# Posts by Maria

Total # Posts: 1,990

**chemistry**

Calculate the pH at 25 ° C when 120 mL of a HCl solution having a concentration of 50 mM is added 50.0 mL of a 120 mM ephedrine solution. Assume no change in temperature. Amitriptyline is a drug used in treating depression. It is typically formulated as the ...

**chemistry**

presentation Tasks: Ephedrine (structure see below) is a natural product that is used as a medicine in the treatment of asthma. The corresponding acid to ephedrine have pKa = 9.60 at 25 ° C. Question: Calculate the pH reaches 991 mg ephedrine ...

**Maths**

Ahmed says that there are 70 sweet in the box to the nearest 10 what is the least number of sweets that could be in the box

**Maths**

A plane setts off from airport A and flies due east for 100 km, then turns to fly due south for 80 km before landing at an airport b show that the approximate bearing of airport b from airport a is 129

**History**

Thanks!!

**History**

Which of these words best describes a merchant? A. Explorer B. Middleman C. Monarch D. Slave I have having trouble between Explorer and middleman... I think it is B.

**biology**

Color blindness is a defect in vision of colors, this defect is due to a localize-homologous segment of chromosome X. In the document I have a pedigree which the parents and their children are normal; but then most of the children got married to a diseased one which 50% ...

**Math**

In the cafetería,100 milk cartons were put out for breakfast at the end of breakfast 27 remained. What Is the ratio of the Number of milk cartons taken to the total Number of milk cartons?

**Pre Calculus**

Two forces with magnitudes of 150 and 75 pounds act on an object at angles of 30° and 150°, respectively. Find the direction and magnitude of the resultant force. Round to two decimal places in all intermediate steps and in your final answer. Having lots of trouble ...

**Math**

What do you do when you have for sale factor 0.5 and 0.25

**Geometri euclid**

The small circle and the large circle have the same center O. Chord AB is tangent to the smaller circle at C. Prove that the area between the large and small circle is the same as the area of the circle that has AB as a diameter

**chemistry**

Assuming all gases are at the same temperature and pressure, how many milliliters of hydrogen gas must react to give 41.0 mL of NH3? 3H2(g)+N2(g)→2NH3(g)

**Chemistry**

A typical antacid contains CaCO3. If such an antacid is added to 25.0 mL of a solution that is 0.250 M in HCl, how many grams of CO2 gas are produced?

**Chemistry**

A patient received 5.0 g of NaCl in 8 hours. How many milliliters of a 0.40 % (m/v) NaCl (saline) solution were delivered?

**chemistry**

Calculate the grams or milliliters of solute needed to prepare the following solutions. 1.)75. g of a 7.0 % (m/m) KCl solution 2.) 1250 mL of a 8.0 % (m/v) NH4Cl solution 3.) 270. mL of a 15.0 % (v/v) acetic acid solution I really just need to know how to work the first ...

**chemistry**

Solubility (g/100gH2O) Substance 20∘C 50∘C KCl 34.0 42.6 NaNO3 88.0 114.0 C12H22O11 (sugar) 203.9 260.4 Using the above table, determine whether each of the following solutions will be saturated or unsaturated at 50 ∘C. 1.) Adding 19.7 g KCl to 35.0 g H2O 2.)...

**chemistry**

What volume of 0.10 M NaOH can be prepared from 250. mL of 0.30 M NaOH? A) 0.075 L B) 0.25 L C) 0.75 L D) 0.083 L E) 750 L

**chemisrty**

Which one of the following compounds will NOT be soluble in water? A) NaOH B) Na2S C) K2SO4 D) LiNO3 E) PbO

**Probability and statistic**

Suppose the counts recorded by a Geiger counter follow a Poisson process with an average of two counts per minute. Round the answers to 3 decimal places. (a) What is the probability that there are no counts in a 30-second interval? (b) What is the probability that the first ...

**college algebra**

in a class of 30 students all of them are either female or smokers. while only 5 are female and smokers. if there are 12 male smokers in the class, then how many female nonsmokers are in the class?

**Math**

Wait, I figured it out, you do 36%.

**Math**

52%, 36%, or 12%??

**Math**

A survey showed that 36% of car owners prefer two door cars, 52% prefer four door cars, and 12% have no preference. You ask 300 people. How many do you think will prefer the two door cars.

**Math**

That would be 5.

**Math**

the probability of winning a game is 25%. how many times should you expect to win if you play 20 times.

**Math**

from a barrel of colored marbles, you randomly select 5 blue, 2 yellow, 3 red, 4 green, and 2 purple marbles. Find the experimental probability of randomly selecting a marble that is not yellow.

