Empirical formula is the simplest ratio of whole numbers of components in a compound
in 100 g of compound
C H O
mass 25.5 g 6.40 g 68.1 g
number of moles 25.5 g/12 g/mol 6.40 g/ 1 g/mol 68.1 g/ 16 g/mol
= 2.13 mol = 6.40 mol = 4.26 mol
divide by least number of moles
2.13/2.13 = 1 6.40/2.13 = 3.0 4.26/2.13 = 2.0
all rounded off
C - 1
H - 3
O - 2
empirical formula - CH₃O₂
Chemical bonds are formed or broken. This is true of a chemical change, but not a physical change. A physical change is usually something that you can see, such as changing of shape or form or staying the same. However, because you cannot visibly see chemical bonds being formed or broken and because this would affect the chemical composition, it is not a physical change.
City
<u>Explanation:</u>
The best analogy to explain the functions performed by a cell is by comparing it to a city.
Just like the city performs a multitude of task by housing critical elements like powerhouse, restaurants, transportation else, same way cell to performs similar functions for the body.
E.g.
- In cell “Mitochondria” provides it with energy or the power in the same way “powerhouse” provides power to the city
- Golgi bodies work as a car for transporting proteins to other parts of the cell.
<span>A) 2NaOH -> 2Na + O2 + H2
is not correct since Na is unstable
B) 2NaOH -> 2Na + H2O + 1/2O2
is not correct since Na is unstable
C) 2NaOH -> Na2O + H2O
is correct since N2O is stable
D) 2NaOH -> 2Na + H2O2
is not correct since Na is unstable</span>
