# Posts by cindy

Total # Posts: 1,070

**Bio**

Also, for question 2, on how to make 500 ml of a 2M sol'n of NaOH? -Wouldn't you have to take 2 M of the NaOH solution and then dissolve however many (g) of NaOH in 500 ml of water? So, 500 ml/1,000 = 0.5 L 2M = moles of solute/ 0.5 L solution = to get 1 mol of solute ...

**Bio**

How would you prepare 10L of 0.3M KH2 PO4? FW of KH2 PO4= 136.09g Before you make the solution, wouldn't you find how much solute there is first. So by using the M=moles of solute / V ? Then, you would add that amount of solute to the L of solution. ?

**Bio **

How much solute is required to make 600mL of a 0.4 M solution of Tris buffer? FW of Tris Buffer= 121.1g Work: Molarity equation= moles of solute/ liters of solution Step 1: 121.1 g / 121.14 g/mol TB = 0.9996 mol TB Step 2: Molarity Eq'n= moles of solute/ liters of sol'...

**BIO**

b) For each of these three compounds, how much solute is required to make 0.5M of a 1L solution?

**BIO**

Can someone help with this question? Here are the formula weights for three compounds often used in molecular biology: NaCl, 58.44; Tris base, 121.1; EDTA, 372.2 a) For each of these three compounds, how much solute is required to make 1L of a 1M solution?

**Math**

.15 1/5 will it equal to 3/40?

**Math**

SO if I want to simplify this 15 1/5 will it be 3/40?

**Math**

I am sorry it should be .12 1/2 , so will the answer still be the same except adding the decimal to decimal to ,6 /100 or .06/100

**Math**

yea there is, i forgot to add it in there.

**Math**

Polluted water flows into a pond. The concentration of pollutant in the pond at the t minutes is modelled by the equation c(t)= 9-90,000(1/10000+3t), where c is measured in kilograms per cubic metre. a) When will the concentration of pollutant in the pond reach 6 kg/m^3? b) ...

**Math**

Jack sold a black jacket for $150 and took 25% profit. At the same time Jack sold a red jacket for $150 and took a 25% lost. A. He lost $20 B. He lost $25 C. He lost $30 D. He gained $20 E. He gained $30

**Math**

A basketball team played 25 games. They won 7 more than they lost. How many did they win?

**Physics **

What is the polar notation for a vector that points from the origin to the point (0,5.00) ?

**Physics **

What is the displacement from a starting position of (14.0,3.0)m to a final position of (-3.0,-4.0) m?

**math**

Eight sided dice can be described as two square based pyramids stuck together at the bases. Their faces are equilateral triangles. If the edge of one die is 2mm, find the difference in materials cost between a solid gold die and a “gold” painted plastic die. (Gold ...

**read 1**

How is grandmother's dream different from reality? Last night I dreamed of an old lover I had not seen him in forty years. When I awoke, I saw him on the street. His hair was white, his back was stooped. How could I say hello? He would have puzzled all day about who the ...

**read**

5.D sorry i dont think its c

**read**

1.D 4.B 5.C i dont expect answers just help please

**read**

please help with 1,4, and 5

**read**

The Idea of Mr. Collins, with all his solemn composure, being run away with by his feelings, made Elizabeth so near laughing that she could not use the short pause he allowed in any attempt to stop him farther, and he continued: "My reasons for marrying are, first, that ...

**read**

1.Mr. Collins says he is proposing to Elizabeth because A. Elizabeth personality will displease lady Catherine B.Elizabeth has shown her affection for him C. he knows Elizabeth will inherit a lot of money D. as the heir, he feels responsible for the daughters E. he knows that ...

**Chemistry**

28.0

**Math**

In the year 1997, the surface elevation of Lake Powell was 3887 feet above sea level. In the year 2001, the surface elevation of Lake Powell was 3577.4 feet above sea level. The surface elevation of Lake Powell is at a rate of

**Grade 4 Math - fractions**

Thank you Ms. Sue for all your help! It is very much appreciated.

**Grade 4 Math - fractions **

On pet day, 18 children brought a pet to school. Two-thirds of the pets were dogs. One ninth of the pets were cats. How many were dogs? How many were cats? How many animals were neither dogs nor cats?

**Chemistry**

A sample of a substance (containing only C, H, and N) is burned in oxygen. 7.961 g of CO2, 1.164 g of H2O and 1.551 g of NO are the sole products of combustion. What is the empirical formula of the compound?

**Math**

How many cubes with 1/4-foot side lengths will fit inside 77ft3 if they are packed with no gaps

**Math**

How many cubes with 1/4-inch side lengths will fit in a 87 1/2 if they are packed with no gaps?

**biology**

you added 3ml stock solution of 0.05mg/ml of dye and 7ml of water, what will be the final concerntration.

**science**

you added 2ml of protein, 3ml of water, and 4ml of dye. how will you prepare blank for the experiment

**science**

in xperiments involving a pithball electroscope what causes the pithball to move?

**Very hard math**

It is right.

**Science**

In your own words, can you describe one way which rocks formed on Mount Moran?

