# Posts by John

Total # Posts: 8,337

**Organic Chemistry 2**

What is the purpose of adding NaOH ot the reaction? This is the from our Benzil Lab.

**Organic Chemistry 2**

Isolation of crude Benzoind-allow about 5 minutes for the crystals of benzoin to form fully. place the flask, with crystals, into an ice bath for 5-10 minutes. Break up the crystalline mass with a spatula, swirl the flask rapidly and quickly transfer the benzoin to a hirsch ...

**Organic Chemistry 2**

Procdure. Reaction Mixture-Add 0.3 g of thiamine hydrochloride to a erlenmeyer flask. Dissolve the solid in 0.45 mL of water by swirling the flask. Add 3.0 mL of 95% ethanol, and swirl the solution until it is homogeneous. To this solution add 0.9 mL of an aqueous sodium ...

**Organic Chemistry 2**

umm in this lab, benzoin condensation of benzaldehyde will be carried out with a biological coenzyme, thiamine hydrochloride, as the catalyst:

**Organic Chemistry 2**

What is the impurity that must be removed from the benzaldehyde reagent before it can be used in this experiment? this is from are Benzil lab

**Physics**

The propeller blades of an airplane are 2.4 m long. The plane is getting ready for takeoff, and the propeller starts turning from rest at a constant angular acceleration. The propeller blades go through two revolutions between the fifth and the seventh second of the rotation. ...

**Math**

9/16 x 2/3 =

**math 8th grade**

for a project, you need the diagonal fold of a square piece of origami paper to be 10 cm long. to what dimensions do you need to cut the square origami paper?

**math 8th grade**

a black 8" tile was cut to surround a white 8" tile. what is the perimeter of the design?

**math 8th grade**

what is the height of an equilateral triangle with an edge of one meter?

**calculus**

An Olympic athlete is standing at the edge of one side of a 3.7km wide river and wants to reach the point 7.4km downstream just along the edge of the opposite side. For this entire 7.4km stretch, the river is completely straight. The velocity of the current is negligible. The ...

**Math! Pls Help!**

i need help on that same thing can you put something els up

**Biology**

0.052

**chemistry**

To a 100.0 mL solution containing 0.0100 M Ba(NO3)2 and 0.0100 M Pb(NO3)2 was added 101.0 mL of 0.0100 M H2SO4 to provide a slight excess of SO42- relative to Ba2+ in the resulting solution. Assuming that: i) H+ does not bind to SO42- ii) ionic strength effects can be ignored ...

**Physics**

The propeller blades of an airplane are 2.4 m long. The plane is getting ready for takeoff, and the propeller starts turning from rest at a constant angular acceleration. The propeller blades go through two revolutions between the fifth and the seventh second of the rotation. ...

**Calculus**

For a cylinder with a surface area of 90, what is the maximum volume that it can have? Round your answer to the nearest 4 decimal places. The volume of a cylinder is πr^2*h and the surface area is 2πrh+2πr^2.

**physics**

You drop a 1.90 kg book to a friend who stands on the ground at distance D = 11.8 m below with outstretched hands at distance d = 1.42 m above the ground. a)What is the speed of the book when it reaches the hands? b)If we substituted a second book with twice the mass, what ...

**Algebra 1**

Did you ever find out the answer?

**Math**

a wrench is dropped by a worker at a construction site. four seconds later the worker hears it hit the ground below. How high is the worker above the ground? (The velocity of sound is 1100 ft/s, and the distance the wrench falls as a function of time is s=6t^2

**physics**

a block of mass M = 9.9 kg rests on a bracket of mass m = 5.5 kg. the bracket sits on a frictionless surface. the coefficients of friction between the block and the bracket on which it rests are .4 and .3. what is the maximum force that can be applied if the block is not to ...

**science**

Ana exerts a force of 20 N on a volleyball that has a mass of 0.15 kg. What is the force that the volleyball exerts on Ana?

**biology**

Determine the effective population size of the current population located on an island. You conduct a census and determine there are about 1500. -Your initial survey indicated that there are 500 juveniles (Smaller, with no horns) on the island. What would you consider the ...

