<span>lower than the boiling point of water
</span>
The question is incomplete, complete question is ;
A deep-sea diver uses a gas cylinder with a volume of 10.0 L and a content of 51.8 g of
and 33.1 g of He. Calculate the partial pressure of each gas and the total pressure if the temperature of the gas is 21°C.Express the pressures in atmospheres to three significant digits separated by commas.
Answer:
Partial pressure of the oxygen gas is 3.91 atm.
Partial pressure of the helium gas is 20.0 atm
Total pressure of the gases is 24.0 atm
Explanation:
Moles of oxygen gas = 
Moles of helium gas = 
Total moles of gas = 
Volume of the cylinder = V = 10.0 L
Total pressure in the cylinder = P = ?
Temperature of the gas in cylinder = T = 21°C = 21 + 273 K = 294 K
PV = nRT ( ideal gas equation )


P = 23.88 atm ≈ 23.9
Partial pressure of the individual gas will be determined by the help of Dalton's law:
partial pressure = Total pressure × mole fraction of gas
Partial pressure of the oxygen gas


Partial pressure of the helium gas


0.1 moles of chloride ions were involved in the reaction if 25.0 mL of a 2.00 M CaCl2 solution is used for the reaction.
Explanation:
Data given:
volume of Ca
= 25 ml 0r 0.025
molarity of the calcium chloride solution = 2M
number of chloride ions =?
Balance chemical reaction:
Ca + 2
⇒
number of moles in 25 ml is calculated as:
molarity = 
number of moles of calcium chloride = molarity x volume
putting the values in the equation:
number of moles = 2 x 0.025
= 0.05 moles of calcium chloride
1 mole of Ca
decomposes as 1 calcium ion and 2 chloride ions
so 0.05 moles will have x moles of chloride ion
= 
x= 0.1
0.1 moles of chloride ions will be involved in the reaction.