An unknown mass of a certain solid, initially at 60⁰C, is heated at a uniform at a uniform rate. After 4.0 min the solid reaches its melting point of 80⁰C, and it remains at that temperature for 3.0 min until

46,278 results
  1. chemistry

    You are analyzing a solid isolated from a reaction and find that its boiling point is over 1000 ∘C. You dissolve the compound in water solution and recrystallize it to produce some solid crystals that you use to determine that the compound is a

  2. chemistry

    A 32.2 g iron rod, initially at 22.3 C, is submerged into an unknown mass of water at 63.9 C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 58.6 C. What is the mass of the water?

  3. AP Chemistry

    (a)calculate the mass percent of carbon in the hydrated form of the solid that has the formula BeC2O4 X 3 H2O (s). I divided 24.02 g by 151.08 g and got .16, or 16%. is that correct? Also, I'm having trouble with this follow up question. When heated to 220

  4. physics

    A uniform metre rule of mass 90g is pivoted at the 40cm mark. If the rule is in equilibrium with an unknown mass m placed at the 10cm mark and a 72g mass at the 70cm mark,determine m.

  5. physics concepts (please check over my work)

    A uniform cyclinder made of lead has the same mass and the same length as a uniform solid cylinder made of wood. The rotatonal inertia of the lead cylinder compared to the wooden one is: I thought at first that the rotational inertia cannot be known or

  6. chem

    suppose you had an unknown solution that contained either dissolved NaOH, NaCl< or NaNO3. you add 4 drops of AgNO3 solution to 4drops of the unknown solution and observed that no solid formed. What can be concluded the unknown solution? why?

  7. chemistry

    Here is the question: A sample of an unknown volatile liquid was injected into a Dumas flask (mflask=27.0928g. Vflask=.104L) and heated until no visible traces of the liquid could be found. The flask and its contents were then rapidly cooled and reweighed

  8. Physics

    A uniform solid cylinder of mass 10 kg can rotate about a frictionless axle through its center. A rope wrapped around the outer radius R1 = 1.0 m exerts a force of magnitude F1 = 5.0 N to the right. A second rope wrapped around another section of radius R2

  9. college chem

    Ammonium carbonate (solid) decomposes when heated to produce three gaseous products - ammonia, water, and carbon dioxide. 1. Write the balanced equation for the reaction. 2. Suppose that ammonium carbonate is heated to 500 K in a sealed vessel. At

  10. chemistry

    When 2.5g of ammonium dichromate is heated, the mass of nitrogen and water vapor released is 1.0g. What is the final mass of the solid product?

  11. Sublimes?

    Question: An unknown compound gave a melting point of 230C. When the molten liquid solidified, the melting point was redetermined and found to be 131C. Give a possible explanation for this discrepancy. My answer: The compound sublimed. How would

  12. Physics

    A uniform solid disk of radius 1.7 m and mass 81.3 kg is free to rotate on a frictionless pivot through a point on its rim. If the disk is released from rest in the position shown by the solid circle, what is the speed of its center of mass when the disk

  13. organic chemistry

    2. An unknown white solid has melting point range 119 – 121o C. Benzoic acid is a white solid of 122 o C melting point. How can a student confirm the identity of the unknown solid (is the benzoic acid or not)

  14. chemistry

    A sample of nickel is heated to 95.0°C and placed in a coffee-cup calorimeter. If the 50.0 g of water in the calorimeter is initially 22.3°C and warms to 25.4°C, what mass of nickel was heated? (The specific heat of nickel is 0.444 J/°C g and water is

  15. physics

    Hello, I have been stuck on this problem. A ball with an unknown mass (mA) is initially 11.9 meters above the surface of a foreign planet. A box with an unknown mass (mE) is initially some distance (hE) above the surface of the Earth. The ball and box both

  16. chemistry

    A sample of solid sulfur is heated with an electrical coil. If 105 joules of energy is added to a 12.4 gram sample initially at 24.4°C, what is the final temperature of the sulfur?