**Physical science**

Mist graph

**math**

Ms.Sue can you help me

**math**

@Ms.Sue

**math**

what is 10 5/18 - 8 5/6 A. 2 5/9 B. 2 13/18 C.1 4/9 d. 1 11/18 I think It is B?

**Physics**

When jumping straight down, you can be seriously injured if you land stiff-legged. One way to avoid injury is to bend your knees upon landing to reduce the force of the impact. A 69.3-kg man just before contact with the ground has a speed of 6.94 m/s. (a) In a stiff-legged ...

**maths**

Fence post are placed 3m apart from each other. How many posts will be placed over a distance of 45m?

**business statitics**

a) The mean lifetime of a sample of 100 light tubes produced by a company is found to be 1570 hours with standard deviation of 80 hours. Test the hypothesis that the mean lifetime of the tubes produced by the company is 1600 hrs. (7 marks)

**math**

Find the values of the trigonometric function cot -8/17 sin: sec: tan: cot: I know you use a Pythagorean Identity, sin^2t + cos^2t=1 I got 64/289 for the first one for example and it was wrong.

**Calculus**

A force of 6 pounds is required to hold a spring stretched 0.2 feet beyond its natural length. How much work (in foot-pounds) is done in stretching the spring from its natural length to 0.6 feet beyond its natural length? could you please explain how. thanks

**chem - help!**

Different manufacturers claim to have the best antacid. Which of the following tablets would neutralize the most acid for the money? Write a balanced chemical equation along with your answer. a) Rolaids (550 mg CaCO3 and 110 mg Mg(OH) per tablet) - 150 tablets for $9.44 b) ...

**vectors linear algebra**

The parametric equations for a line L1 are as follows: x = −4−6t y = 2+2t z = 1−4t Let L2 be the line parallel to L1 and passing through the point (−3, −3, −3). Find the point P on L2 whose x-coordinate is −12. P=P(-12, _ , _ ) ?

**math**

find the sum of the sequence 41+42+43+44+117

**chem**

Different manufacturers claim to have the best antacid. Which of the following tablets would neutralize the most acid for the money? Write a balanced chemical equation along with your answer. a) Rolaids (550 mg CaCO3 and 110 mg Mg(OH) per tablet) - 150 tablets for $9.44 b) ...

**physics**

17 23

**biology**

Which of the following statements best explains the relationship between the mitochondria and the plasma membrane? A. The mitochondria makes proteins that become a part of the plasma membrane. B. The mitochondria makes a gas that the plasma membrane uses. C. The mitochondria ...

**science**

im confused are these answers incorrect ?

**math**

6.85 ?

**math**

Suppose f(t) is the weight (in grams) of a solid sitting in a beaker of water and the solid is dissolving at a rate (in grams/minute) of f'(t)=-4 f(t)(3 + f(t) ). If there is 4 grams of solid at time t=2 minutes, use a linear approximation to estimate the solid's ...

**math**

Suppose f(t) is the weight (in grams) of a solid sitting in a beaker of water and the solid is dissolving at a rate (in grams/minute) of f'(t) =-4 f(t)(3 + f(t) ). If there is 4 grams of solid at time t=2 minutes, use a linear approximation to estimate the solid's ...

**math**

Suppose N(t) denotes a population size at time t where the dN/dt=0.03 N(t). If the population size at time t=4 is equal to 100, use a linear approximation to estimate the size of the population at time t=4.1.

**math**

A cup of coffee at 173 degrees is poured into a mug and left in a room at 72 degrees. After 6 minutes, the coffee is 137 degrees. Assuming that Newton's Law of Cooling applies: After how many minutes will the coffee be 100 degrees?

**math**

Suppose f(x)=ln x. (a) Find the linear approximation of f at a=1. L(x)= (b) Use the linear approximation to estimate ln 1.27. ln1.27=

**Chemistry**

Do positive ions or the negative ions cause the change in flame color ? Explain why and give on example.

**Reading: Paricia A. Ackerman**

Gudnite!

**Reading: Paricia A. Ackerman**

Dinner Together : Sitting by the barbecue waiting for sausages and hot dogs blue-gray smoke the same color of the sky I see a tiny spider walking down from the sky with tiny six footed steps down down in a perfectly straight line all the way down to the floor then back up the ...

