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Most popular questions and responses by eng
1. chemistry

1)The reaction of methane and oxygen yields carbon dioxide gas and water. The unbalanced reaction is as follows: CH4(g) + O2(g)CO2(g) + H2O(g) A. If 0.718 grams of methane are reacted, how many grams of water vapor are produced? B. If 1.621 grams CO2 are

2. chemistry

Based on the balanced equation 2Al + 6HCl → 2AlCl3 + 3H2 calculate the number of excess reagent units remaining when 140 Al atoms and 402 HCl molecules react?

3. Physics

A potential energy function for a two-dimensional force is of the form U = 3 x^(4)y - 8 x. Find the force that acts at the point (x, y). (Use x and y as appropriate.) I know its something about partial derivatives but I'm not sure how to go about it. And

4. chemistry

Gaseous carbon monoxide reacts according to the balanced equation. If a total of 1040 kJ of heat is generated in the reaction as written, how many grams of CO2 are produced? enthalpy=-566kJ 2 CO(g) + O2(g) → 2 CO2(g)

Which equation describes the relationship between the rates at which Cl2 and F2 are consumed in the following reaction? Cl2(g) + 3F2(g) yield 2ClF3(g) a)-d(Cl2)/dt = -d(F2)/dt b)-d(Cl2)/dt = 2[-d(F2)/dt] c)3[-d(Cl2)/dt] = -d(F2)/dt d)2[-d(Cl2)/dt] =

6. chemistry

CoSO4 + KI + KIO3 + H2O  Co(OH)2 + K2SO4 + I2 2KI yield I2 + 2e 2KIO2 10e yield I2 are there 10 electrons being transferred or just 5 only

7. chemistry

Based on the balanced equation 2Ba + O2 → 2BaO calculate the number of BaO formula units formed when 142 Ba atoms and 73 O2 molecules react?

8. math

for this infinite series (-1)^n/n^2 if i use alternating series test to show that sequence does of a^n does not go to 0, then does this mean that this series is diverging

9. chemistry(check my work)

If 6.01 g of K2SO3 dissolved in 930 mL of water reacts stoichiometrically according to the balanced equation in a reaction solution with a total volume of 990 mL, what is the molarity (M) of KCl produced? K2SO3(aq) + 2 HCl(aq) → SO2(g) + 2KCl(aq) +

10. chemistry

Which equation describes the relationship between the rates at which Cl2 and F2 are consumed in the following reaction? Cl2(g) + 3F2(g) yield 2ClF3(g) a)-d(Cl2)/dt = -d(F2)/dt b)-d(Cl2)/dt = 2[-d(F2)/dt] c)3[-d(Cl2)/dt] = -d(F2)/dt d)2[-d(Cl2)/dt] =

11. chemistry

Pt(s) | Mn2+(aq), MnO4-(aq), H+(aq) || H+(aq), IO3-(aq) | I2(s) | Pt(s) Pt(s) | Mn2+(aq) | MnO2(s) | H+(aq) || H+(aq) || PbO2(s) | Pb2+(aq) | Pt(s) how come the first one has comas within cell notation but not the second one,

12. chemistry

A balanced equation that represents an overall cell reaction is shown. Choose the cell notation which corresponds to the electrochemical cell that is described by this equation. 2H2O(l) → 2H2(g) + O2(g) i don't get why the answer is this. How can OH-

13. chemistry

1)RuO2 is molecular, but why is it insulator even though Ru is metal? 2)Why is TiO ionic? I thought only group 1 and 2 would make ionic compound 3)If the the compound has metal and metalloid like GaAs, is it always semiconductor

14. chemistry

for the reaction, determine the number of transferring electrons so then i can pug into G=-nFE I'm assigning charges to each of the elements H2O2(aq) + 2ClO2(g) → O2(g) + 2HClO2(aq) (+1,-1) + (+4,-2) (0) (+1,+1,-2) since O changes from -1 to 0, so it

15. chemistry

Does the basicity decreases as going down the column and right across the periodic table? How does the size of an element or electronegativity apply to strength of basicity and acidicity?

