,how many mangoes does Iro receive?

*asked on June 13, 2019* -
## Math

A scientist travels straight down for 90 seconds at a speed of 3.5 feet per second and then travels directly up for 30 seconds at a speed at a speed of 2.2 feet per second after this 120 second period,how much time in seconds,will it take for the scientist

*asked on April 23, 2019* -
## Business finance

anthony has decided to purchase a $19000 car. he plans to put 20% down toward the purchase and to finance the rest at a 6.8% interest rate for 4 years. find the monthly payment

*asked on May 23, 2017* -
## francis

if the 8th term of an A.P is twice the 5th term, find the 12th term

*asked on April 18, 2017* -
## Chemistry

True or False? An identical cylinder filled with the same pressure of hydrogen contains more molecules because hydrogen molecules are smaller than oxygen molecules.

*asked on January 23, 2017* -
## Chemistry

To clarify, a triple bond between carbon and oxygen is more stable than a triple bond between carbon and nitrogen because oxygen is more electronegative. Is my understanding correct?

*asked on September 30, 2016* -
## Adv. Func./Science Question

Hi, I have this question that I will be tested on but my teacher didn't teach us how to do it so I am confused on how to even start. Please explain on how to start the question...thank you How bright a star appears can depend on how much light the star

*asked on December 12, 2015* -
## physics

A ball is thrown horizontally at 15 m/s from a clifftop 60 m above the sea level. Find: a) the time to land; b) the angle at which it hits the water; ° below the horizontal c) the speed at which it hits the water. m/s

*asked on September 28, 2014* -
## math

in an album, the ratio of the number of local stamps to the number of foreign stamps was 7 : 4. When Lucy gave away 8 local stamps and 8 foreign stamps, there were 1.8 as many local stamps as foreign stamps in the album. find the total number of stamps

*asked on March 5, 2014* -
## math

A government survey conducted to estimate the mean price of houses in a metropolitan area is designed to have a margin of error of $10,000. Pilot studies suggest that the population standard deviation is $70,000. Estimate the minimum sample size needed to

*asked on July 15, 2012* -
## programming in c++

a program in c++ that accepts exam marks for 10 students and stores them in an array.the program should then calculate and utput the average marks for the class.and give an account of marks below average and output all marks above average.

*asked on June 19, 2012* -
## chemistry

A mixture of 16 g of salt and 47 g of baking soda is poured into 296 ml of water. What is the total mass of the mixture in grams?

*asked on June 14, 2012* -
## math

explain how to compare 0.34 and 0.27

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

what are examples of enzymatic disorders? How do the diseases involve enzymatic reactions?

*asked on April 6, 2011* -
## math

s=1/2(a-b)x find b

*asked on January 9, 2011* -
## social studies

What did the Spanish hope to do in California?

*asked on November 30, 2010* -
## Calculus

Lim (tan^2(x)/x) x->0

*asked on August 29, 2010* -
## Physics

Two points in the xy plane have Cartesian coordinates (2.00, -4.00) m and (-5.00, 5.00) m. (a)What is the distance between these two points? (b) What are their polar coordinates?

*asked on January 13, 2010* -
## bio

In heart sound contain of two sound "Lub" and "Dub" When one of these sounds is not distinct, but is more of a gurgle, a person is said to have a heart murmur. What could cause this?

*asked on July 24, 2008* -
## organic chem

Please help! It's one of the prelab questions. **Exp. Ethanol from Sucrose The diethylacetal of acetaldehyde can be detected by gas chromatography. How does this impurity arise in fermentation? **Exp. Acetaminophen In the reaction between p-aminophenol and

*asked on March 17, 2008* -
## Physics

A man drove his car north west for a distance of 10km,then east for 40km and then south for 60km.Calculate the overall displacement and direction of the car from the starting point.

*asked on February 20, 2020* -
## Writing

letter to my uncle telling him to asist me for my school fees

*asked on January 30, 2020* -
## physics

Y=2sin2Π{0.10t-0.1x}

*asked on October 12, 2019* -
## English

“You are running the risk of affairs.” Does this mean that I will be the one who has an affair or is it my partner? I think it is the former one.

*asked on August 19, 2019* -
## English

“Must be paid the day of” means “must be paid on that day,” correct?

*asked on August 2, 2019* -
## Math

Harry mixed 1.3 liters of Grape juice, 2.3 liters of ginger ale and 1.7 liters of orange juice for punch. About how many liters of punch did Harry make?

*asked on May 24, 2019* -
## math

Find all the x-intercepts of the curve y=4x^4-17x^2-15

*asked on August 12, 2018* -
## PHYSICS

A spring 20bn long is stretched to25cm by load of 50N.what will be its length when stretched by 100N,assuming elastic li

*asked on June 5, 2018* -
## math

the sum of two numbers is 60. their difference is 6. construct a system of equations and algebraically find the value of the smaller number.

*asked on January 30, 2018* -
## Sociology

Discuss the inside and remote circumstances that led to the emergence of sociology as a distinct field of study.

