Answer:

Explanation:
The integrated rate law for radioactive decay is

1. Calculate the decay constant

2. Calculate the half-life

17) 8.4 / 20 x 100
18) 20 . 0.5150
19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
PH + pOH = 14
12.52 + pOH = 14
pOH = 14 - 12.52
pOH = 1.48
[OH⁻] = 10^ -pOH
[OH⁻] = 10 ^- 1.48
[OH⁻] = 0.033 M
Answer:
56.28 g
Explanation:
First change the grams of oxygen to moles.
(50.00 g)/(32.00 g/mol) = 1.5625 mol O₂
You have to use stoichiometry for the next part. Looking at the equation, you can see that for every 2 moles of H₂O, 1 mole of O₂ is produced. Convert from moles of O₂ to moles of H₂O using this relation.
(1.5625 mol O₂) × (2 mol H₂O/1 mol O₂) = 3.125 mol H₂O
Now convert moles of H₂O to grams.
(3.125 mol) × (18.01 g/mol) = 56.28125 g
Convert to significant figures.
56.28125 ≈ 56.28