Question

20.0g of H2(g) and 32g of O2(g) are reacted produce H2O(l). The amount of hydrogen left behind after completion of reaction is?

Answer 1

Answer:

8 moles = 16 gm of H2 left over

Explanation:

The balanced equation is

2 H2  +  O2   ===> 2 H2 O

20 g H2   =    20 g / 2 gm/mole = 10 moles of H2

32 g O2   =    32g / 32 g / mole = 1 mole O2

From the balanced equation, you can see each 2 moles of H2 requires 1 Mole of O2

  you would need 20 moles of O 2 to react withe the 10 moles of H2

      but you only have 1 mole of O2      so   8 moles of H2 will be left