# Posts by Lisa

Total # Posts: 3,422

**Chemistry**

Calculate the pH of a solution at the endpoint of a titration involving 25.00 mL of CH3COOH at unknown concentration, and 21.40 mL of 0.100 M NaOH

**Chemistry!**

1. not sure where to find Kb as listed as 1.8E^-5? so is it 1.8E^-5= (NH4+)(NH3)/0.1-X (9.25)(4.75)/0.1-X = 439.375-X and how to I convert this to pOH and then to pH?

**Chemistry!!**

So is Ka water H2o? not sure where you got 7.20 in my chart 7.2 goes with H2PO4^- there is nothing for (H3O+) but I got 4.69 for CN- and 9.31 for HCN I am so lost...

**Chemistry**

Can the 5% approximation be used to determine the pH of the following solutions? How do I do this question? (A) 0.56 M hypochlorous acid - yes (B) 3.00 M nitrous acid - yes (C) 0.010 formic acid - no

**CHEMISTRY TITRATION Q**

because at end point the solution is neutral, so the # of moles are the same? No ...so what do I do differently??

**CHEMISTRY TITRATION Q**

The titration of 25.00mL of Ba(OH)2 solution with an aqueous solution of 0.500 M HCl reaches an end point when 30.20 mL of the HCl solution is added. Determine the concentration of M of the Ba(OH)2 solution. Soo 25.00mL=0.025L 30.20mL= 0.0302L moles= MxL (0.500M)(0.0302L)=0....

**math**

find the value of both percentages out of 100 and then add them together along with the $6.80

**college maths**

i was thinking abot 154.7 bt was not so sre and i did know it had to be less bt i didn't want to assme i wanted to know how i came up with the answer

**college maths**

One and one-half cups of native blueberries have 232 calories. How many calories does one cup of native blueberries have? (Points: 5) 233.5 calories per cup 232 calories per cup 154.7 calories per cup 0.006 Calories per cup Not sre how to calclate this one can i get some help ...

**Science**

I'm confused..What is the significance of a 1-1 line in regards to density?

**college maths**

81/800

**college maths**

some help wold really be appreciated please?

**college maths**

Write as a reduced fraction. 10 1/8% not sre how to work this one please help. 4/5 81/100 1/10 81/800

**english/grammar/manners**

Do you think us students should have to use yes or yes ma'am when answering teachers/ What do ya'pp prefer? And if so is there a comma between the words yes and ma'am/

**math**

which set is infinite? P = {positive numbers less than 60} Q = {whole numbers between 10 and 20} R = {intergers ge=reater than 18} S = {even numbers between 5 and 15}

**college maths**

subtract. 10 3/5-2 10/11= 8 38/55 7 743/55 7 38/55 Is D correct??

**college maths**

Simplify 5+1/3 1/3 1/3 {1/9+1/9} 4 1787/2187 4 1792/2187 4 1784/2187 4 22/27 Is D the best choice not sre for this one

**college maths**

wooooohooooooooo!!!!! thanks so mch

**college maths**

Translate and solve. A number n increased by 1/4 gives 1/9. Find n. (Points: 5) n=1/9 n= -5/36 n=1/36 n=1/18 is it B

**college maths**

thanks very much i now have a better understanding

**college maths**

Find the LCD and add the fractions. 1/125 + 4/50= 11/24 1/1250 1/35 551/6250 (Points: 5) im not getting the concept of this some help is really needed please

**chemistry**

10.2 g of Pb(NO3)2 are dissolved in 100 mL of water, and added to 250.0 mL of a 0.250 M solution of KI. Determine the mass in grams of Pbl2 produced, and find the number of moles of the excess reagent. PLZ explain

**chemistry**

Determine the molarity of nitrate ions in a solution prepared by mixing 25.0 mL of 0.50 M Fe(NO3)3 and 35.0 mL of 1.00 M Mg(NO3)2 Please explain fully do not know where to start?

**college maths**

??? any help

**college maths**

Ann and Grace mow the yard for $38 each mowing. During one summer they mowed 2 times and spent a total of $10 on gas. The girls split their earnings. How much did each girl receive? (Points: 5) $33 $38 $66 $76 this one is confusing its either C or D bt depends....Are they ...

**college maths**

no help??

**college maths**

its not allowing me to pt the square roots in......its someting like this 10X3X5 square root respectively 0, 3, 2

**college maths**

Write as a product of factors; then find the product. (Points: 5) 0 90 675 150 I think the answer is C but im confuse any other opinions please?

**math**

i don't know

**math**

A diameter of a circle is perpendicular to a chord whose length is 12 inches. If the length of the shorter segment of the diameter is 4 inches, what is the length of the longer segment of the diameter?

**math 104**

if a bussiness borrows $20,000 and repays $29,5000 in 5 years ,what is the simple interest rate?

**Math**

Fill in the blank so that the given statement is true. The median is 77 65,68,78,82,89,__

**Math**

Fill in the blank so that the given statement is true. The median is 77 65,68,78,82,89,__

**Math**

So false?

