How many grams of hydrogen are needed to produce 1.80 g of water according to this equation? 2h2 + o2 → 2h2o

Hey there!:

Molar mass:

H2 = 2.01 g/mol    ;    H2O = 18.01

Given the reaction:

2 H2 + O2 = 2 H2O

2 * (2.01 ) g H2 2 * ( 18.01 ) g H2O

mass H2 1.80 g H2O

mass H2 = 1.80 * 2 * 2.01 / 2* 18.01

mass H2 = 7.236 / 36.02

mass H2 = 0.2008 g

Hope that helps!

"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"