Answer:
43.96secs
Explanation:
M1 = molar mass of NH3 = 14 + (3x1) = 14 + 3 = 17g/mol
t1 = time for NH3 to diffuse = 30secs
M2 = molar mass of HCl = 1 + 35.5 = 36.5g/mol
t2 = time for HCl to diffuse =?
From Graham's law of diffusion:
t2/t1 = √(M2/M1)
t2/30 = √(36.5/17)
t2/30 = 1.465
Cross multiply
t2 = 30 x 1.465
t2 = 43.96secs
Therefore it will take 43.96secs for the damp blue litmus paper to change colour for HCl.
You could ask whether the black crust is a new substance formed from silver underwent a chemical change because a chemical change produces a new substance.
Answer:
D
Explanation:
single replacement....iron combined with tetraoxosulphate (VI)
1) The mass of 1 mole of virus is
2) There are 5.6 moles of viruses in an oil tanker
Explanation:
1)
One mole of a substance is the amount of that substance containing a number of particles equal to the Avogadro number:
This means that 1 mole of this virus should contain a number of virus particles equal to .
We know that the mass of 1 virus particle is
Therefore, the mass of 1 moles of viruses is equal to the mass of a single virus particle multiplied by the number of virus particles in one mole, :
2)
In this problem, we have that the mass of the oil tanker is
We also know that the mass of one mole of virus is
Therefore, we can find how many moles of viruses have a mass equal to the mass of the oil tanker by dividing the mass of the oil tanker by the mass of 1 mole of virus particles.
Mathematically, this is done by the following operation:
Learn more about number of moles:
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Explanation: