Recent content by John Ker

  1. J

    Calculating the frequency of an electron orbiting in a magnetic field

    So my thought process is as follows, since the initial centripetal force and the second magnetic force are working together, we can set up an equation to calculating final frequency. However, I am struggling with how this can be done given so little numbers. mvi^2/r + qvB = mv^2/r Am I on the...
  2. J

    Coulomb's Law and 4 point charges

    ahh thank you! That makes a lot more sense and I just got the answer.
  3. J

    Coulomb's Law and 4 point charges

    It is not, but didn't I correctly account for that with my calculations? 2 ( k *(6.5 * 6.5)/(.029^2)) + k(6.5*6.5)/(.04101)^2 The equation after the addition sign I utilize Pythagoras to account for the extended distance. Is this what you mean?
  4. J

    Coulomb's Law and 4 point charges

    A charge Q is placed at the centre of the square of side 2.90 cm, at the corners of which four identical charges q = 6.5 C are placed. Find the value of the charge Q so that the whole system is in equilibrium. Can someone help me figure out where I have went wrong, I began by finding the force...
  5. J

    Synthesis of Coordination Compounds and the Role of Charcoal

    Homework Statement I performed a lab that has the main objective of reacting a cobalt(II) chloride solution through a series of steps to achieve the following two compounds: Compound A - Purple - [Co(NH3)5Cl]Cl2 Compound B - Orange - [Co(NH3)6]Cl3 The only difference when performing the...
  6. J

    Chemistry lab - limiting reagent - Can someone verify?

    Hello, thanks for the response. So after taking a relook youre right, I overlooked the product being the limiting reagent. In that case, wouldn't CuO be the limiting reagent, since it is only .004moles. CuO is .004 7M H2SO4 is .035M 1M H2SO4 is .005M In both cases, even with a reduction in...
  7. J

    Chemistry lab - limiting reagent - Can someone verify?

    Homework Statement Suppose that, for reaction 4, you could not find the bottle of 7 M H2SO4 so you added 5.00 mL of the 1.00 M H2SO4 instead. How would this impact your final yield of Copper. (Show with calculations how this would impact the limiting reagent.) Homework Equations CuO(s) +...
  8. J

    Magnesium Carbonates Reaction Under Various Test?

    Homework Statement If you had a solution of Magnesium carbonate, what results would you expect from the following four tests: Precipitation Test, Flame Test, Benedicts Reagents Test, Dilute Acid Test. Could someone take a look at my reasoning to how the Magnesium Carbonate would react under...
  9. J

    Final Temperature of Copper and Water in Insulated Vessel

    SO the fomula would become: 529 * .387 (Tf - 89.5) = 159 * 4.18 * (Tf - 22.8) + 10(Tf - 22.8) Where I then distribute everything out and solve for Tf? Are the signs correct on both sides, I recall seeing that one side needs to be negative, but I am not sure that is relavent here.
  10. J

    Final Temperature of Copper and Water in Insulated Vessel

    Homework Statement A 529 g piece of copper tubing is heated to 89.5°C and placed in an insulated vessel containing 159 g of water at 22.8°C. Assuming no loss of water and a heat capacity for the vessel of 10.0 J/°C, what is the final temperature of the system [c of copper = 0.387 J/g · K]...
  11. J

    Lab Report Help -- total amount of CaCO3 in an unknown antacid tablet

    Thanks for the reply. Since the average atmospheric pressure around the flask was ~101 kpa, that means a small leak would gradually increase the pressure to that amount, therefore increasing amount of apparent CaCO3 present. However, could you confirm my theory about the last part of the...
  12. J

    Lab Report Help -- total amount of CaCO3 in an unknown antacid tablet

    The amount of CaCO3 was calculated using the formula: mCaCO3 = nCaCO3 * MWCaCO3 / %purity Where MW is molecular weight. nCO2 was found using Pf / Tf - Pi / Ti * V/r nCaCO3 = nCO2 So yes, since finding the amount relies on pressure, it would affect it. I am just not sure how a leak would...
  13. J

    Lab Report Help -- total amount of CaCO3 in an unknown antacid tablet

    Homework Statement Hello, I am currently attempting to complete a lab report involving the calculation of the total amount of CaCO3 in an unknown antacid tablet. This was done by calculating the pressure inside a flask before the reaction, then relating it to the pressure after the reaction...
  14. J

    Travelling towards a Canyon Wall: Calculating Beat Frequency

    Ohh, so the hint in the question is not referring to 2 separate doppler effects, rather 2 doppler effects on the same wave that beats with the initial source. Sooo... EQN 1: Source moving towards observer: f_1 = 440 [ 1 / (1 - 8.33... / 340) = 429.47 Hz EQN 2: Observer moving...
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