Answer:
5*10²⁴ chlorine atoms are found in 8.3 moles of chlorine.
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number represents a quantity without an associated physical dimension, so it is considered a pure number that allows describing a physical characteristic without an explicit dimension or unit of expression. Avogadro's number applies to any substance.
Then you can apply the following rule of three: if 1 mole of the compound contains 6.023 * 10²³ atoms, 8.3 moles of the compound how many atoms does it have?

amount of atoms≅ 5*10²⁴ atoms
<u><em>5*10²⁴ chlorine atoms are found in 8.3 moles of chlorine.</em></u>
Presuming the arrow is between H20 and CO
On the left there are 2 gas moles.
On the right there are 4 gas moles.
The equilibrium will shift to the side with the most no. He gas moles when pressure is decreased.
Therefore the answer is A, since 4>2.
If you have any questions, feel free to ask
Answer : (C) Hafnium is the most likely identity of the given substance.
Solution : Given,
Mass of given substance (m) = 46.9 g
Volume of given substance (V) = 3.5 
First, find the Density of given substance.
Formula used :

Now,put all the values in this formula, we get
= 13.4 g/
So, we conclude that the density of given substance (13.4 g/
) is approximately equal to the density of Mercury and Hafnium (13.53 and 13.31 g/
respectively).
According to the question the substance is solid at room temperature but Mercury is liquid at room temperature. So, Mercury is not identical to the given substance.
Another element i.e, Hafnium is the element whose density is approximately equal to the given substance and also solid at room temperature. And we know that the melting point of solid is high.
So, Hafnium is the most likely element which is the identity of the given substance.
Answer:

Explanation:
Incorrect use has resulted in accidents and disfiguring burns. Never leave a methylated spirit appliance unattended. Also make sure that the camping stove or appliance is on a flat surface and that the fuel cannot spill out.
POH will be -log[conc of OH]
-log (3.9E-08) = 7.409
pH = 14- pOH
pH = 14 - 7.409
pH = 6.59