Chemistry Brooks Homework

FINISH THESE FOR HOMEWORK

I WOULD PRINT THIS OFF SO YOU CAN HAVE THEM TO USE FOR THE WEEKEND.

NOTES

NOTES MOLE……

January 27, 2012

1 mole = molar mass

1 mole = 6.022 x 10²³ units( formula units)/atoms (element)/molecules (covalent compound)

1mole = 22.4 L of a as at STP                  Gases can change

STP= 1 atm pres and 273K

1 mole = 24.1 of a gas at 220C and 1 atm.

****** Remember that an empirical formula as well as a molecular formula are a ratio of the moles of each element in the compound******

Think of the mole as a hub…. Many things can convert into a mole.

   1 Mole              =     molar mass (g)            

Molar mass (g)                 1 mole

6.022 x 10²³ molecules     =             1 mole

           1 mole                          6.022 x 10²³ molecules       

22.4 L of Gas     =        1 mole gas

     1 mole                    22.4 L of Gas             

1.     What is the mass of .450 moles of HCL?

4.50 mol HCL         36.46 g HCL   = 16.407 = 16.4g HCL

                                                1 mil HCL

2.     How many moles of KNO3 will have a mass of 19.6 grams?

(If you see the terms grams or mass… you need to know the molar mass)

19.6g KNO₃          1 mol KNO₃       =       .1938 mol

                             101.11g KNO₃

K = 39.10                                           

N  = 14.01

O3 = 48.00

        101.11

For every one mole of anything… will be its molar mass in (grams)

3 parts to the correct answer:

1.     Numbers

2.     Units

3.     Substance we are dealing with