*asked on January 24, 2018* -
## Math

Don't understand how to solve this problem: 12. A, B, C, and D are points on a line, and the lengths of the line segments are: AB = 12, BC = 4, CD = 7, and DA = 15. Which of the following is a possible order for the points? A.A,B,C,D B. A,C,D,B C. A,D,C,B

*asked on January 13, 2018* -
## Optimization

Determine the values of the constants α and β so that the function f (x) = x3 + αx2 + βx + δ may have a relative maximum at x = −3, and a relative minimum at x = 1.

*asked on November 2, 2017* -
## Grammer

Combine these 2 sentences with an adverbial clause: The mountain was breathtaking. We took a picture of it.

*asked on May 26, 2017* -
## Government

Which of the following countries is NOT a member of the G-7? Germany France Italy Great Britain Spain

*asked on May 10, 2017* -
## Grammar

Replace with vs. Replace for? 1. Replace white rice with brown rice. Does this mean use brown rice instead? 2. Replace white rice for brown rice. Does this mean use white rice instead?

*asked on March 29, 2017* -
## Chemistry (Ochem)

I know that there is such thing as inversion of stereochemistry,but is there such thing as inversion of stereocenter? Are stereocenter and stereochemistry the same thing or mean the same thing? Thank you, Vivian

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

Hi! So I need help describing someone with heterochromia, for a third-point-of-view fictional story. Thanks for your help!

*asked on February 22, 2017* -
## accounting

Given the cost of direct materials of $500 and the labour rate of $20 per hour. Assuming the predetermined overhead rate is $5 per hour and the actual hours is 50 hours - please calculate the total cost of this job?

*asked on February 20, 2017* -
## Chemistry

Why was sublimation performed under reduced pressure?

*asked on February 5, 2017* -
## Chemistry

1. An empty balloon weighs 10.0 g and is filled to a volume of 20.0 L with CO gas. If the density of air at 25.0 °C and 1.00 atm is 1.17 g/L, will the balloon float? 2. Determine the volume of gas produced at 20.0 °C and 1.00 atm from the complete

*asked on January 26, 2017* -
## Math

I am still confused! Equation: C1V1=C2V2 Given: C1= 15 mM V1=? C2= 0.25 mM V2= 1mL (Do I just plug 1mL into the equation or do I have to convert to liter? Does mM mean mmol/1L?) I got ~17 microliter. Note: I must convert my answer to microliter. Math -

*asked on January 15, 2017* -
## Math

Equation: C1V1=C2V2 Given: C1= 15 mM V1=? C2= 0.25 mM V2= 1mL (Do I just plug 1mL into the equation or do I have to convert to liter? Does mM mean mmol/1L?) I got ~17 microliter. Note: I must convert my answer to microliter.

*asked on January 14, 2017* -
## Math

Calculate the amount of fluorescein (MW 332.31) you will need to make 10 mL of 15 mM solution in ethanol (EtOH). My answer:0.05 g 2.Using Equation C1V1=C2V2 calculate the volume of stock solution (15 mM) you need to make 1 mL of each working solution

*asked on January 14, 2017* -
## Math

1. Calculate the amount of fluorescein (MW 332.31) you will need to make 10 mL of 15 mM solution in ethanol (EtOH). My answer:0.05 g 2.Using Equation C1V1=C2V2 calculate the volume of stock solution (15 mM) you need to make 1 mL of each working solution

*asked on January 14, 2017* -
## Math

If it is 4:00 p.m. then what time is 17 hours ago? Is it 11:00 pm?

*asked on January 5, 2017* -
## Math

A 9.2 ounce can of tomato juice costs $3.48. What is the price per ounce of the tomato juice to the nearest cent?

*asked on November 8, 2016* -
## Grammar

Which is correct? I think the second one is correct. 1. Thank you John, Peter, Susan, and Veronica to be a part of the crew. OR 2. Thank you John, Peter, Susan, and Veronica for being a part of the crew.

*asked on September 23, 2016* -
## Algebra

Write each series as a summation in sigma notation. (−1)^2+0^2+1^2+2^2+3^2

*asked on May 15, 2016* -
## Algebra

Write each series as a summation in sigma notation. 5+8+11+14 i=1

*asked on May 15, 2016* -
## Algebra

Give the list of elements and write in the form with condition the following sets: the set of natural numbers that are multiples of 3

*asked on April 3, 2016* -
## gravimertic prob

an organic pesticide (mw 183.7) is 8.43% cl. a 0.627g sample containing the pesticide plus inert material containing no chloride was decomposed with metallic sodium in alcohol. the liberated chloride ion was precipitated as agcl weighing 0.0831g. calculate

*asked on April 26, 2015* -
## gravimetric prob

A sample of freshly precipitated silver chloride weighs 704.7mg. Before the solution can be filtered and washed 10.0mg of AgCl is photodecomposed. After the precipitate is filtered and washed another 10.0 mg of AgCl is photodecomposed. Calculate the weight

*asked on April 20, 2015* -
## Phsyics HELP!