16. chemistry(check my steps)

The electrochemical cell described by the cell notation has a standard cell potential of -0.35 V. Calculate the Wmax (kJ) the cell has done if 1893.5 g of MnO42-(aq) (Molar Mass - 118.94 g/mol) forms. Round your answer to 3 significant figures. Pt(s) |

17. chemistry

how do i write this reaction in cell notation I2(s) + 2MnO4-(aq) + 4H+(aq) → 2IO3-(aq) + 2Mn2+(aq) + 2H2O(l)

18. physics

An auditorium measures 35.0 m multiplied by 15.0 m multiplied by 5.0 m. The density of air is 1.20 kg/m3. What is the weight of air in the room in pounds? i got 4.25 x 10^5 and the page says that "Your response differs from the correct answer by orders of

19. chemistry

The electrochemical cell described by the cell notation has a standard cell potential of -0.35 V. Calculate the Wmax (kJ) the cell has done if 1893.5 g of MnO42-(aq) (Molar Mass - 118.94 g/mol) forms. Round your answer to 3 significant figures. Pt(s) |

20. chemistry(check my work on anothe rproblem)

When a reaction mixture with a total volume of 1390 mL that is 0.00791 M aqueous Ba2+ was stoichiometrically produced as per the balanced equation, what mass (g) of Ba2+ was required? Ba(OH)2(aq) + 2 HClO4(aq) → Ba(ClO4)2(aq) + 2 H2O(l) .00791x1.39=mole

If 0.836 g of solid Al reacts stoichiometrically according to the balanced equation in a reaction solution with a total volume of 1160 mL, what mass (g) of gaseous H2 is produced? 6 HClO4(aq) + 2 Al(s) → 3 H2(g) + 2 Al(ClO4)3(aq) 0.836g/molecular weight

22. chemistry

1)gaseous sulfur trioxide and gaseous nitrogen monoxide form when gaseous sulfur dioxide and gaseous nitrogen dioxide react. 2)Enter the formula of the missing substance ( Y ) in the balanced equation below. Do not give the coefficient. C2H4 + 3Y → 2CO2

23. physics

An automobile tire is rated to last for 60,000 miles. To an order of magnitude, through how many revolutions will it turn? i put 10E7 but i got it wrong since i used 1rev/8ft

24. chemistry

Based on the balanced equation 2I2O5 + 10NO → 5N2O4 + 2I2 calculate the number of excess reagent units remaining when 188 I2O5 molecules and 850 NO molecules react? do i start with a new balance equation in order to solve it

25. chemistry

Which of the following rate laws suggests that the reaction probably occurs in a single step? why is this problem cant be answer a since it has order of 1 a)(CH3)3CBr + OH- →(CH3)3COH + Br- rate = k[(CH3)3CBr] b)NO(g) + O2(g) → NO2(g) + O(g) rate =

26. chemistry(check my work)

When a reaction mixture with a total volume of 1720 mL that contains 0.605 L of gaseous CO2 measured at STP dissolved in 940 mL of water was stoichiometrically produced as per the balanced equation, how many mol of solid CaCO3 were required? H2SO4(aq) +

27. chemistry

Liquid quinoline reacts according to the balanced equation. When 1200 g of C9H7N is reacted, calculate the sign and magnitude (kJ) of the heat produced. 4 C9H7N(l) + 43 O2(g) → 2 N2(g) + 36 CO2(g) + 14 H2O(l) .

28. chemistry

Using the balanced equation, determine the number of NaNO3 units in the visualization in the reaction. 3Ca(NO3)2(aq) + 2Na3PO4(aq) → 6NaNO3(aq) + Ca3(PO4)2(s)

29. chemistry

Wich of the following is NOT true about the blank for the experiment, 'Analysis of a Complex Iron Salt'? A. A blank is titrated to correct for any reactive impurities in the solvent. For this experiment, the impurities would be reducing agents that would

30. chemistry

If 0.755 g of Al3+ dissolved in 960 mL of water reacts stoichiometrically according to the balanced equation, what volume (mL) of 0.0875 M aqueous Cl- is required? Al2(SO4)3(aq) + 3 BaCl2(aq) → 2 AlCl3(aq) + 3 BaSO4(s)

31. math

for a strict triangular form, does it has to be in I matrice or just the main diagonal entries are all 1]\