**Chemistry**

yup

**science**

Calculate the kinetic energy in joules of a body of mass 30kg at a velocity of 3ms-1

**language arts**

which sentence best describes the employer in the original story "the ninny" and the employer in the adaptation the governess

**math**

ms.sue is right

**Science**

How test tube babies are born?

**Math**

2.A. 6,501.5 * 1000 = 6,501, 500

**English**

Yes . She got on the bus to school every day. Its correct

**Geography**

I NEED help on the introduction

**Geography**

I need help with my introduction and topics for my five paragraph essay on why the stamp act was not fair.

**life orientation**

I don't have any idea how can i answer this question..can you please help me

**English**

thank you so much here if anything

**life orientation**

Right to have free movement

**life orientation**

3 human rights violation?

**Calculus 1**

Find the formula for a function of the form y=bxe^(-ax) with a local maximum at (4,12)...

**algebra**

a 38 inch piece of steels is cut into three pieces so that the second piece is twice as long as the first piece, and the third piece is three inches more than four times the length of the first piece. find the lengths of pieces.

**Basic Finance**

Suppose we observe the following rates: 1R2= 8%, 1R2= 10%. If the unbiased expectations theory of the term structure of interest rates holds, what is the 1-year interest rate expected one year from now, E(2r1)?

**Math**

A hockey team can win, lose, or tie a match. It gets 2 points for a win, 0 points for a loss, and 1 point for a tie. It has lost 10 out of the 28 matches it has played so far, and it has 30 points. Which two equations can be used to find its number of wins, w, and its number ...

**chemistry**

For the following reaction at equilibrium, which change would shift the position of equilibrium toward forming more products? (Circle your answer(s) as there may be more than one.) 2NOBr(g) 2NO(g) + Br2(g), ∆Hºrxn = +30 kJ/mol A) Decrease the total pressure by ...

**algebra**

A large swimming pool has a perimeter of 1,028 meters, this rectangular-shaped pool is 40 meters longer than 5 times its width. Find its dimensions. width m length m

**Art**

WriteTeacher

**Art**

What did the Vogel's artworks communicate about their historical interests? They collected works that were culturally popular. They collected works that depicted revolutions. They collected works that depicted the history of cities. ( my choice ) They collected works that ...

**physics**

Which is the vector quantity that describes the shortest path between two points?

**Math**

Beta has a rope 23m long. She cutis off 1/5 of it.How long are the two pieces

**Business**

4. Which one of the following philosophies makes every employee a quality inspector for his or her own work? A. Six sigma C. Kaizen B. Quality at the source D. TQM 5. According to Maslow’s theory, what happens when a need is satisfied? A. The need disappears and won’...

**Business**

Answer D. The theory refers to control being achieved by manipulating the behaviour good or bad

**Business**

Help?

**Business**

10. Which statement is most accurate regarding reinforcement theory? A. Attainable goals lead to high levels of motivation under certain conditions. B. Perceptions of unfairness are viewed as punishments and reduce productivity. C. Management style is based on the extent to ...

**Bus.**

D?

**4th grade math**

I have 5 more red pins than yellow pins and 8 more yellow pins than green pins. The green pins are 3 centimeters shorter than the red and yellow pins. I have 18 green pins. How many red, yellow and green pins do I have

**Analytical Chem**

Equilibrium involving SO2(g), O2(g) & SO3(g) is important in sulfuric acid production. When a 0.0200 mol sample of SO3 is introduced into an evacuated 1.52 L vessel at 900 K, 0.0142 mol, SO3 is found to be present at equilibrium. What is the value of Kp for the dissociation of...

**Language**

yes 1 is B

**life orientation**

Identity three courses or study field associated with science and give 2 reasons for each

**chemistry**

3.05 g of hydrated copper sulphate produces 1.94g of anhydrous salt.assuming complete removal of all water of crystallization,determine the formula of hydrated copper sulfate

**History**

Okay thanks

**History**

Which factor contributed to growing conflict over slavery from the 1820s through the 1850s? falling crop prices rapid industrialization rising tariff rates territorial expansion** If someone could please help me out a little. I'm pretty confused and this is my educated ...

**Maths**

Thank you for answering, it really helped :) Just wondering when I am supposed to know to put x ¸ R? Thanks

**Maths**

Sorry, the symbol did not come out properly when I posted the question. The answer to the question is x followed by an equals sign with a line going through it then 1.

**Maths**

I need to solve this inequality: 3(x-1)^2 > 0 The answer is x ‚ 1, but I don't understand why the answer is not allowed to be equal to 1? Thanks :)

**math**

C 822.50

**COLLEGE**

-4 TO THE SECOND POWER + 5 =

**chemistry**

Calculate the energy (in kJ) required to heat 25 g of liquid water from 25oC to 100.oC and change it to steam at 100oC. The specific heat capacity of liquid water is 4.18 J/goC, and the molar heat of vaporization of water is 40.6 kJ/mol.

