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Latent Heat Problem/ Phase Change.....Please Help!!!!!!! At 1:00pm you place an ice cube tray in the freezer. Each of the 12 1-gram cubes has a temperature of 20°C. At 1:10 the water temperature has dropped to 12°C. At what time will you have ice? i have been messing around with this problem...
2. Chem Problem

i worked out .05844 mol in 1 kg for NaCL and .11098 mol in 1 kg of CaCl2 is this correct
3. Need help with chem problem

mole fraction= amount (mol) of solute / amount (mol) of solute + amount (mol) of solven mass percent= mass of solute/ mass of solute + mass of solvent x 100 molality = amount mol of solute/ mass kg of solvent i know the equations do i just plug the quantities in or is there more to it...
4. Chem Problem

Thanks yeah i should of picked that up i got that one......can you please help me with one of the others i have posted im strugglin on those
5. Chem Problem

8.46 e11 g does that sound reasonable
6. Chem Problem

I have a total of 3.02 e10 moles he takes in so would i just need to convert that to grams?
7. Chem Problem

I understand how to convert from moles to grams, etc im just not sure how i would take the CO amount then throw in the amount he inhales and how many hours to figure it out.
8. Chem Problem

I am really not sure.....i am pretty new to chemistry and not very good at it, can i get some help
9. Problem i need some help with

I think I understand that but what equations will help me get closer to the solution in each case?
10. Kinematic problem help

What does u represent in these equations and i am having trouble finding time, what steps do I need to find this?
11. Need help with chem problem

Homework Statement A solution is made by disolving 0.40 mol isopropanol (C3H7OH) in 0.70 mol water. (a) What is the mole fraction of isopropanol? (b) What is the mass percent of isopropanol? % (c) What is the molality of isopropanol? m Homework Equations...
12. Chem Problem

Homework Statement Air in a smoky bar contains 4.3 10-6 mol/L of CO. What mass of CO is inhaled by a bartender who respires at a rate of 13 L/min during an 9.0 h shift? in g Homework Equations The Attempt at a Solution Can someone let me know what steps to take with...
13. Chem Problem

Homework Statement "De-icing salt" is used to melt snow and ice on streets. the highway department of a small town is decideing whether to by NaCl or CaCl2 for the job. The town can obtain NaCl for \$0.36/kg. What is the maximum the town should pay for CaCl2 to be cost effective? in kg...
14. Chem problem need help

Chem problem need help.... Homework Statement How would you prepare the following aqueous solutions? (a) 1.10 kg of 0.0515 m ethanol (C2H5OH) from ethanol and water Add___ g C2H5OH to ____ g H2O. (b) 511 g of 15.0 mass % HCl from 35.3 mass % HCl Add___ g of 35.3% HCl to ___ g of...
15. Problem i need some help with

Homework Statement A 200kg weather rocket is loaded with 100 kg of fuel and fired straight up. It accelerates upward at 35.0 m/s^2 for 34.0 s, then runs out of fuel. Ignore any air resistance effects. What is the rocket's maximum altitude? How long is the rocket in the air...
16. Kinematic problem help

OK im just not sure what do with the equations, and what is s representing in these equations?
17. Kinematic problem help

Kinematic problem help!!!! Homework Statement David is driving a steady 31.0 m/s when he passes Tina, who is sitting in her car at rest. Tina begins to accelerate at a steady 2.80 m/s^2 at the instant when David passes. How far does Tina drive before passing David? What is her speed...