1. Chemistry

N2H4 + 2H2O2= N2 + 4H2O What are the mole ratios of hydrazine (N2H4) to hydrogen peroxide (H2O2) and hydrazine to water

2. Chemistry

In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?

3. physics

A hiker begins a trip by first walking 25.0 km 45.0° south of east from her base camp.On the second day she walks 40.0 km in a direction 60.0° north of east, at which point she discovers a forest ranger’s tower.Find the magnitude of the displacement

4. Chemistry

Why do different substances have different Rf values ? used in chromatography.

5. Math

Mr.Adams had a coin collection including only nickels, dimes, and quarters He had twice as many dimes as nickels and half as many quarters as he had nickels. If the total face value of his collection was \$300.00, how many quarters did the collection

6. science

6.025*10^20 molecules of acetic acid are present in 500 ml of its solution .What is the concentration of the solution?

7. pre cal

The vector u = (4300, 5200) gives the number of units of two models of laptops produced by a company. The vector v = 1800, 1200 gives the prices (in dollars) of the two models of laptops, respectively. Identify the vector operation used to increase revenue

8. Science

If you weigh 300 N on earth, then what is your mass and weight in mars?

9. Math

The expenses of orphanage are party constant and partly vary as the number of the boys in the orphanage. The expenses were Rs. 10,000 for 150 boys and Rs. 8,400 for 120 boys . Find the expenses for 330 boys.

10. Chemistry

1.06g of Na2CO3 is dissolved in water to make 250cm^3 solution. 10.0 cm^3 of this solution was further diluted to make 500cm^3 of 2nd solution. 25.0cm^3 of 2nd solution reacted with 28.5cm^3 of HCl. Find the concentration of HCl in mol/dm^3

11. Math

Line a intersects line b, forming angles of 135 degrees and 45 degrees. A third line,line c, is perpendicular to line a and forms triangle ABC. What is the measure of the angle between lines b and c? a. 35 degrees b. 45 degrees c. 90 degrees d. 135 degrees

12. English

1. She spoke in a very loud voice. 2. She spoke in a very high voice. 3. She spoke in a very low voice. 4. She spoke in a very soft voice. 5. She spoke with a very loud voice. ----------------------------------- Does #1 mean #2? Can we use both #3 and #4?

13. Socials Studies

Why were the rules of the bison hunt so strict? Why might some punishments involve destruction of property? The rules were so strict because it was dangerous and can cause death and serious injuries. Am I right? That's my answer for the first question and

14. Microsoft Word 2013

You often insert your company's logo into documents you create. One way to make it easier for you to quickly insert it is to save the logo as a A. custom block. B. text block. C. building block. D. shortcut. My answer is C.

15. math

Given that Force 1 = 70 pounds and Force 2 = 120 pounds , find the angle between the forces if the magnitude of the resultant force is 90 pounds . Round answer to the nearest degree.

16. Math

When an object is droped from a certain height , it's distance from the starting point varies as the square of the time it has been falling . If a body falls through 288m in 6 seconds then what is the distance covered by the object in the tenth second?

17. Chemistry

Why water can be used as a solvent in paper chromatography?

18. Microsoft Word 2013

10. _______ allows you to specify how a photo is positioned in the text of your document. A. Align Photo B. Align Text C. Wrap Photo D. Wrap Text My answer is a.

19. Data Analysis with spreadsheets with Lab

Using the IF function calculate the commission on sales. The commission is 6% on all sales that are at least 20% above cost.

20. algebra

A ball is launched from a slingshot. Its height, h(x), can be represented by a quadratic function in terms of time, x, in seconds. After 1 second, the ball is 148 feet in the air, after 2 seconds the ball is 272 feet in the air. Find the height in feet of

21. Microsoft Word 2013

What is the default file extension for a file saved in Word 365? A. .docext B. .doc365 C. .docx D. .doc My answer is C.

22. maths

The minute hand turns through __________ degrees from the digit 2 to 11 on a clock

23. Strayer Math

Latoya ran for president of the chess club, and she received 18 votes. There were 40 members in the club. What percentage of the club members voted for Latoya?

24. medical insurance

the patient is seen by his family physician for follow-up treatment of recently diagnosed asthmatic bronchitis. the physician's fee is 75\$. the patient copayment is 20\$, and the patient is not required to pay any additional amount to provider. the payer

25. Math

A record playa with a speed of 33 1/3 revolutions per minute, meaning that a needle in a groove around te edge of the record will make 33 and 1/3 circuits around the record in one minute. If the diameter of the record is 40 centimeters, how many

27. physics

a motorcyclist drives from a to B with a uniform speed of 30km/h find its average speed

28. Maths

Mary has 6262 square blue tiles and a number of square red tiles. All tiles are the same size. She makes a rectangle with red tiles inside and blue tiles on the perimeter. What is the largest number of red tiles she could have used?