**Math**

An unknown radioactive substance has a half-life of 124 years. How long will it take a 67 grams sample to degrade to 18 grams?

**College**

-42-@ -4second power + 5 =

**Geography**

It is actually the first second, and third not the last, thanks anyway.

**Geography**

It was a typo, sorry.

**Geography**

*East Asia

**Geography**

Could someone please help, please?

**Geography**

which question would best help you analyze the population density of north korea? You have to choose 3 correct answers. How many square miles does East Asia covers? <--- Which region of North Korea has the best geography for farming? What is the population of North Korea&#...

**Math**

2,285.71

**English**

its A

**Chemistry**

Calculate the concentration of H+ ions of an aqueous solution of nitrous acid ( HNO2) to 0.02 mol/L knowing that the degree of ionization of acid is 3%

**Physics**

A 40kg mass hangs from two cables. One cable is at a 25 degree angle. The other cable is horizontally attatched to the mass. Find the tension for each cable

**Math**

George bought some CDs at his local store. He paid $15.95 for each CD. Nora bout the same number of CDs from a store online. She paid $13.95 for each CD, but had to pay $8 for shipping. In the end, both George and Nora spent the exact same amount of money buying their CDs! How...

**math**

9:21 :) Have a good day! Happy New year!

**English**

What literary device is most strongly represented in the following line from “Beowulf?” “Follower and the strongest of the Geats” A. Alliteration B. Hyperbole C. Kenning D. Caesura

**PHYSICS**

No, it cannot.

**maths literacy,agriculture, geography,tourism**

Plz help guys wth career

**Geography**

True

**Math**

2 2/5

**Pre Calc**

Solve 0=e^3x-9e^2x+20e^x

**physics**

A team of dogs drags a 81.2 kg sled 3.12 km over a horizontal surface at a constant speed.The coefficient of friction between the sled and the snow is 0.172. The acceleration of gravity is 9.8 m/s^2 Find the work done by the dogs. Answer in units of kJ.

**Algebra**

A rectangular yard measuring 25ft by 35ft is bordered (and surrounded) by a fence. Inside, a walk that is 2ft wide goes all the way along the fence. Find the area of this walk. Be sure to include the correct unit in your answer.

**Mahiga**

a sample of 0.5g gaseous alkane occupies a volume of 200cm3 at STP,find molar Mass

**physics**

A 48-kg girl stands on a 8-kg wagon holding two 19.5-kg weights. She throws the weights horizontally off the back of the wagon at a speed of 9.0 m/s relative to herself. - Assuming that the wagon was at rest initially, what is the speed of the girl after she throws both ...

**Glades academy**

The sum of twenty one and five times a number f is 61 total

**Chemistry**

112.00g of nitrogen gas is reacted with an excess or abundant amount of oxygen gas. The single product, a gas, is determined to have a mass of 431.92 g. Additional experiments showed that the product consisted of 2.0 moles. a) how many grams of oxygen reacted? b) what percent ...

**social studies**

What is social studies?social studies is when you learn about your history and they tell you what happen back then when a lot of us wasn't born and then they tell you to do your warm up.

**math**

What is temperature when you do math. In seventh grade math is hard and I don't understand what my teachers tell me they say that it is easy but i don't think it is i need a lot of help during math it used to be my favorite subject but now its not

**Solving ratio problems**

Write three equivalent ratios for each? a). 2 : 1 = b). 32 : 4 = c). 27 : 15 = d) 10/3 =

**science**

A person drive an automobile with a mass of 450 kilograms at a velocity of 26 meters per second. The driver accelerates to a velocity of 30 meters per second. The difference in the automobile's kinetic energy is how many joules?

**Algebra 2**

Can someone help me with this equation please? The directions are: Write an equation for the line in point/slope form and slope/intercept form that has the given condition. And the problem is: x-intercept = 6 and y-intercept = -8 I'm confused though I thought you needed ...

**Social Studies Check my answers!**

Ms. Sue is trying to help us learn it and understand it, not help you cheat your way through school.

**Maths**

Show that (x + 1)(x – 3)(x – 4) = x3 – 6x2 + 5x + 12 I'm so sorry but I can't show any working for this as I don't have a clue how to factorise when there are no common letters and numbers? Thanks!

**physics**

It continues to fly along the same horizontal arc but increases its speed at the rate of 1.41 m/s.Find the magnitude of acceleration under these new conditions. Answer in units of m/s