Recent content by Spartan Erik

Homework Statement The half-life of an isotope of phosphorus is 14 days. If sample contains 2.9 × 10^16 decays such nuclei, determine its activity. Answer in units of Ci. Homework Equations / The Attempt at a Solution I know that one Ci is equal to 3.7*10^10 bq (or decay per second), I'm...

Ah I just realized that I was calculating the DECREASE in temperature of hot water, so a negative decrease is a positive value. Thanks!

Homework Statement I'm doing calorimetry, and I have 34.73C and 63C. I need to subtract 63 from 34.73, and get the answer in Kelvin. Homework Equations The Attempt at a Solution I know you add 273 to Celsius values to get Kelvin, but I am not sure which of these methods is correct: 1...

Homework Statement Homework Equations FeC2O4 x 2H2O + H2C2O4 + H2O2 + K2C2O4 --> K3[Fe(C2O4)3] x 3H2O The Attempt at a Solution Got it! Nevermind! Solution for future reference: 2||FeC2O4 x 2H2O|| + H2C2O4 + H2O2 + 3||K2C2O4|| --> 2||K3[Fe(C2O4)3] x 3H2O||

Thanks!

Oh so to account for total volume it must be 0.012093g of Fe(NO3)3 / 100 mL H2O? So therefore, 0.00012093g of Fe(NO3)3/mL of H2O, which is the same as 0.12093g of Fe(NO3)3/L of H2O Molar mass of Fe(NO3)3 is.. 241.8602 g/mol, so: 0.12093g Fe(NO3)3 / L x 1 mol / 241.8602g = 0.0004999 mol / L...

Homework Statement "A scientist prepares 100 mL of an iron (III) nitrate solution by weighing out 4.8372 grams of the solid iron (III) nitrate and dissolving it in deionized water using a 100 mL volumetric flask. She then pipettes 5 mL of that solution into a 20 mL volumetric flask and...

Homework Statement A microscopic scientist is assembling sugar molecules (C6H12O6) from C, H, and O atoms. If he has 6.022x10^23 atoms of each type, how many grams of sugar molecules can he assemble? Which type of atom does he run out of first? Homework Equations 1 mol = 6.02x10^23 atoms 1...

http://en.wikipedia.org/wiki/Solubility_chart Yes that is correct.

Homework Statement A 2.0 kg mass is attached to one end of an ideal spring with a spring constant of 500 N/m and a 4.0 kg mass is attached to the other end. The masses are placed on a horizontal frictionless surface and the spring is compressed 10 cm from its equilibrium length. The spring...

Homework Statement Two astronauts are initially floating together with zero speed in a gravity-free region of space. The mass of Major Jones is 90 kg and that of Captain Smith is 70 kg. Major Jones pushes Captain Smith away so that Captain Smith attains a speed of 0.4 m/s. The recoil speed...

Homework Statement A 10-kg cart starts up an incline with a speed of 2 m/s and comes to rest 2.5 m up the incline. The total work done on the cart is: -20J, -12J, 12J, 20J, Impossible to calculate Homework Equations W = Fd W = Fdcos(theta) The Attempt at a Solution I'm not...

Homework Statement An ideal spring is hung vertically from the ceiling. When a 3.0 kg mass hangs at rest from it the spring is extended 9.0 cm from its relaxed length. An upward external force is then applied to the block to move it upward a distance of 12 cm. While the block is being moved...

Well the 75N is due to gravity, so the mass is 7.653kg Breaking it into horizontal and vertical components: mgsin(theta) = 7.653x9.8xsin(30) = 37.5 mgcos(theta) = 7.653x9.8xcos(30) = 64.951 If the object is accelerating upward at 0.5 m/s^2 and the mass is 7.653kg, then the force is 3.826N

Homework Statement A man pushes a create which weighs 75 N upward along a frictionless slope that makes an angle of 30° with the horizontal. The force he exerts is parallel to the slope. If the speed of the crate increases at a rate of 0.5m/s^2, then the work done by the man while moving the...