32. chemistry

HCl (aq) + Cu (s) + HNO3 (aq) yield CuCl2 (aq) + NO (g) + H2O (l) do i say that HNO3 is oxidizing agent or just N+5 is the oxidizing agent

33. physics

if the system is a basket, the basket is tied to a rope and it is stopped by a fixed clamp when it is falling down, I know there is initial KE but how come initial work is negative. Isnt force and displacement are in the same direction, so work should be

34. chemistry

Which of the following rate laws suggests that the reaction probably occurs in a single step? why is this problem cant be answer a since it has order of 1 a)(CH3)3CBr + OH- →(CH3)3COH + Br- rate = k[(CH3)3CBr] b)NO(g) + O2(g) → NO2(g) + O(g) rate =

Which of the following will be affected by the addition of a catalyst to a chemical reaction? a)the value of the reverse rate constant, kr b)the magnitude of the equilibrium constant c)the value of the forward rate d)ΔHo e)the value of the forward rate

Which equation describes the relationship between the rates at which Cl2 and F2 are consumed in the following reaction? a)-d(Cl2)/dt = -d(F2)/dt b)-d(Cl2)/dt = 2[-d(F2)/dt] c)3[-d(Cl2)/dt] = -d(F2)/dt d)2[-d(Cl2)/dt] = -d(F2)/dt e)-d(Cl2)/dt = 3[-d(F2)/dt]

37. chemistry(check my work)

Which of the following is NOT true of colligative properties? Colligative properties are... A. dependent on the mass of solute present. B. independent of the chemical identity of the solute. C. dependent on the molar mass of the solute. D. responsible for

38. calculus

why is lim of tanx as x approaches to (pie/2)+ is negative infinity. Shouldnt it be positive infinity since pie/2 is approaching on the right

39. chemistry

is CaO soluble

40. chemistry

1) Calculate the specific heat capacity (J/g oC) of iron, if a 803 g sample lost 937.4 J of heat energy in going from an initial temperature of 5.50 oC to a final temperature of 2.90 oC. 2)Calculate the final temperature (oC) of a 243 g sample of water

41. chemistry

If 600 mL of 1.05 M aqueous CaCl2 and 720 mL of 0.792 M aqueous Na3PO4 are reacted stoichiometrically according to the balanced equation, how many milliliters of 0.792 M aqueous Na3PO4 remain? Round your answer to 3 significant figures.

42. chemistry

Based on the balanced equation, 10Li + N2F4 → 4LiF + 2Li3N calculate the formula units of LiF formed when 54 molecules of N2F4 are reacted. since one mole of N2F4 yields 4LiF, then 54N2F4 yields 216LiF, am i correct

43. chemistry

Transfer the tablet to a clean 125-mL Erlenmeyer flask. Add 10-mL of 1M NaOH and heat the mixture to a gentle boil. Once the solution has cooled to room temperature, transfer it to a 100-mL vol. flask. Using the diluted solution from the 100-mL volumetric

44. chemistry

1) 14 moles of Ar 12 moles of N2 2 moles of BF3 If the total number of mol present in the mixture visualized is 1.43, calculate the number of mol of N2. 2) 11 moles of N2 4 moles of CSH4 If the total number of mol present in the mixture visualized is 1.68,

45. chemistry

Infrared, ultraviolet, and visible radiation are all part of the electromagnetic spectrum. Arrange the three types of radiation in order of increasing energy? i put visible

46. chemistry

A. What is the mass of Solution 3? in g B. What is the density of Solution 2? g/ml solution 1: Mass Empty Flask (g):42.252 Mass NaCl (g):0.911 Volume Water (mL):100 Mass of Flask + Solution (g):43.107 solution 2: MEF: 45.778 mass nacl:0.897 volume water:

47. chemistry

do we have buffering region and ph=pka in any of these conditions: strong base vs strong acid strong base vs weak acid weak base vs strong acid weak base vs weak acid

48. chemistry(check my asnwer)

Why doesn't potassium ion K+ from KMnO4 appear in the following two unbalanced equations: MnO4– + C2O42– Mn2+ + CO2 MnO4– + Fe2+ Mn2+ + Fe3+ ? A. KMnO4 is not added to either reaction. B. The presence of K+ would result in a net positive charge in