29. Science

Calculate the amount of water produced by the combustion of 44g of propane and 16g of methane.

30. Math

On Feb. 27th, 2010, an earthquake of magnitude 8.8 occurred off the coast of Chile lasting up to 3 minutes. Five months later, a 2nd earthquake occurred with magnitude of 5.3. How much more intense was the first earthquake compared to the 2nd earthquake?

31. English

1. However hard you may study, you can not get a good point. 2. However hard you may study, you can not get a good grade. 3. However hard you may study, you can not get good points on the exams. 4. However hard you may study, you can not get good grades on

32. pharmaceutical physical chemistry

find the density of NH3 gas at 100celsius when confined by a pressure of 1600mmHg

33. Physics

A kid puts 0.12 J of energy in compressing a toy.To which height will the toy rise if the mass of the toy is 0.012kg?

34. homework

The number of bacteria in a certain population increases according to a continuous exponential growth model, with a growth rate parameter of 3.9% per hour. How many hours does it take for the size of the sample to double?

35. Math

A taco stand sells tacos with any three ingredients for a flat price of \$1.25. Additional ingredients cost \$0.50 each. There are ten different possible ingredients. How many different types of tacos costing \$2.25 can be made at the stand? A. 160 B. 252 C.

36. English

1. He took a picture of the mountain. 1-1. He took two picture of the mountain. 2. He took pictures of the mountain. 3. He took many pictures of the mountain. 4. Will you take a picture of us? -------------------------------- Q1: Are they all grammatical?

he Supreme Court decision in the case of Brown v. Board of Education was important because it exhibited __________. A. the use of the affirmative action policy B. the scope of flexibility of the law C. the state's supremacy over federal rulings D. the

38. Health

What do obesity trends presented by surveillance systems help with? present trends in colorful, creative maps change behavior about the obesity problem in the U.S. they do not tell us much raise awareness about the obesity problem in the U.S. C?

39. Math

A record playa with a speed of 33 1/3 revolutions per minute, meaning that a needle in a groove around te edge of the record will make 33 and 1/3 circuits around the record in one minute. If the diameter of the record is 40 centimeters, how many

Alexis has a pencil bag containing one of more of each of the following: red pens, blue pens, mechanical pencils, and black markers. He knows that there is a 4% chance he will pull a red pen out of the bag if he chooses randomly. What is the number of

41. math

a number rounds off to 4000.The digit in the hundreds place is twice the digit in the tens place.The sum of the digits is 12.The number uses only two different digits.Find the number.

42. Math

The sound intensity of a soft whisper is about 1/200000 of the sound intensity of a shout. What is the decibel level of a whisper if a shout has a loudness level of about 85 dB? L = 10log(i1/10^-12)

The concept of federal law taking precedence over state or local law is commonly called the __________. A. Preemption Doctrine B. Bill of Rights C. Due Process Clause D. Free Exercise Clause Answer :B

44. Maths

By how much taller is the door 2meters than the boy 78meters

45. physics

a heavy object is dropped from the top of a 25 m tall building and it reaches the ground in 2.26 seconds determine the acceleration due to gravity how far did the object fall during the first second how far did the object fall during the 2nd second

46. Math

If the battalion of soldiers is formed into a solid square,there would be sixteen fewer men in the front than there would be if they were formed into hollow square four deep. What is the required number of the soldiers.?

47. English

1. I'm a power blogger, so I try to upload postings and pictures every day. 2. I'm a powerful blogger, so I try to upload postings and pictures every day. --------------------- Q1: Can we use 'powerful' in place of 'power'? Q2: What does 'postings' mean?

48. Math

In phythagorean triplet how to find numer 7

49. health communication

For your communication intervention, you are trying to get young mothers in a developing country to use more nutritious complementary food for their infants. You find that their mothers-in-law make most of the decisions, so you try to convince them first

50. MATH

if log_a 3 = log_b 27 then show that b=a^3 log_a mean log base a.

51. English

1. She pulled him gently towards her. 2. She pulled him gently towards herself. ------------------------ Can we use both expressions? In Sentence 2, a reflexive pronoun is used. Is #2 correct?

52. Vectors

Show that the line with parametric equations x = 6 + 8t, y = −5 + t, z = 2 + 3t does not intersect the plane with equation 2x − y − 5z − 2 = 0.

