The number of particles (molecules or atoms) is: 6.022 x 10²³ particles (atoms or molecules).
1 mol of H₂O has 6.022 x 10²³ molecules.
1 mol of Al has 6.022 x 10²³ atoms.
The reaction CO₂(g) → C(s) +O₂(g) is a decomposition reaction is true
Explanation
A Decomposition reaction is a reaction in which involve breaking down a compound into two or more simpler substances.
The reaction above is a decomposition reaction since CO₂ molecule is broken down into C (an element) and O₂ (a molecule).
<h3>Answer:</h3>
The Alkane formed is 5,5-dibromo-2,2,3-trimethylhexane. as shown below in attached scheme (Green Color).
<h3>Explanation:</h3>
Alkynes like Alkenes undergo <em>Electrophillic Addition Reactions</em>. The reaction given is a two step reaction. In step 1, the Alkyne adds first equivalent of HBr obeying <em>Markovnikov's rule</em> (i.e. Bromine will add to carbon containing less number of hydrogen atoms) and forms <em>2-bromo-4,5,5-trimethylhex-1-ene</em>. In step 2, the alkene formed in first step (2-bromo-4,5,5-trimethylhex-1-ene) undergoes addition reaction with the second equivalent of HBr via Markovnikov's rule to produce <em>5,5-dibromo-2,2,3-trimethylhexane</em>.
The scheme is attached below, Blue color is assigned to starting Alkyne, Red color is assigned to intermediate Alkene and Green color is assigned to product Alkane respectively.