Answer:
Reactants starts the chemical reaction and gives right to the product either by thermal decomposition or in the presence of a catalyst.
Explanation:
Reactants and products contain the same atoms, but they are rearranged during the reaction, so reactants and products are different substances.
Answer:
2HCI + Na2S ----> H2S + 2NaCl
Explanation:
For a balanced chemical equation, the number of moles of atoms on the reaction side must equal the number of moles of atoms on the product side, in accordance with the law of conservation of mass.
The correct answer is:
2HCI + Na2S ----> H2S + 2NaCl
Since it has equal number of moles of each atom on both sides of the equation: 2 atoms each of hydrogen, chlorine, and sodium on both sides of the equation as well as 1 atom of sulphur on both sides of the equation.
Answer:
while analogous structures show that similar selective pressures can produce similar adaptations (beneficial features). Similarities and differences among biological molecules can be used to determine species' relatedness.
Explanation:
Answer:
The value of n in the hydrate formula is 5 ,
.
Explanation:

Mass of hydrate of copper sulfate = 14.220 g
Moles of hydrate of copper sulfate =
Mass of copper sulfate after heating = 8.9935 g
Moles of copper sulfate = 

Solving for n, we get:
n = 5
The value of n in the hydrate formula is 5 ,
.