How many grams of oxygen are required to produce
9 grams of water at standard conditions?
2 H, + 0, → 2H20
grams

4g

Explanation:

Equation of reaction

2H₂ + O₂ → 2H₂O

Molar mass of O2 = 16g/mol

Molar mass of water = 18g/mol

Number of moles = mass / molar mass

Mass = molar mass × number of moles

Mass of O2 = 1 × 16 = 16g

Mass of H2O = 2 × 18 = 36g

So from equation of reaction,

16g of O2 = 36g of H2O

X of O2 = 9g of H2O

X = (9 × 16) / 36

X = 4g

4g of O2 will produce 9g of H2O

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

i think its 100.

hope this !