49. chemistry(check my explanation)

sorry to repost this question but i'm confused on this part The solubility of borax is directly proportional to temperature. Therefore, the sign of H is A. negative B. positive C. unknown with the given information like you said earlier, borax dissolves

50. chemistry

When a reaction mixture with a total volume of 1750 mL that is 0.0263 M aqueous K+ was stoichiometrically produced as per the balanced equation, what volume (mL) of 0.0326 M aqueous K3PO4 was required? 3 BaBr2(aq) + 2 K3PO4(aq) → Ba3(PO4)2(s) + 6 KBr(aq)

51. chemistry

A 1.00 L volume of 0.609 M HNO3 is condensed to a volume of 0.750 L, calculate the molarity (M) of H+ in the new solution

52. chemistry

Calculate the molality (m) of CH2Cl2 in a solution generated by combining 846 g of the solute CH2Cl2 with 11.2 L of the solvent ethanol.

53. science

if i use 30 ul from a total volume of 600ul to get 40ug/ml. So to get the total ug only, do i take 40ug/ml*.030ml*(600ul/30ul)=total ug

54. electrical engineering

Input range: -100mV to +60mV Voltage supplies to the op-amp= ±15V how do we find the input offset voltage?

55. physics

how do i calculate the pressure of a pipe with same area and constant velocity. I tried to use bernoulli's equation but it only applies if the area of the opening and end are not the same

56. math

how is this series 3+ 9/4 +27/16 +81/64... is converge to 12? i represent the series as 3^(n+1)/4^n n starts from 0 to infinity, is this correct formula

57. physics

for both of these object system1: earth and ball if a ball is falling down, is the work done on it positive since force and displacement are in the same direction. system 2: earth and basket a basket is tied to a rope and is dropped then come to a full

58. chemistry

A 50-mL Mohr buret is connected to a 1-ft length of capillary tubing. The buret is then filled with water and the volume of water versus time is monitored as the water gradually flows through the capillary tubing. This process is found to be first-order

59. chemistry

what does it mean by in phase and out of phase for orbitals. Is in phase means that it's bonding and out of phase is antibonding?

From the Standard Potential Table in your general chemistry textbook: Which reaction has been chosen as the 'standard' against which every other reaction is measured? A. 2H+ + 2e–H2 B. Li+ + e–Li C. O2 + 4H+ + 4e–2H2O D. F2 + 2e–2F– E. H2 +

61. chemistry

Why is HF has lower boiling point than CsI, even though HF has hydrogen bond. Does HF have higher boiling point than O2

62. chemistry

by the way, how can you tell if work is 0 for 2 mol of solid iron (C = 25:1 J/(molK)) is heated from 20C to 200C. How much does its internal energy change?

63. chemistry

2 mol of solid iron (C = 25.1 J/(mol K)) is heated from 20C to 200C. How much does its internal energy change? U = q +W but no matter exchange so work is 0. then U=q=9036J But why is q not negative since isnt the system loses its heat to the surrounding

64. chemistry

what if compound has those metalloids(metal near stair case) with gas element, is it going to be semiconductor. Can you think of any other compound with metalloid and gas elements beside SiO2 that is insulator

65. chemistry

for NaTl, is the unit cell of it based on the repetition of body centered cubic and the holes in this unit cell are octahedral? how many of each of the 2 cubes drawn for NaTl are required its unit cell? is it 8?

66. chemistry

A 4.14 m solution of the solute methylene chloride dissolved in the solvent ethanol is available. Calculate the mass ( kg ) of the solution that must be taken to obtain 1487 g of methylene chloride. CH2Cl2-1327 (kg/m^3) C2H5OH-789.3 (kg/m^3)

67. chemistry

You have 2.0 g of solid A, 100.00 mL of water (100.0 g of water), and the total mass of solid A combined with 100.00 mL of water is found to be 102.0 g. The mass percent of A in this solution is

69. science

if i use 30 ul from a total volume of 600ul to get 40ug/ml. So to get the total ug only, do i take 40ug/ml*.030ml*(600ul/30ul)=total ug

70. math

how do i represent 1/(1+x^4) in general taylor polynomial. I know the pattern is 1-x^4+x^8-x^16..... I don't know how to represent this pattern in variables equation form. What i mean by general taylor polynomail is for example 1/(1-x)=1+x+x^2+x^3...+x^n.

