[Beachgirl]

1. Is this propperly balanced

1C₇H₁₆ + 11O₂  7CO₂ + 8H₂O

2. IF 34.8g of O₂ are mixed with 34.8g of H₂ AND THE MIXTURE IS IGNTED, WHAT MASS OF WATER IS PRODUCED?

H₂ + O₂ :rarrow:H₂O

34.8g (1MOLE/32G) =1.08MOLES O2

34.8g H2 (1MOLE/2.016g) = 17.26 moles H2

1.08 MOLES O2 (18g h20 / 1mol H20) = 19.44 g WATER

[UG]

1. Is this propperly balanced

1C₇H₁₆ + 11O₂  7CO₂ + 8H₂O

Indeed it is.

2. IF 34.8g of O₂ are mixed with 34.8g of H₂ AND THE MIXTURE IS IGNTED, WHAT MASS OF WATER IS PRODUCED?

H₂ + O₂ :rarrow:H₂O

34.8g (1MOLE/32G) =1.08MOLES O2

34.8g H2 (1MOLE/2.016g) = 17.26 moles H2

1.08 MOLES O2 (18g h20 / 1mol H20) = 19.44 g WATER

I would just add that 34.8g (1MOLE/32G) is actually 1.0875 so if you want to round, it would be 1.09 moles O₂. The rest of your method is correct