  17. Science Help!

    A student mixed two clear liquids together in a beaker. A solid and a new liquid formed. The student forgot to write down the mass of one of the reactansts. The rest of the data are shown in the table below. Table Mass (g) Liquid reactant A/ unknown Liquid

  18. phy

    (Q1)A gas occupies a certain volume at 27c.If it is heated at constant pressure, its volume is exactly doubled at a temperature of. (a)54c(b)219c(c)327c(d)600c (Q2)If the specific heat capacity of water initially is4.2000/kg/k and the difference in

  19. physics

    A string is wrapped around a uniform disk of mass M = 1.6 kg and radius R = 0.10 m. (Recall that the moment of inertia of a uniform disk is (1/2)MR2.) Attached to the disk are four low-mass rods of radius b = 0.17 m, each with a small mass m = 0.6 kg at

  20. physics

    a ball of mass 0.1kg makes an elastic head on collision with a ball of unknown mass,initially at rest .if the 0.1kg ball rebounded at one third of its original speed, what is the mass of the other ball?

  21. physics

    You create a centripetal force apparatus consisting of a mass m attached to the end of a string and spun in a uniform circular path of radius R, where R = 65.5 cm. The mass is spun in a uniform circular path for 60.0 seconds, during which a total of 117

  22. chemistry

    A sample of nickel is heated to 95.0°C and placed in a coffee-cup calorimeter. If the 50.0 g of water in the calorimeter is initially 22.3°C and warms to 25.4°C, what mass of nickel was heated? (The specific heat of nickel is 0.444 J/°C g and water is

  23. chemistry

    CaCO3 = CaO +CO2 after a 15.8g sample of calcium carbonate was heated in an open container to cause decompostition the mass of the remaining solid was determined to be 9.10g. calculate the mass of carbon dioxide produced.

  24. Physics

    A uniform metre rule of mass 90g is pivoted at the 40cm mark. If the rule is in equilibrum with an unknown mass, M placed at the 10cm mark and 72g mass at the 70cm mark, determine M. Please help me urgently!!

  25. Chemistry

    Consider the hypothetical reaction: A + B + heat ⇌ C + D (All species are in the gaseous phase) What will happen to the concentration of A, B, C, and D under each of the following conditions? a) A catalyst is added to the system, which is at equilibrium

  26. Chemistry

    A 32.3 g iron rod, initially at 22.4 ∘C, is submerged into an unknown mass of water at 62.9 ∘C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 59.4 ∘C.

  27. Physics

    An unknown mass is suspended by a string from one end of an uniform stick which has a mass of 120 g. In order to balance the stick, it must be supported one third of its length away from the mass. the unknown mass is therefore?

  28. chem

    Ammonium carbonate (solid) decomposes when heated to produce three gaseous products - ammonia, water, and carbon dioxide. 1. Write the balanced equation for the reaction. 2. Suppose that ammonium carbonate is heated to 500 K in a sealed vessel. At

  29. Chemistry

    A rectangular solid of unknown density is 6cm long, 3cm high, and 7cm wide. The mass of this solid is 250g. Calculate the density.

  30. Chemistry

    I'm doing a flame testing lab in which I'm supposed to be able to identify an unknown element by observing the color it emits once heated. The color of the flame after heating this unknown metal is a light pinkish-violet. The question I need to answer asks

  31. Chemistry

    I there, this is my lab worksheet, I am having trouble filling it out. Please help me with it. Expt #1- Molecular Weight of Unknown Acid Unknown Acid: #3 Mass of Unknown solid acid transferred:1.0g Volume of volumetric flask: 100.00 mL Concentration of

  32. Physics

    A uniform disk of radius 0.485 m and unknown mass is constrained to rotate about a perpendicular axis through its center. A ring with same mass as the disk\'s is attached around the disk\'s rim. A tangential force of 0.247 N applied at the rim causes an

  33. PHYSICS

    block 3M slides downward without friction. The string connecting blocks 3M and M is ideal (that is, its mass can be neglected and it is not stretchable). The pulley, a uniform solid disc of mass M and radius r , rotates without slipping. Find the

  34. AP Physics Springs - very confusing question

    This is part of a lab with a mass attached to a spring, and the mass attached is of unknown weight. Which of the following can you measure to find one of the unknown masses? You can select more than one. a) the distance the mass stretches the spring b) the