53. physics

A stone thrown upward at the top of the tower reaches the ground after 5 sec. A second stone is thrown down with the same speed and reaches ground in 3 sec. What is the height of the tower

54. Geometry

Find the area of the shaded region, if the rectangle has dimensions 8m and 18m and the circle is inscribed in the rectangle. I just need an example on how to solve for this. I'm pretty bad at following without examples and my book doesn't show one.

The __________ clauses in the Constitution collectively prohibit states from enacting laws that unduly discriminate in favor of their residents. A. Due Process B. Equal Protection C. Establishment D. Privileges and Immunities

56. Algebra

How far could you drive for \$90?

57. Math

After solve a function I get these X>_-1(greater than equal to) X>_3 & X>_2?what will be it's domain?

58. Math

For what value of k will the following function have y-intercept of 5. log{base 3} (-5x +k^2)-1

59. Math

Mapping Notation for y=2log _3(-3x +9)-2 log_3 mean log base 3

60. Math

If I travel 200 feet in 2.92 seconds what is speed I'm traveling at

61. pre cal

Find the angle between the vectors u and v if u = (-1,4) v = (3,-4) a. 155.93 b. 158.58 c. 158.13 d. 155.24 e. 157.17

62. pre cal

Find the angle between the vectors u and v if u=i+4j and v=−i+2j.

63. mathematics

How many numbers upto 450 are divisible by 4,6,8

64. Math

equation log_b a = c. a) If 0 < a < 1 < b, what can you conclude about c? b) If a < 0 < 1 < b, what can you conclude about c? Please help !

65. physics

the driver of a truck going 50 mph applies the brakes giving the truck a deceleration of 4.5 m/s^2 how long will it take the truck to come to a complete stop what distance will it cover

66. physics

the maximum possible speed a certain car can achieve is 80 m/s (about 180 mph) the car covers a distance of 1km while accelerating up to this speed from rest how fast is the car moving at the halfway point of 500m (the answer is not 40m/s) at what point is

67. MATH

Suppose the annual expected mortality rate from coronary disease is 500 per 100,000 individuals. In a specific community of 600,000 individuals, how many deaths are expected to be attributed to coronary heart disease over a one year period? my work:

68. English

1. I got out of my car to check the engine. 2. I got off my car to check the engine. (Are both the same? In #2, what is the part of speech of 'off'? Is 'off' an adverb or a preposition?) 3. I got out of my car to check the engine. 4. I got out of my car to

69. college chemistry

prepare 0.2M phospate buffer of pH 5.7

70. Math

A taco stand sells tacos with any three ingredients for a flat price of \$1.25. Additional ingredients cost \$0.50 each. There are ten different possible ingredients. How many different types of tacos costing \$2.25 can be made at the stand? A. 160 B. 252 C.

71. Science-light

Shawn wanted to find out which of the four materials A, B, C and D allows the most light to pass through. He was given the following items: - A torch - A ruler - A light sensor connected to a datalogger - Four different materials A, B, C and D Shawn

72. science

if the velocity of a progressive wave with a periodic frequency of 10khz is 330m/s.calculate it's wavelength.

73. math

What is the volume of a balikbayan box with a length of 21√5 inches, width of 12√3 inches and a height of a 25√3 inches? Thank youu!!

74. Math

Three dozen eggs, 25% broken. How many left? ( Answer with working outs) please.

75. Math

Write an equation for a log functions base 2 whose graph has the following properties: vertical asymptote of x=-6 Domain of x

76. Algebra

coffee shop sells small and large coffee. Each day they sell 510 cups of coffee. If the shop sells 3 times as many large cups as small cups of coffee, How many cups of each size do they sell daily?

77. Math

If a family plans to have four kids what is the probability that they will have at least one girl

78. Math

Determine u⋅v if u =5, v =3,and θ =π/3 ,where θ is the angle between u and v. A) 7.50 B) 12.99 C) 10.61 D) 10.25 E) 9.05

79. MATH

What f-1(x) of f(x)=(1/3)^x

80. physics

a sports car can accelerate fo 0 to 60 in 3.2seconds what is the acceleration of the car in m/s^2 what distance would it travel at this time

81. physics

a driver traveling 42 mph speeds up to 58 mph over distance of 660 feet how long does this increase in speed take what is the driver's acceleration

82. Calculus

How do you differentiate sin^2(cos t) My work: =2sin(cos)(cost)(-sint)

83. Math

Write an equation for a log functions base 2 whose graph has the following properties: vertical asymptote of x=-6 Domain of x