**Math**

A rectangular flowerpot is 20 inches long 8 inches wide and 6 inches high. true or false if andy fills the flowerpot 2/3 fullof potting soil the expression 2/3(20 + 8 + 6) could be used to find the amount of potting soil he needed

**Exponents**

GRE question - What is greater z or 60? z is the degrees of a one of the congruent sidesAn isoceles triangle

**Business Communications**

The interviewer wants to know why you got a "D" in all your English classes until this year, when you got a "B." Your best response is: (Points: 5) “I had problems writing and never thought it was important. Then, I realized that it is important, so I ...

**Business Communications**

Choose the best revision of this sentence: "I want an interview with you." (Points: 5) I anxiously await a phone call from you so that we can meet to discuss job opportunities. I can't wait to hear from you. Any time at all that you want to call and have me for ...

**Business Communications**

thank you sooo much

**Business Communications**

Which of the following is the BEST advice for increasing the number of "hits" on a scannable résumé? (Points: 5) Avoid jargon of any sort. Use a Keywords section under your name, address, and phone. Use more verbs than nouns. Use only one page. I think ...

**geology**

if the air temperature @ sea level were 23 C what would the air temperature be at a height of 2 km under avg conditions?

**Business Communications**

thank you very much really appreciate it this forum is a big help to me

**Business Communications**

Unsuccessful groups are more likely than successful groups to: (Points: 5) pay close attention to how something is said. rationalize criticism. deal directly with conflicts that emerge. make important decisions together. im not understanding this question...bt i suppose B is ...

**Business Communications**

In response to a compliment on his excellent oral presentation, a Japanese business executive replies, "No, it wasn't very good." Which of the following is the MOST likely explanation for this response? (Points: 5) He thought the person giving the compliment was ...

**Math209**

I am not understanding how to factor polynomials. Example: Factor 12y^6-40y^5+28y^4

**Chemistry**

2. Which bond is polar covalent? a) H2 b) Cl2 c) HCl d) O2

**MATH**

HOW MANY DIFFERENT WAYS COULD THE FOOTBALL TEAM SCORE 11 POINTS

**Macro economics**

if your agency hire a consultant to develop new software programs to lease at a constant cost of $ 1000 per year. the consultant say you can save $ 200 per year for every computer you purchase but you will be charged $ 100 for each harddrive you purchase . how many programs ...

**physics**

For B, the magnitude is simply the absolute value of what you got in part A.

**chemistry**

In propanol, cholesterol is 2.7 times more soluble at 43°C than at 20°C. If a saturated propanol solution is prepared at 43°C , what proportion of the cholesterol will crystallize upon cooling to 20°C?

**math**

how do i solve 8 times 493 using distributive property. then draw an array showing work

**8th grade**

Tom had scores of 78, 88, 94 and 79 on his first four science tests. What must he score on the next test to have an average of 88?

**economic**

Does diminishing marginal utility or indifference curve works for consumers? which of these concept works

**Chemistry**

write the formula for the following chemical compounds 1.Sodium sulfide 2.sulfur hexaflouride 3.Ammonium sulfate

**College Algebra**

Compounded semiannually. P dollars is invested at annual interest rate r for 1 year. If the interest is compounded semiannually, then the polynomial P(1+r/2)^2 represents the value of the investment after 1 year. Rewrite this expression without parentheses. Evaluate the ...

**Statistics**

The X2 goodness of fit can be used for both qualitative and quantitative data Is this true or false?

**vocabulary skills**

The correct answer is number 4. 100% sure that is correct answer.

**physics**

a football is kicked 40 meters. if the ball is in the air for four seconds what is the intial speed it was kicked

**physics**

a 1 kg dart moving horizntally at 10 m/s sticks to a wood block of mass 9 kg which slides across a friction free level surface. what is the speed of the block and dart after collision?

**probability**

1. A large video rental chain recently decided to change its rental policy, allowing an unlimited return date instead of requiring that movies be returned the next day. The marketing team reasoned that this would greatly increase the popularity of their stores, and also that ...

**physics**

At what temperature do the molecules of nitrogen gas have an rms speed of 34 m/s? 34 m/s is a typical highway speed for a car.

**math**

Robert Mason's account of $98.50 has been delinquent for three months. According to the office procedures manual, after 90 days a 2% service charge, compounded monthly, is added to future bills. What will be the amount owed after nine months?

**Medical Assisting**

Steri-strips cost $4.95 per box, there are 100 per box. If an orthopedic surgical group uses 200 Steri-strips a month, how much would be saved in a year by making a single purchase for a year's supply rather that 12 monthly purchases.If large lots of 1,000 or more, the ...

**Business Communications**

Im not sre of the answer

**Business Communications**

Which of the following would be an example of an emotional appeal that is part of a persuasive message? (Points: 5) "All of the ingredients we use are home-grown in the United States." "We can save 20% in labor costs if we relocate our plant to the Midwest."...