  35. physics-density

    A solid right circular cone of uniform mass density is initially at rest above a body of water, so that its vertex is just touching the water's surface with its axis of symmetry along the vertical. Now, the cone falls into the water, and has zero speed at

  36. chemistry

    When heated, CaCO3 decomposes as follows: CaCO3 (s) = CO2 (g) +CaO (s) in an experiment, 10.00 g of CaCO3 was placed in a .500 L container, and when it was heated to a constant temperature, 50% of the solid decomposed. What is the value of Kc for this

  37. Physics

    An unknown mass of a certain solid, initially at 60⁰C, is heated at a uniform at a uniform rate. After 4.0 min the solid reaches its melting point of 80⁰C, and it remains at that temperature for 3.0 min until completely melted. After a further 6.0 min

  38. physics

    An unknown mass of a certain solid, initially at 60⁰C, is heated at a uniform at a uniform rate. After 4.0 min the solid reaches its melting point of 80⁰C, and it remains at that temperature for 3.0 min until completely melted. After a further 6.0 min

  39. Chemistry- Please Help!!

    Calculate the molar mass of an unknown molecular compound mixed with solid camphor C10H16O, heated and then cooled giving the following data. show all steps in calculation. mass of unknown: 0.195 g Tf(camphor)= 179.8 degree C Kf(camphor)=-40.0 degree C/m

  40. Chemsitry

    Calculate the molar mass of an unknown molecular compound mixed with solid camphor C10H16O, heated and then cooled giving the following data. show all steps in calculation. mass of unknown: 0.195 g Tf(camphor)= 179.8 degree C Kf(camphor)=-40.0 degree C/m

  41. physics

    A sample of lead with a mass of 1.45kg is heated until it reaches its melting point at 330C. The lead is then heated further until it has entirely melted. During this process the lead absorbs a total of 4.46 104J as heat. What is the temperature at which

  42. Chemistry

    Freezing point of pure water = -2, Freezing point of Unknown solution = -1 Mass of unknown in 50g of water = 1.9964g. Calculate the delta T for the solution of the unknown solid and determine the molecular weight of the unknown solid.

  43. Chemistry

    A 0.750 g sample of an unknown solid is dissolved in 100 mL of water and acidfied with 25 mL of 3 M H2SO4 then titrated with a 0.0200 M KMnO4 solution. If the unknown solid requires 12.5 mL of the KMnO4 solution to reach the endpoint, what is the % sodium

  44. Chemistry

    How would the calculation percent of oxalate of the unknown affected when weighting out the unknown solid the actual mass is .758 grams however the mass is mistakenly recorded as .785 grams

  45. Chemistry

    5.00g of an unknown solid was heated to 99.7 degrees C and placed in a calorimeter with 1.25L H20. The initial temp of the water was 25.0 degrees C. During the experiment, the temperature of the water rose to 63.5 degrees C. what is the specific heat of

  46. Chemistry

    A 108g piece of unknown metal is heated to 100 degrees C in boiling water. The heated sample of metal is then dropped into 50ml of H20, which is initially at 23.0 degrees C. After a few minutes the temp. of water raises to 37.5 degrees C. What is the

  47. Physics

    A uniform solid sphere of mass 4kg and diameter 20cm initally at rest, begins to roll without slipping under the influece of gravity, down an incline that makes an angle of 15degrees to the horizontal 1 calculate the angular acceleration of the sphere 2

  48. Chemistry

    A solid nonelectrolyte with a mass of 11.32g is dissolved in 115.00g of water. The observed freezing point of the solution is-3.44 degrees C. Given Kf of water=1.86 degrees C/m, what is the molar mass of the unknown solid?

  49. chem

    given the mass of the original sample and the mass of the solid chloride produced, how do you calculate the mass of the matal in the unknown?

  50. Physics

    Lead pellets of total mass 0.46 kg are heated to 107 C and then placed in a well-insulated aluminum cup of mass 0.15 kg that contains 0.52 kg of water initially at 13.8 C. What is the equilibrium temperature of the mixture?

