<span>Anthracite is also referred to as hard coal because it is so hard and pure. It is very hard and highly compacted with variety of coal that has submetallic luster. It has highest carbon content, the lowest impurities, and highest density of energy of all the coal deposits.</span>
The correct answer is shown in option 3. Water and hydrochloric acid are polar molecules. These molecules are polar because of the presence of bonds that are partially ionic or polar covalent bonds. Other examples are hydrogen fluoride and ammonia.
Answer: 3.72 M
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = age of sample = 15.0 minutes
a = let initial amount of the reactant = 10.0 M
a - x = amount left after decay process = ?
The concentration of 
in a solution after 15.0 minutes have passed is 3.72 M
Only when there is no product that is when a chemical reaction has not occured