**Business Communications**

Which of the following is NOT a question you need to answer to choose a persuasive strategy? (Points: 5) What do you want readers to do? What points will the audience agree with? How strong a case can you make? What kind of persuasion does your organization value? IM CONFSE I ...

**Business Communications**

What is the BEST reason to omit the reason for the refusal in a negative message? (Points: 5) The reader may not think of the reason. The reason reflects poorly on the company. The reason benefits the reader, but not the writer. The reason is watertight. im not so sre of the ...

**chemistry**

i think I am not doing this part right (1/n5^2 - 1/n1^2)

**math**

donna runs 7 miles in 75 minutes. At the same rat, how many miles would she run in 45 minutes?

**chemistry**

i think I am not doing this part right (1/n5^2 - 1/n1^2)

**chemistry**

I think I am doing something wrong. I keep coming up with 8.72x10^17 and it is telling me I am wrong. I know D E=2.18x10^-18 x (1/1^2-1/5^2)

**chemistry**

calculate the energy of a photon emitted when an electron in a hydrogen atom undergoes a transition from n=5 to n=1 how do I do this?

**chemistry**

If 4.0 L of a 4.9 M SrCl2 solution is diluted to 40 L, what is the molarity of the diluted solution?

**chemistry**

A chemist wants to make 5.5 L of a 0.250 M CaCl2 solution, what mass of CaCl2 (in g) should the chemist use?

**College Chem**

How many mL of concentrated ammonia (14M) should be diluted to 250 mL to make a 0.75 M NH3 solution?

**physics**

Suppose I have a spring. I add a mass (m = 1.0 kg) and it is displaced by 15 cm. What is the spring constant k in units of (N/m)?

**Chemistry**

Explain, in terms of subatomic particles, the difference between S-32 and S-34

**Physics**

I have a spring on a horizontal frictionless surface. Initially it is un-stretched and at x = 0 cm. I then pull it back 10 cm and release it. What is the amplitude of the oscillations (the object has mass m)?

**Organic Chemistry**

why wash the organic layer with distilled water?

**Statistics**

Assume the body temperature of healthy adults are normally distributed with a mean of 98.2 degrees F and a standard deviation of .62 degrees F. If you have a temperature of 99.0 what is your percentile score?

**Chemistry**

Explain, in terms of subatomic particles, the difference between S-32 and S-34

**AP Chem**

the answer i -436

**english**

Okay this is my Thesis:The Internet is better in terms of providing access journals, special collections and it is quicker when searching informations than Library.While in library resources can't be checked our or be available. Is my thesis good? And the four examples I ...

**english**

I have to wrtie a paragraph in which I make claim, state thesis, can not use "For instance or for example and support with 4 examples.I choose this prompt "The internet is a much better resource for students than a library" Please tell me how to start this ...

**geology**

what is the primary basis for differentiating the eras?

**2 biology terms**

Morphology refers to the structure of something : land masses, body parts, shells, etc. Anatomical refers to anatomy which is the structure of a body (be it human or otherwise). So morphology is a more general term. You could say that anatomy is the study of the morphology of ...

**Physics**

With the energy needed to warm up some amount of water from 40C to 64C, how high could you lift it?

**college**

A dog bites a large chunk of flesh from a man's leg. The large, open wound will likely heal by the process of?

**Math**

I have two different questions. what is the set built notation of -11x-24<27-10x and write the slope intercept equation for the line with slope -5/6 and y intercept (0,4)

**Math**

Write the slope intercept equation for the line that passes through (14,-2) and is perpendicular to 7x-10y=18

**College Chemistry**

I DO NOT understand the following! Please HELP :) 1st Part Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is yellow, and C is red. In the reactions in which they participate, they are reduced to A-, B-, and C- ions, all of which are ...

**College Chemistry**

Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is yellow, and C is red. In the reactions in which they participate, they are reduced to A-, B-, and C- ions, all of which are colorless. When a solution of C is mixed with one containing A- ...

**Physics**

change in pressure=density*length*gravity

**anatomy and physiology**

When you swallow a peanut, the peanut first comes in contact with the?

**anatomy and physiology**

what cellular process involves mitosis?

**teacher aide**

still need help..

**Chemistry**

What mass of H2O is required to form 1.2 L of O2 at a temperature of 310 K and a pressure of 0.950 atm? 2H2O (l) ---> 2H (g) + O2 (g)

**math**

What is the time to double when the initial investment is $1000 and the annual rate is 3.5%

**Chemistry**

A gas mixture with a total pressure of 750 mmHg contains each of the following gases at the indicated partial pressures: , 265 mmHg; Ar 134 mmHg; and ,O2 157 mmHg; The mixture also contains helium gas.

**Chemistry**

A weather balloon is inflated to a volume of 29.6 L at a pressure of 734 mmHg and a temperature of 27.0 C. The balloon rises in the atmosphere to an altitude, where the pressure is 360 mmHg and the temperature is -13.6 C.