  51. Physics

    Lead pellets of total mass 0.46 kg are heated to 107 C and then placed in a well-insulated aluminum cup of mass 0.15 kg that contains 0.52 kg of water initially at 13.8 C. What is the equilibrium temperature of the mixture?

  52. chemistry

    Ariel found the density of an unknown solid to be 24.3 g/cm3. Her teacher told her that something must have gone wrong with her measurements because her percent error was 30.0% too high. What was the actual or accepted density of her unknown solid?

  53. Chemistry

    I wanted to calculate the average equivalent weight of an unknown acid for an acid-base titration experiment. The mass of the unknown that I had to obtain is 0.2 g and the equivalents of the acid is .001046 L x N. But is this equation right? Does the

  54. physics

    An unknown material has a normal melting/freezing point of -20.4 °C, and the liquid phase has a specific heat capacity of 179 J/(kg C°). One-tenth of a kilogram of the solid at -20.4 °C is put into a 0.130-kg aluminum calorimeter cup that contains 0.198

  55. chemistry help

    a 3.54 grams solid sample of an unknown monoprotic acid was dissolved in distilled water to produce a 47.0 mL solution at 25 degrees. This solution was then titrated with 0.2 M NaOH. The equivalence point was reached when 35.72 mL of 0.2 M NaOH was

  56. chemistry

    a 3.54 grams solid sample of an unknown monoprotic acid was dissolved in distilled water to produce a 47.0 mL solution at 25 degrees. This solution was then titrated with 0.2 M NaOH. The equivalence point was reached when 35.72 mL of 0.2 M NaOH was

  57. chemistry

    Dissolve 1.5g of an unknown salt into 37g of water and find that the new vapor pressure at 75C is 277 torr. What is the Molar Mass of the unknown? How many grams of the unknown would have to be used in 100ml of water to make a 11.5% solution by mass of the

  58. chemistry

    what happens when solids, liquids, and gases are heated/cooled? Most expand if heated; contract if cooled. Solids, if heated high enough will melt and the liquid may occupy less volume than the solid. Likewise, liquids, if heated high enough, will boil and

  59. Chemistry - Final Temperature

    An unknown mass of each of the following substances, initially at 23.0C, absorbs 1910 J of heat. The final temperature is recorded as indicated. Find the mass of each substance. sand (Tf=62.0C) ethanol (Tf=44.1C) water (Tf=32.1C)

  60. Physics

    A uniform solid cylinder of mass M = 6 kg is rolling without slipping along a horizontal surface. The velocity of its center of mass is 27.6 m/s. Calculate its energy

  61. chemistry

    If 10.0 g of CaCO3(s) is heated, 5.61 grams of solid CaO will remain (4.39 g CO2 gas is driven off) If 3.25 g of NaCl(s), which does not undergo decomposition, is mixed with 5.30 g of CaCO3(s) and the mixture is heated long enough to decompose all of the

  62. PHYSICS

    Calculate the angular momentum of a solid uniform sphere with a radius of 0.120m and a mass of 14.5kg if it is rotating at 6.15rad/s about an axis through its center. Part B Calculate kinetic energy of a solid uniform sphere with a radius of 0.120m and a

  63. Physics 2

    An unknown substance has a mass of 0.125 kg and an initial temperature of 98.0°C. The substance is then dropped into a calorimeter made of aluminum containing 0.285 kg of water initially at 30.0°C. The mass of the aluminum container is 0.150 kg, and the

  64. chemistry

    ensity of Unknown Liquid: Lacy obtained a dry empty flask with a stopper and placed it on an analytical balance. She found the mass to be 36.765 g. Lacy then completely filled the flask with distilled water and forced all the air out with the stopper. She

  65. Physics

    A uniform solid cylinder of mass M = 2 kg is rolling without slipping along a horizontal surface. The velocity of its center of mass is 27.6 m/s. Calculate its energy. I got 761.76 Joules but I think it's wrong.

