Eleven molecules have speeds 15, 16, 17, . . , 25 m/s. calculate (a) vavg, and (b) vrms. part a express your answer with the appropriate units.

The speeds are

15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 m/s.

Vavg =  15 + 16 + 17 + 18 + 19 + 20 +21 +22+ 23+24+ 25 / total molecules = 20 m/s

Vrms = ((sum of square of speed of molecules ) / total molecules )^1/2

Vrms = ( (15^2 + 16^2 + 17^2 + 25^2) / 11 )^1/2

       = (225+ 256 + 289 + 324 + 361+ 400 + 441 + 484 + 529 +576 +625 / 11)^1/2

= (4510 / 11 )^1/2 = 20.25 m  /s

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"

2b2t

explanation:

2b2t