**Chemistry**

Ammonium nitrate is an oxidizing agent and can give rise to explosive mixtures of mixture of two moles of powdered aluminum and 3 moles of ammonium nitrate crystals react exothermically yielding nitrogen gas water vapor and aluminum oxide how many grams of the mixture are ...

**Math**

Is that the answer or formula to go by

**ELA**

Okay thanks

**ELA**

how do I make this sentence as past perfect tense? I repair the damage from car accidents.

**Social Studies maybe?**

Maybe Hillary Clinton. IDK

**algebra**

Find the perimeter of the triangle whose vertices are the following specified points in the plane? (0,-3), (-2,1) and (-4,6)

**Analytical chemistry**

Calculate to four decimal places the mass of purely dry MgCO3(Magnesium Carbonate) required to make 1L of a 1000 ppm Mg stock solution.

**Physics**

Two identical boxcars (m = 14866 kg) are traveling along the same track but in opposite directions. Both boxcars have a speed of 5 m/s. If the cars collide and couple together, what will be the final speed of the pair?

**physics**

A rectangular loop of wire is placed next to a straight wire, as shown in Fig. 20–55. There is a current of 3.5 A in both wires. Determine the magnitude and direction of the net force on the loop

**Physics**

If the pole-vaulter were to land on concrete rather than on a cushion, the impulse that stops the fall would be what? A) Greater because of the rigidity of the concrete. B) Greater because of the force of impact is greater. C) The same because impulse is the change in momentum...

**astronomy**

The isotope potassium-40 (40K) decays into the isotope argon-40 (40Ar) with a half-life of 1.25 billion years. Suppose we find a rock in which seven-eighths of the potassium-40 has decayed to become argon-40, and only one-eighth of the original potassium-40 remains.

**math**

figure (N) 1 , 2 , 3 Number of Square (S) 2 , 7 , 12 What is the formula?

**Math**

pattern Sort sticks Long sticks number (n) (S) (L) 1 4 2 2 7 4 3 10 6 find formula

**Math**

Simplest form for 2/3 times21

**Chemistry**

An unknown compound contains only C, H, and O. Combustion of 3.70 g of this compound produced 9.03 g of CO2 and 3.70 g of H2O. Im so confused.

**Kaplan**

Ricardo and Jessica are traveling towards each other from points that are 603 miles apart. If Jessica is traveling 9 mph faster than and they meet after 9 hours, how fast was each traveling?

**math**

7*1, 7*3, 7*9, 7*27, 7*81 looks like 7* 3^(x-1) I don't understand how you got (x-1) can you explain?

**math**

1. Examine the first four terms in each of the following number sequences: *2, 7, 12, 17 my formula x+5 *7, 21, 63, 189, 567 my formula x(2)+x *1000, 850, 700, 550 my formula x-150 * –10, –6, –2, 2 my formula x+4 For each sequence, what would be the 20th and ...

**Math**

Lesson is on using formulas A=l*w Create formulas for the following relationships. A. The relationship between the number of tires (not including spares) and the number of cars in a parking lot. B the relationship between the number of minutes to the number of days.

**Math**

Simplify 3(x+2)-4(5-x) Is this how you do it 3x+6-20+4x 7x-14 Is there a way to use a calculator for this

**Math**

Solve 2c+3t=35 for c

**Math**

Is there different ways to solve for 4x-5=9+2x

**math**

At the malt shop a large chocolate shake takes 8/9 of a pint of milk. If the medium shake takes 1/7 the amount of a large, how much does the medium shake take?

**Math**

Jason measured rainfall for a science project. Last week it rained 3 1/8 inches in all. This week it rained 1 7/8 inches in one day and 2 3/4 inches on another. How many more inches did it rain this week then last week? Please explain how you got your anwser

**literature arts**

Height

**Modeling our world**

In the Fall Semester, many high schools hold special events to welcome students back to school and to help the students new to the school get into the spirit of the new year. The Student Council decided to order spirit ribbons for all students to wear at a special assembly. ...

**Math**

In an used book store, there are some different mystery novels on a shelf. Suppose there are 64 different ways to buy these novels, including not buying them. How many mystery novels are there on the shelf?

**Math**

A committee of 5 people is to be formed from a group of 7 women and 4 men. How many possible committees can be formed if: the committee then must chose a president and a vice president, how many ways could these two positions be chosen? why is it permutations not combination? ...

**Math**

A circular window has a diameter of 25 inches. It's approximation is 22/7

**science(chemistry)**

1.33 M

**Math**

Gunny has a sheet of plywood that is 4 feet by 8 feet she wants to saw the plywood into pieces 1 foot high and 2 feet long for signs How many signs can she make with the sheet of plywood?

**Math Help**

Find the Area: f(x)=sin6x and g(x) = cos 12x, -pi/12 less than or euqal to x is less than or equal to pi/36

**math**

Find the area: f(x)=sin6x and g(x) = cos 12x, -pi/12 less than or euqal to x is less than or equal to pi/36

**Math**

Martin paid $120 towards his $2400 credit card bill. What percentage of his bill did he pay?

