The correct option is this: EFFUSION BECAUSE THERE IS A MOVEMENT OF A GAS THROUGH A SMALL OPENING INTO A LARGER VOLUME.
Effusion refers to the movement of gas particles through a small hole. According to Graham's law, the effusion rate of a gas is inversely proportional to the square root of the mass of its particles.
Answer:
3) The calculated density would be high, because the volume would be incorrectly measured low.
Explanation:
Density is defined as mass per unit volume. It means the density is inversely proportional to the volume.
A solid with a hollow center will have high volume due to air inside the hollow area that will lead to low density.
But the error in the calculation of density is that the "density would be high, because the volume would be incorrectly measured low."
Hence, the correct answer is "3)"
Answer: 
molecules of water are produced.
Explanation:
To calculate the moles :
The balanced chemical reaction is:
According to stoichiometry :
2 moles of 
produce = 3 moles of 
Thus 0.707 moles of will produce=
of
According to avogadro's law, 1 mole of every substance contains avogadro's number 
of particles.
Thus 1.06 moles of contains = 
molecules
