To solve this problem, we must be given first the density
of air at 20 degrees Celsius. Looking up online, this is equal to:
density air (20C) = 0.0012041 g/mL
so that the volume is:
volume balloon = 0.57 g / (0.0012041
g/mL)
<span>volume balloon = 473.38 mL</span>
Answer : The freezing point of a solution is 
Explanation : Given,
Molal-freezing-point-depression constant
= 
Mass of urea (solute) = 29.82 g
Mass of solvent = 500 g = 0.500 kg
Molar mass of urea = 60.06 g/mole
Formula used :

where,
= change in freezing point
= freezing point of solution = ?
= freezing point of solvent = 
i = Van't Hoff factor = 1 (for urea non-electrolyte)
= freezing point constant = 
m = molality
Now put all the given values in this formula, we get


Therefore, the freezing point of a solution is 
For neutralization of acid by a base (or vice versa), the equation should be used.
M₁V₁ = M₂V₂
where M's are the molarity and the Vs are the volume. Substituting the known values,
(0.150M)(25) = M₂(15 mL)
The value of M₂ from the equation is equal to 0.25M. Thus, the concentration of the acid is 0.25M.
Answer:
K2 +Br ->2KBr
K + I ->KI
actually I don't know the e option but I had tried can u pls balance it urself
Answer:
P₂ = 2 atm
Explanation:
Given data:
Initial volume = 10.0 L
Initial pressure = 4.0 atm
Final volume = 20.0 L
Final pressure = ?
Solution:
The given problem will be solved through the Boly's law,
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
4.0 atm × 10.0 L = P₂ × 20.0 L
P₂ = 40.0 atm. L/ 20.0 L
P₂ = 2 atm