- If the abundance of the first isotope is 68.037%, then the abundance of the second isotope is 100%-68.037%.
Substituting into the atomic mass formula,

Answer:
17.934 kg of water
Explanation:
If balanced equation is not given; this format can come in handy.
For any alkane of the type : CₙH₂ₙ₊₂ , it's combustion reaction will follow:
2CₙH₂ₙ₊₂ + (3n+1) O₂ → (2n)CO₂ + 2(n+1) H₂O
For butane:
2C₄H₁₀(g) + 13O₂(g) → 8CO₂(g) + 10H₂O(l)
2 moles of butane gives 10 moles of water.
1 mol of any substance has Avogadro number(N) of molecules in it( 6.022 x 10²³)
Mass of 1 mole of any substance is equal to it's molar mass
So, if 2 x N molecules of butane gives 10 x 18 g of water.
Then 1.2 x 10²⁶ molecules will give:

= 17.934 x 10³ g of water
= 17.934 kg of water
Answer: The Diver's air tank is filled with oxygen gas.
The filling of air tank while keeping in water can be explained in reference to the Charles' Law.
Charles' Law: It states that the volume of the ideal gas is directly proportional to the absolute temperature at constant pressure.
(at constant Pressure)
The Scuba tank contains cold water and is present at high pressure. The gas which is put in the tank will be compact and would not expand. As the temperature is low inside the tank, hence by using Charles' Law, the volume will also decrease inside the tank.
When the air tank is filled, it is always kept in a tub of water because the pressure is high and hence, more oxygen gas can be filled inside the air tank.
Answer: The amount of water formed is 12 moles
Explanation: Please see the attachments below