**Math**

If f[g(x)] = x, then f(x) and g(x) are inverses of each other. Why? I don't get this in my math question.

**Life Orientation**

for research

**math**

6,-7/5

**life orientation**

bill of rights

**Math**

This is on the 2008 Free response AP Calc AB exam- #4a. Let f be the function given by f(x)=(lnx)(sinx). The figure above shows the graph of f for 0<=x<=2pi. The function g is defined by int{1,x} f(t)dt for 0<x<=2pi. a) find g(1). I don't get why it is equal to...

**Math about weight**

I tried it's very late. Subtract .8 and 3 lbs from 32 lbs. then divide it by 8 liters?😂

**Math**

If there is a hole exactly in the middle of a 15 foot walk and the hole is 2.3 feet wide how far are the edges of the hole from edges of wall?

**Math grade 7**

Chelsea has a hole exactly in the middle of her 15 foot long walk, right where the floor and the wall meet. If the hole is 2.3 feet wide, how far are the edges of the hole from the edges of the wall?

**Math Grade 7**

you want to put a place mat that is 11.5 inches long directly in the center of a table that is 40 inches long. How far is the place mat from either edge of the table?

**math**

prove that 2sinA + 1 / cosA+sin2A=secA

**English**

Any traditional marriage

**math**

why a negative -240?

**math**

This question was in a math competition on April 2nd. I could The answer given was 48853.00

**math**

Nick would like to purchase a vacation timeshare, but he can only afford a $350 monthly loan payment. He wants the loan to extend 20 years, and the annual interest rate is 6%. How much money will Nick need to borrow if he repays the loan at $350 per month over the 20-year ...

**Math**

Suppose that INT{pi to t} g(u)du= e^(cos(t)). Show that INT{0 to t}g(u)du= e^(cos(t))- e. I have no idea how to prove. Tried taking derivative of the result, but didn't think that would help with anything.

**Algebra**

For a nonsmoker, the biological half-life of theophylline is 8 hours. Find the amount of the drug retained in a nonsmoker's system 18 hours after taking a one-unit dose. (Round your answer to three decimal places.)

**Math**

There are 12 gum balls,(each a different color), in a bag. One of them is red. What is the probability of reaching into a bag without looking & selecting a color that is not red?

**Math**

How does [(512)^x * ln(2)]/ln(512) simplify into ((512)^x)/9??

**Calculus**

How to do this vertical slicing question: find the area under the curve for the function y=(2x+1)^2 of the interval -1<=x<=3. I am not sure how to do this, but it may involve breaking the integral up. How though?

**Calculus**

Integrate dx/(sqrt(x^2+16)). I have no idea how to start and which method to use. Thinking some sort of trig substitution? But it doesn't look like it. Step by step? Answer key says ln|x+ sqrt(x^2+16)|.

**Calc**

Integrate (x+4)/(x^2+5x-6). I got 2/7ln(x+6)+5/7ln(x-1). But wolfram says 2/7ln(x+6)+5/7ln(1-x). Why is it 1-x instead of x-1??

**Math**

Using FTC(fundamental theory of calculus) evaluate the derivative of: (definte integral- lower bound 0 and upper 2) ∫|2x-1|dx I have no idea how to do this, especially because the dx is on the same side of the equation. It is usually d/dx, but this is also on the other ...

**Physics**

A 4.70 nC point charge is placed at the centre of a hollow metal sphere that has an inner radius 4.70 cm and an outer radius 17.6 cm. The metal sphere itself is charged to 8.40 nC. a)What is the magnitude of the electric field at a distance of 1.60 cm from the centre? b)What ...

**science**

14. A vehicle that goes from 5m/s to 45m/s in 8s. What is its acceleration?

**Science**

I need the know how many squares of a grap, if 1/6"=3'. I need to make a floor plan.

**Algebra**

An auditorium seats 1500 people. Floor seats cost $15 and balcony seats cost $10. If the place is sold out and they make $2100 how many seats are on the floor and in the balcony?

**math**

Graph two equations to determine every real number whose square equals its cube. I am so confused!

**geography**

The lengths of two sides of a right triangle are 12 inches and 15 inches. What is the difference between the two possible lengths of the third side of the triangle? Round your answer to the nearest tenth.

**Chemistry**

Calculate the total mass of aluminum, with 90% purity, required to produce 448g of iron in the process Fe2O3 + 2 Al = Al2O3 + 2 Fe

**math**

prove 3cos theta - cos3theta = 2cos theta cos2theta + 4sin theta sin 2theta

**math**

jenny needs to make a total of 85 deliveries this week. so far she has delivered 34 of them. what percentage of her total deliveries has jenny completed? how do u figure this out please

**math**

how do i figure out the percent increase from 0.c0 cents to 0.25 cents?

**math**

For his exercise today, Trey plans to both run and swim. let r be the number of laps he runs and let s be the number of laps he swims. each lap he runs takes him 5 minutes and each lap he swims takes him 2 minutes. he wants to exercise for more than 45 today. Write an inequality