  66. Chemistry

    An unknown metal has a mass of 4.67g. It is heated to 95.1 C and then placed in a calorimeter that contains 24.3g of water at 21.7 C. The metal and water both reach a final temperature of 24.6 C. What is the specific heat of this metal? What is the unknown

  67. Science

    "A student mixed two clear liquids together in a beaker. A solid and new liquid formed. The student forgot to write down the mass of one of the reactants. The rest of the data is shown in the table below." The data (mass, in grams): Liquid reactant A:

  68. chemistry

    In standardizing a potassium hydroxide solution, a student finds that 32.60mL of the base solution is needed to titrate 0.5045 grams of KHP to a phenolphthalein end point. In another titration, 26.63mL of this same base solution is needed to titrate

  69. Chemistry

    A 35.0-g iron rod, initially at 25.6°C, is submerged into an unknown mass of water at 67.7°C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 63.5°C. What is the mass of the water?

  70. Physics

    (b) Given that Icm = ½MR2 for a uniform solid wheel, (i) show that the rotational kinetic energy is half the translational kinetic energy for such a wheel. (ii) For the wheel of diameter 10 cm, find its final speed after traversing a distance of 10 m down

  71. physics

    A planet with mass 5.37×1024kg and radius 6.51×106m orbits its sun, a distance 141.68×109m away, in a uniform circular motion w/ velocity 3.3×104m/s. Assuming the planet is a uniform solid sphere spinning on its axis and has the same length of day as

  72. Chemistry

    Suppose you had an unknown solution that contained either dissolved NaCL, or NaNO3. You added AgNO3 to the unknown solution and observed that no solid forms. What can be concluded about the unknown solution? (use the solubility rules

  73. Chemistry

    Suppose you had an unknown solution that contained either dissolved NaCL, or NaNO3. You added AgNO3 to the unknown solution and observed that no solid forms. What can be concluded about the unknown solution? (use the solubility rules

  74. Chemistry

    Mass of unknown solution=25.671 Mass ethanol =8.243 Assuming that prior experiments have shown the single-step extraction removes only 72.0 % of the ethanol, the mass of ethanol in your original unknown is 11.45 Mass percent ethanol =44.6 % Given a density

  75. Physics

    A uniform wooden metre rule of mass 90g is pivoted at the 40cm mark.if the rule is in equilibrium with an unknown mass M placed at the 10cm mark and 72g mass at the 70cm mark ,determine M.(WAEC 2000)

  76. Physics I Newton's 2nd Law

    I need help! I cannot seem to figure out what I will need to do for my final tomorrow. I will be given a mass of a glider and an acceleration. Another mass (my unknown) will be tied to a string to the glider and will graphically give me my acceleration.

  77. Chemistry

    What mass of copper solid, initially at 25oC,should be added to 100 g of steam, initially at100oC, if we want exactly half of the steam to condense? The specific heat of copper is 0.385 J g-1 oC-1. For water, the heat of vaporization is 2257 J g−1.

  78. Chem

    Using the standardized NaOH solution, the student weighs out 0.2550g of a solid unknown acid and finds that 28.50mL of the NaOH solution is required to reach an end point with the acid. Calculate the molar mass of the unknown acid, assuming the acid is

  79. Chem

    Using the standardized NaOH solution, the student weighs out 0.2550g of a solid unknown acid and finds that 28.50mL of the NaOH solution is required to reach an end point with the acid. Calculate the molar mass of the unknown acid, assuming the acid is

  80. Chemistry

    Assume that a reaction occurs in which unknown substances R and S react to form unknown substances T and U. From the information below, determine the mass of substance T that will be formed if 45.0 grams of substance R reacts with 23.0 grams of substance

  81. AP CHEMISTRY

    The molar mass of an unknown organic liquid (M~100) is determined by placing 5 mL of the liquid in a weighed 125-mL conical flask fitted with a piece of Al foil with a pin hole in it. The flask is heated in a boiling water bath until the liquid evaporates

  82. Physics Urgent

    A container of volume V = 103 cm3 has a mass of 30.0042 g when evacuated. When the container is filed with an unknown gas of pressure p = 4.72 atm at temperature T = 20oC, the mass of the system increases to 30.9508 g. Assuming that the unknown gas behaves