**Reading: By Houghton Mifflin**

On page 241 Focus on Poetry Animals Dinner Together: sitting by the barbecue waiting for sausages and hot dogs blue-gray smoke the same color of the sky I see a tiny spider walking down the sky with tiny six footed steps down down in a perfectly straight line all the way down ...

**Reading**

Poetry animals dinner together. What is all about? Page 241

**math**

john has 24 baseball cards. chard has 13 more cards than john. draw a comparison problem to illustrate how to solve the problem, then slove

**Math**

3x+3(x-1)<-18

**Marh**

The nearest sq mile would be a whole number, so round to the nearest whole number. (the place for the decimal). I am assuming the value you stated is in square miles.

**Math**

When the problem says "about" it sounds like they are looking for an estimate. A good estimate would be to multiply 6 times 700 to get 4200.

**Counting and Probability**

Any 2-digit number with a 1 is special (and all special numbers have at least one 1). There are nine 2-digit numbers with ones digit 1, and, there are nine additional 2-digit numbers with tens digit 1 (except from 11, which we've already counted, since its ones digits is ...

**Math**

Could the 1.5 miles take him farther because it said across and not around the loop? There might be another 1.5 to add to the total. Not sure...

**maths**

In general, distance = rate x time This case: distance = (rate + current) x time distance = (rate - current) x time 100 = (50 -c)(t) 100 = (50+c) (t + 3 3/4 minutes) This should get you started.

**physcial science**

B moving electric charges cause a magnetic field to form.

**Math**

multiply the 7.5 times 3 to give you 22.5 times 10^-5 To get to standard notation you need to write the 22.5 as 2.25 x 10^1 combine the 1 + -5 to get -4 because we have the same base of 10. When multiplying, you keep the base and add the exponents. 2.25 x 10^-4

**physics**

32 m/sec will be decreased at for 3.0 sec. 32-12 = 20 m/s 4.0 m/sec times 5.25 sec. = 21 m/sec 1m/sec faster. b) d= rt You could use the average rate by computing the beginning and ending speeds

**Geometry**

yes!

**math Help Azap!!!**

To solve for a, we first have to remove the ( ) 9a -3a +18 = -6 6a + 18 = -6 Can you finish from here? Be sure to check your answer in the original equation.

**Algebra**

1) 7(3) = -56(33y) 7(3)/ (-56)(33) = y 2) (8)(44) = (29)(11k) (8)(44)/(29)(11) = k Can you finish from here? You can make the math a little simpler by cancelling.

**Math**

divide both sides by -4 which causes you to flip the sign...you have the sign correct, but it should be a 3 The first choice. Every set is a subset of itself, so it should be the last choice.

**algebra**

It looks like k = -2 because 3x times -2 = -6x and -2 times -2 = 4

**English**

What literary device is being used in this passage? "'See!' he cried triumphantly. 'It's a bona-fide piece of printed matter. It fooled me. This fella's a regular Belasco. It's a triumph. What thoroughness! What realism! Knew when to stop, too--...

**Adamson University Math**

Klasmeyt may sagot ka na dyan? naghahanap din po ako eh.. need help po :)

**geomtry**

two angles form a linear pair the measure of one angle is 24 more than the measure of the the other anglr

**Math**

A lock has 3 tumblers each has 10 numbers from one through zero, how many possibilities to open lock and what are the numbers ?

**Math**

Typo 1/12

**Math**

12 marbles total 3/12 times 3/12 if you are replacing it. 1/4 times 1/4 = 1/16 There are 6 possible outcomes. 1/6 to roll a three and 3/6 to roll an even number. For both to happen you have 1/6 times 1/2

**algebra**

2x + 3y = 1470 Slope intercept form is y = mx+b So you want to solve for y: subtract 2x from both sides and divide by 3. 3y = -2x +1470 y = -2/3 x + 1470/3 or y = -2/3x +490 To graph you would start at the point (0,490) and to find the next point you would use -2/3 = change in...

