<span>A fast moving stream of air has a lower air pressure than a
slower air stream. As the stream of air moved over the
top of the paper, the air pressure over the paper dropped. The
air pressure underneath the paper stayed the same. The
greater air pressure underneath lifted the paper strip and it
rose. The idea that a moving air stream has lower air pressure
than air that is not moving is called “Bernoulli’s Principle”.
</span>The
force of the moving air underneath the balloon was enough to
hold it up. The weight added by the paper clip prevents
the balloon from going too high. But that is only part
of the story. The balloon stays inside the moving stream
of air because the pressure inside is the air stream is lower
than the still air around it. As the balloon moves toward the
still air outside of the air stream, the higher pressure of
the still air forces the balloon back into the lower pressure
of the air stream. Bernoulli’s Principle at work again!
Solution :
Molar mass of 
is :
M = 6×12 + 6×1 g
M = 78 g
78 gram of contains 
molecules.
So, 89.5 gram of contains :
Now, from the formula we can see that one molecule of contains 2 hydrogen atom . So, number of hydrogen atom are :
Hence, this is the required solution.
Answer:
Explanation:
The expression for the work done is:
Where,
W is the amount of work done by the gas
R is Gas constant having value = 8.314 J / K mol
T is the temperature
P₁ is the initial pressure
P₂ is the final pressure
Given that:
T = 300 K
P₁ = 10 bar
P₂ = 1 bar
Applying in the equation as:
Answer:
the compound contains C, H, and some other element of unknownidentity, so we can’t calculate the empirical formula
Explanation:
Mass of CO2 obtained = 3.14 g
Hence number of moles of CO2 = 3.14g/44.0 g = 0.0714 mol
The mass of the carbon in the sample = 0.0714 mol × 12.0g/mol = 0.857 g
Mass of H2O obtained = 1.29 g
Hence number of moles of H2O = 1.29g/18.0 g = 0.0717 mol
The mass of the carbon in the sample = 0.0717 mol × 1g/mol = 0.0717 g
% by mass of carbon = 0.857/1 ×100 = 85.7 %
% by mass of hydrogen = 0.0717/1 × 100 = 7.17%
Mass of carbon and hydrogen = 85.7 + 7.17 = 92.87 %
Hence, there must be an unidentified element that accounts for (100 - 92.87) = 7.13% of the compound.
