First, find moles of gold given the mass of the sample:
(35.9g Au)/(197.0g/mol Au) = 0.182mol Au
Second, multiply moles of Au by Avogrado's number:
(0.182mol)(6.02 x10^23)= 1.10x10^23 atoms Au
Copper choruses purpose is its used as a catalyst for organic and inorganic reactions , mordant for dyeing and printing textiles, pigment for glass and ceramics, wood preservative, disinfectant, insecticide, fungicide, and herbicide. (Not sure if you want the actual purpose of water or not)
Answer:
69.8 kilo Pasacl is the pressure of the hydrogen gas.
Explanation:

Pressure at which hydrogen gas collected = p = 101.2 kilo Pascals
Vapor pressure water =
= 31.4 kilo Pascals
The pressure of hydrogen gas = P
The pressure at which gas was collected was sum of vapor pressure of water and hydrogen gas.


69.8 kilo Pasacl is the pressure of the hydrogen gas.
Answer:
There are 2500000 milligrams in 2.5 kg