Answer: Mass of 
produced in this reaction was 6.56 grams
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Mass or reactants = Mass of 
+ mass of 
= 16.00 + 64.80 = 80.80 g
Mass of products = mass of aqueous solution + mass of + = 74.24 + x g
Mass or reactants = Mass of products
80.80 g = 74.24 + x g
x = 6.56 g
Thus mass of produced in this reaction was 6.56 grams
Explanation:
A mixture in which there is uniform distribution of solute particles into the solvent is known as a homogeneous mixture.
For example, sugar dissolved in water is a homogeneous mixture.
On the other hand, a mixture in which there is uneven distribution of solute particles into the solvent is known as a heterogeneous mixture.
For example, sand present in water is a heterogeneous mixture.
Comment on given situations will be as follows.
(a) Air in a closed bottle - It is a homogeneous mixture because there will be even distribution of other gases that are present in air.
(b) Air over New York City - It is a heterogeneous mixture because there will be presence of some dust particles, fog or smoke into the air. Distribution of all these particles will be uneven. This will make air over New York City heterogeneous in nature.
Squeezing just the juices out of the orange, like with your hand or whatever you use, is a physical change. yes :)
There are 18 protons and electrons and 22 neutrons in the atom
