Remember pH=-log(H ions). So it would be pH=-log(10^-7).
The Balanced chemical equation of reaction of Borane with oxygen is as follow,
B₂H₆ + 3O₂ -----> 2HBO₂ + 2H₂O
According to this equation 27.66 g (1 mole) of B₂H₆ reacts with oxygen to produce 36 g (2 moles) of water.
The amount of water produced when 19.2 g of B₂H₆ reacted is calculated as follow,

=

Solving for x,
x = (36 g of H₂O ₓ 19.2 g of H₂B₆) / 27.66 g of B₂H₆
x =
24.98 g of H₂O
Result:
24.98 g of water is produced when 19.2 g of B₂H₆ is reacted with excess of oxygen.
Answer:
neither accurate nor precise
Explanation:
Accuracy is the ability to give the same result on different measurements made under the same conditions or to give the desired result accurately, therefore, as observed in the image, the results are not accurate, since they are all different.
They are not precise either, since the precision is the degree of agreement between the independent results of a measurement, obtained under stipulated conditions, be it repeatability, reproducibility or intermediate.
Explanation:
The solubility curve helps us to compare the solubility of difference substances at same temperature. It gives the idea that solubility changes with the temperature. The solubility curve helps us to predict which substance will crystalize out first from hot solution containing two or more solutes.