A car accelerates uniformly from +10.0 m/s to +50.0 m/s over a distance of 225 m. How long did it take to go that distance? Show all your work, including the equation used, given and unknown quantities, and any algebra required. Make sure your answer has

*asked on March 5, 2015* -
## Physics

A plane traveling at 200.0 km/h attempts to land on a 250 m runway. The plane’s engines and brakes accelerate uniformly at –7.0 m/s2. Will the plane be able to land safely? Show all your work. Include any equations used, including the given and the

*asked on March 5, 2015* -
## math

In Carl's drawer, he has white,gray,and black socks. In his closet,he has black brown,and blue shoes. I need to make a diagrdiagram to display the sample space for Carl choosing a sock and shoe color. Is this right White/black,brown blue

*asked on January 21, 2015* -
## physics

a man steps out of a rowboat into a dock. The man has a mass of 80 kg and moves forward with a velocity of 1.5 m/s. If the boat has a mass of 120 kg. and was initially at rest, what is its final velocity?

*asked on November 26, 2014* -
## Chemistry

Construct a cycle with the following steps: Begin with: 1 mol ideal monatomic gas at 300 K and 1 bar. Point A. 1. Isothermal reversible expansion till volume gets twice its original value. Point B. then, 2. Irreversible adiabatic expansion against

*asked on October 6, 2014* -
## Physics

A ball is thrown at 41° below the horizontal from a rooftop of height 65 m. It lands 2 s later. Find: Find: a) its initial speed b) the point of impact with the ground; m from the base of the building c) the angle at which it hits the ground. ° below the

*asked on September 28, 2014* -
## Physics

An electron in an atom has a speed of 2.2 × 10^6 m/s and orbits the nucleus at a distance of 5 × 10^-11m.a)What is its centripetal acceleration? b)A neutron star of radius 17 km is found to rotate at 5 revolutions per second. What is the centripetal

*asked on September 28, 2014* -
## math

What is the smallest six digit number you can make that would round to 126000?

*asked on September 4, 2014* -
## soc 313

ella miller and her family issues

*asked on May 19, 2014* -
## Math

lee and his family are planning a hiking trip on the Appalachian trail. they are packing food in 2lb bundles. how many bundles can they make with 36 lb of food? write a number sentence to help you solve this problem.

*asked on May 20, 2013* -
## college algebra

i need help with elimination and substitution linear equation

*asked on May 5, 2013* -
## Science (chemistry)

Pls help.. Q: prepare a table of value for acid-base titration using 26.40cm^3 as end point

*asked on March 15, 2013* -
## Chemistry

Two liquids A and B have vapor pressures of 71.3 and 131 mmHg, respectively, at 25 degrees Celsius. What is the total vapor pressure of the ideal solution made up in the following concentrations? 1.00 mole of A and 1.00 mole of B 2.00 moles of A and 5.00

*asked on December 7, 2012* -
## Algebra

if a ball standing on four legs wetght 1,200 pounds,how much will this bull weigh when standing on three legs

*asked on August 23, 2012* -
## math

A researcher wishes to estimate the proportion of college students who cheat on exams. A poll of 490 college students showed that 33% of them had, or intended to, cheat on examinations. Find the margin of error for the 95% confidence interval.

*asked on July 15, 2012* -
## Geometry

If the two lines are perpendicular, what is x + y 2y- 10 2x+1

*asked on May 22, 2012* -
## chemistry

Calculate the theoretical pH when 5.00 ml of 0.0100 M HCl is added to 30.00 mL of deionized water.

*asked on April 29, 2012* -
## math

Mia is stacking copies of a new book in a square-pyramid display by the front window of her bookstore. for each consecutive layer, she places one book where four meet. A. I the bottom row of the display has 144 books and there is one book on the top,

*asked on March 14, 2012* -
## Calculus 2

how do we know if the curve theta = pi/2 is a circle, or semicircle, or spiral? I've tried to change the curve to x and y, but both sides of the equation are the same, and tan(pi/2)=infinity.

*asked on February 28, 2012* -
## Calculus

∫[(x+3)/(x^2 +9)]=????? Can you give me a hint for solving it?

*asked on February 8, 2012* -
## chemistry

The freezing-point depression is -0.930 Celsius degree. Determine the molality of the solution of an unknown nonelectrolyte in water. Please help!! I do not understand this problem!

*asked on February 7, 2012* -
## arithmetic

The first three terms in an arithmetic are given by x,4x+5 and 10x-5.find the value of x.

*asked on January 21, 2012* -
## organic chemistry --please help me!!!!!!!!!!!!!!!

Calculate the theoretical yield for the bromination of bothstilbenes and cinnamic acid, assuming the presence of excesspyridinium tribromide. cinnamic acid - 150 mg cis-stilbene - 100 μL trans- stilbene - 100 mg pyridinium tribromide - 200-385 mg

*asked on October 20, 2011* -
## organic chem

How do injector temperature and detector temperature affect retention time of a compound in gas chromatography?

*asked on October 7, 2011* -
## organic chem

An unknown compound melted at 131-133°C. It is thought to be one of the following compounds(mp,°C): trans-cinnamic acid (133-134); benzamide(128-130); DL-malic acid(131-133); or benzoin(135-137). The mixture melting points of the unknown compound with

*asked on September 8, 2011*

## Pages

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