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An 0.6600 mol sample of an ionic compound has a mass of 131.9 g. Determine the mass (g) of one formula unit of the compound. I have no idea how to do the problem. I need help please, I'm reviewing for an exam. Thank You!

15 years ago

If a sample of BaSO3 is found to contain 1.73 · 1018 SO32- ions how many moles of Ba2+ ions are present? Express your answer in scientific notation. The following information is given: Molar Mass (g/mol) BaSO3 217.39 Ba2+ ion 137.33 SO32- ion 80.063 Avoga...

15 years ago

Which molecule based on the following enthalpies is the most stable? Molecule A: -70 kJ/mol Molecule B: 100 kJ/mol Molecule C: 145 kJ/mol Is it Molecule A? Isn't the lower the enthalpy the more stable the molecule? Thank You

15 years ago

Are 5s and 5p considered to be degenerate orbitals? I know degenerate orbitals mean that they have the same energy but different spatial arrangement.

15 years ago

Two identical objects each hold a net charge of q = 8e. If the gravitational force between the two objects exactly cancels the electrostatic force between the objects, what is the mass of each object? Where G: 6.67E-11 Ke=8.99E9 I know the equation is m=s...

15 years ago

Consider three charged particles placed along the x-axis. The particle with q1 = 9.27 nC is at x = 7.66 m and q2 = 4.82 nC is at x = 2.64 m. Where must a positive charge, q3, be placed such that the resultant force on it is zero? I know F3= F13+ F23 (net...

15 years ago

If a cube with edges of 1.000 cm weighs 25.68 g, what would the mass of a cube of the same material with sides 2.66 cm in length be? I got 68.301 but it was wrong... i basically made a ratio 25.68 g/1cm and did 2.66cm x 25.68 (dimensional analysis) This s...

15 years ago

Whats the name for HI(aq)? I thought it was Hydrogen Iodide, but that's incorrect, does the aq change the name?

15 years ago

131.9 g * (0.66mol)/(6.022*10^23) =1.4455*10^(-22)formula unit I don't think that's right....

15 years ago

I get 199.848 but I'm pretty sure its suppose to be a small number... Here's a similar problem that I have the answer to but I don't know how to do... An 0.4200 mol sample of a metal has a mass of 9.656 g. Determine the mass (g) of one atom of the element...

15 years ago

oh i got it!! (9.656/0.4200)/(6.022E-23)= 3.810E-23 so I do the same thing for the other problem! Thank you for you help :)

15 years ago

Oh I see...I was making it complicated So if the ratio wasn't 1 to 1 like in the following.. Na2SO3 is found to contain 2.37 · 10-3 mol of Na+ ions then I would have to use dimensional analysis to solve?

15 years ago

hmm okay. So when do you know if your suppose to divide by Avogadro's number as you did in the first problem or multiply by the ratio as you just did?

15 years ago

Is it because in the first problem they gave you ions and in the second they gave you moles?

15 years ago

Thank you for you help. I appreciate it!

15 years ago

You have to make an equation and plug in the information based off what you are given. Perimeter= 2(W)+2(L) [1st equation] and they told us the Length= 29+w [2nd equation] so plug that into the first equation P=2W+2(29+W) 150=2W+2(29+W) solve for W(width)...

15 years ago

c. use kinematics equation y=vi*t+1/2at^2 vi= 0 (because rock was dropped) a=-9.8m/s^2 t= 4s (time given) plug in and you get your height a. use kinematics equation vf^2=vi^2+2ay vi=0 (rock dropped) a=-9.8 y= (whatever you got from part c) plug in and sol...

15 years ago

First need to convert km/hr to meters/second (I got around 3333.33 m/s but you might want to double check that) so 3333.33 is your initial velocity v_i using kinematics equation: v_f=V_i+at y=v_i*t+(1/2)at^(2) the highest point the projectile reaches is w...

15 years ago

Oh, you mean the 'e' in the 8e might stand for 8 times electron charge of 1.60217646E-19 coulombs? I was doing it as 8 times e(the mathematical constant 2.71828183)

15 years ago

That's interesting...because the altitude is so high you have to deal with escape velocity instead of the usual kinematics.

15 years ago

Thank you! I should have known that, guess its getting late :)

15 years ago

Thank You!

15 years ago

What are you trying to solve for?

15 years ago

26,320 got it using a calculator

15 years ago

Doing chem lab hw too huh? 1.60x 10^-5 M * 0.1 L / 1.54E-04 M = L convert to mL

15 years ago