  83. Physics Urgent

    A container of volume V = 103 cm3 has a mass of 30.0042 g when evacuated. When the container is filed with an unknown gas of pressure p = 4.72 atm at temperature T = 20oC, the mass of the system increases to 30.9508 g. Assuming that the unknown gas behaves

  84. Physics

    A mass M of solid metal at temperature T is put into 3.0kg of water which is initially at 90◦C. The metal and water are placed in an insulated container. The specific heat for water is 4186 J kg K . The metal has a melting point of 60◦C. The latent

  85. Chemistry

    Since the unkown acid is monoprotic, this also equals the number of moles of acid to use. A typical molar mass for an unknown acid in this experiment is 380 g/mol. Using this molar mass, calculate the mass (in grams) of unknown acid you should use per

  86. chemistry

    A sample of 10.00g of a solid unknown was dissolved in 25.00g of water. Assuming that pure water freezes at 0.0°C and the solution freezes at -5.58°C, what is the molal concentration of the solution? What is the molar mass of the solid? Show your

  87. physics

    . 0.30m ....|______|_________________________ ....|...../\ ...|_|

  88. Chemistry

    A solid sample of a hydrate salt, NaNO3xH2O, was heated gently to drive off all the water of crystallization. Starting with a mass of 7.494g of NaNO3xH2O, a mass of 5.263g of the anhydrous salt, NaNO3 was obtained. Determine the value of x (which is

  89. chemistry

    to find the molarity of an aqueous solution of an ionic solid what do you need to know? a... mass of solid, formula of solid, volume of water b...moles of solid, formula of solid, volume of water c....mass of solid, formula of solid, volume of solution

  90. Chemistry

    When an unknown substance weighing 2.386g is heated for 5 minutes and cooled to room temperature, it's new weight is 3.183g. No smoke rose for the sample while it was heated and it turned from white to a slight yellow. Were the students performing this

  91. Physics

    A 4.0 g bullet is shot with an initial velocity of 300.0 m/s into a board (I = 19.0 kg m2). The board is held still by a frictionless pivot a third away from its bottom end, as shown below. Assume that you can treat the board as a uniform rod. 1) What is

  92. physics

    A 2.0 g bullet is shot with an initial velocity of 200.0 m/s into a board (I = 12.0 kg m2). The board is held still by a frictionless pivot a third away from its bottom end, as shown below. Assume that you can treat the board as a uniform rod. 1. What is

  93. physics

    A uniform metre rule of mass 90g is pivoted at the 40cm mark. If the rule is in equilibrium with an unknown mass market placed at the 10cm mark and a 72g at the 70cm mark,determine m.

  94. Maths

    A uniform metre rule of mass 90g is pivoted at the 40cm mark.if the rule is in equilibrium with an unknown mass m placed at the 10cm mark and a 72 g at the 70cm mark,determine m.?

  95. physics

    A solid right circular cone of uniform mass density is initially at rest above a body of water so that its vertex is just touching the waters surface with its axis of symmetry along the vertical. Now, the cone falls into the water, and has zero speed at

  96. Physics

    A solid right circular cone of uniform mass density is initially at rest above a body of water, so that its vertex is just touching the water's surface with its axis of symmetry along the vertical. Now, the cone falls into the water, and has zero speed at

  97. physics

    A 75.00-g sample of an unknown metal is heated to 52.00°C. It is then placed in a coffee cup calorimeter filled with water. The calorimeter and the water inside have a combined mass of 225.0 g and an overall specific heat of 2.045 J/(gi°C). The initial

  98. Chemistry

    It takes 32 seconds for a certain number of moles of H2 to effuse through a leak in a tank. An unknown gas was later places under the same conditions; it took 1:39 for the same number of moles to effuse. Find the molecular mass of the gas. I set it up like

  99. physics

    A uniform solid cylinder of mass 1kg rolls with out slipping on aflate surface at aspeed of pay/200rad/s how long will it be when they meet?

  100. Chemistry

    Include an explanation, balanced chemical equation, units, significant figures and/or calculations where appropriate. Determination of the Molar Mass of an Unknown Acid Trial 1: 0.499 g unknown acid 24.07 mL NaOH Trial 2: 0.501 g unknown acid 23.71 mL NaOH

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