71. math

how do i represent 1/(1+x^4) in general taylor polynomial. I know the pattern is 1-x^4+x^8-x^16..... I don't know how to represent this pattern in variables equation form

72. chemistry

If 0.0490 mol of solid Al reacts stoichiometrically according to the balanced equation with 990 mL of aqueous Cl-, what molarity (M) of Cl- is required? 3 CuCl2(aq) + 2 Al(s) → 3 Cu + 2AlCl3(aq)

73. chemistry

please check my answer(one with star). The solubility of borax is directly proportional to temperature. Therefore, the sign of H is A. negative* B. positive C. unknown with the given information since solubility shifts the reaction to the right, therefore

74. chemistry

is Li3As a semiconductor

75. chemistry

did i order the intermolecular forces correctly ion-ion > ion-dipole force > dipole-dipole >ion-induced dipole> dipole-induced dipole> hydrogen bond>dispersion bond

76. chemistry

lets just say that 5g of solid benzoic acid burns under gaseous oxygen atmoshphere. Temperature increases from 20c to 50c. So is this exothermic so the sign is negative? how is it not the same as 2 mol of solid iron (C = 25.1 J/(mol K)) is heated from 20C

77. physics

if velocity vector is changing but speed is constant, can there still be work

78. physics

if a particle has work of 8J and doubles its speed. how much work it has done? Can we still determine work in this problem without mass

79. chemistry

for NaTl, is the unit cell of it based on the repetition of body centered cubic and the holes in this unit cell are octahedral?

80. chemistry

If 6.38 g of a polyethylene glycol is dissolved in 7550 ml of water at 300 oK, the solution has an osmotic pressure of 0.171 torr. Calculate the molar mass (g/mol) of the polyethylene glycol.

1)An increase in temperature ____________ the kinetic energy and average speed of the gas particles. A. decreases B. increases 2)As a result, the pressure on the walls of the container __________. A. decreases B. increases C. is not affected 1) i think its

82. chemistry

Why isn’t the six atom ring created when ASA binds to Fe3+ flat like the benzene ring? is it because that Fe3+ distorted the angles tats why it is not flat

83. chemistry

How do the bond angles in the six atom ring (created when ASA binds to Fe3+) differ from the bond angles of the six atom benzene ring? are there even any tetrahedral angles in here because the angles i found are 123.66,124.12,119.15,114.71,89.86. Some are

84. chemistry

If the ratio of the rate of effusion of an unknown gas to that of CO under the same conditions is 0.7978, calculate the molar mass (g/mol) of the gas

85. ENGLISH higschool

Does knowledge acquired in highschool liberate or hinder studnets?

86. english

What is the difference between poems and poetry?

87. biology

are both ER and secretory vesicles have double bilayer membrane

88. math

how do i represent 1/(1+x^4) in general taylor polynomial. I know the pattern is 1-x^4+x^8-x^16..... I don't know how to represent this pattern in variables equation form

89. math

in a skew symmetric, how do we explain that its diagonal entries has to be all 0 without giving examples to support it

90. engineering

what is the device used called for eye laser surgery and do you know which company use it

91. engineering

what is the device called for eye laser surgery and do you know which company use it

92. chemistry

can you what is G and G knot in terms of spontaneity and chemical equilibrium. I know that G is spontaneous when is negative but what does G knot tell you

93. chemistry

when do we have pka=ph

94. physics

in an adiabatic process from A to B, do A and B have same temperature?

For the cell: C(s) C+(aq) B+(aq) B(s). Metal ______ is the "negative" electrode. is it C(s)

96. math

how do you take log(-63)

97. calculus

when finding area, what does it mean when it says that the function is below by the x-axis, can you give me example of this

98. chemistry(check my work)

The freezing point of a solution is A. lower than the freezing point of the solvent alone because higher temperature is required to accelerate solvent molecular motion enough to overcome obstructon by solute particles.. B. higher than the freezing point of