**Physics**

A golf ball strikes a hard, smooth floor at an angle of 20.7 ° and, as the drawing shows, rebounds at the same angle. The mass of the ball is 0.0528 kg, and its speed is 40.2 m/s just before and after striking the floor. What is the magnitude of the impulse applied to the ...

**Math**

It is -9 sorry about the typo.. I am glad Ms. Sue caught that.

**Math**

Simplify like terms which means to combine the 10h -5h which is 5h 9 + 5h = 0 subtract 9 from both sides 5h = 9 Divide by 5 to get h = 9/5

**Math**

Here is a nice website that shows steps that you asked for in #4 - I am not allowed to post it. Do a google search of solving linear equations and look for one related to NYS regents. If you can solve for the variable, the equation is open. If you eliminate all of the ...

**Math**

projectile hits the ground when s(t) = 0 meaning the height off the ground is zero. 0 = 144t -16 t^2 Factor out the t: 0 = t(144 -16t) set each part = to zero t = 0 the projectile wasn't launched yet and 144- 16t = 0 solve for t to find out how long the projectile was in ...

**physics**

A 56-kg rollerblader skates across a skating rink floor. The graph below shows the net external force component F cos è along the displacement as a function of the magnitude of the displacement d. Determine the Following: (a) work done by the net force component F cos &...

**statistics**

17 balls total There are 10 red 10/17 is your chance.

**math**

For #4, you are subtracting 1 from each part and not adding it. subtracting 1 gives you 2x = 10 and 2x = -12 You had the right idea, but the adding 1 is wrong, you really subtracted 1. Teacher was probably looking for you to show the adding 8 and dividing by 4 and for the ...

**Math**

When you solve the equations, you will find that when the letters (variables) are eliminated you will be left with a number on each side of the equal sign. If they numbers are the same, you have and identity. If not, it is not an identity.

**Physics**

12.13m

**Georgia History**

am I right Ms.Sue

**Georgia History**

I think it is A,B,C

**Georgia History**

well I have 1,2,3 but I do not know 4 choose all that apply georgians were unaffected by the proclamation because they had no claim to forbidden lands. colonists were angry that the crown was protecting the americans indians, whom they had just fought in the french and indian ...

**Georgia History**

which of the following effects of the french and indian war most contributed to smuggling in the colonies? increased taxes from the crown enforcement of the navigation acts presence of british soldiers in the colonies removal of the spanish from flordia which economic system ...

**Math**

thank you

**Math**

the one with ***** that is the one I choice

**Math**

4*8 8^4 8*8 4^8******

**Math**

which expression is equivalent to 4*4*4*4*4*4*4*4

**Probability**

Lidsney inspected shipments of applices. She inspected 3 from a batch of 140 . If she finds 3 with defects the entire lot is rejected. If max knows knows that 9 of her appliances have minor defects. Find the probability that lidya will reject max shipment of appliances.

**physical science**

the answer is A.

**Georgia History**

I did but it only talks about the stuff before the royal period

**Georgia History**

Ms. Sue can you help me

**Georgia History**

I have already read theses I just need like to sentences of what developments that happened after the trustees system failed

**Georgia History**

what happened to Georgia after it became a royal colony? I am having to do a essay so I would like to know what happened.

**science**

Both carbon dioxide and water are pure substances. How are they similar to each other? A. both substances have a set ratio of atoms that cannot be separated by physical means B. both substances have a set ratio of atoms that can be separated by physical means C. both separated...

**physics help**

A block of wood experiences a normal force of 32 N from a rough,flat surface.there is a rope tied to the block.the rope is pulled parallel to the surface and the tension in the rope can be increased to 8 N before the block starts to slide. Determine the coefficient of static ...

**math**

that is correct 3+2 is five times 5 is twenty-five. you got it!!!

**math**

Compare 3+2 times 5 to (3+2) times 5. i put order of operations and got 5 times 5 for the first one, and for the second. I need to now if that is correct and if not what is wrong. thanks, John :)

**Language arts**

A dependent clause is a group of words that also contains a subject and a verb, but it is not a complete thought. Because it is not a complete thought, a dependent clause cannot stand on its own as a sentence; it is dependent on being attached to an independent clause to form ...