An electrochemical cell is composed of pure copper and pure lead electrodes immersed in solutions of their respective divalent ions. for a 0.8 m concentration of cu2+, the lead electrode is oxidized yielding a cell potential of 0.500 v. calculate the concentration of pb2+ ions if the temperature is 25˚c. the standard potentials for cu and pb are +0.340 v and -0.126 v.

"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"

you need to stop taking that class

the pseudoscience are like beliefs, theories, or like practices that are considered scientific