Answer: It is an exothermic process because heat energy is absorbed by the water as the NaOH(s) dissolves in it.
Explanation:
Endothermic reaction : It is a type of chemical reaction where the energy is absorbed from the surrounding. In the endothermic reaction, the reactant are less than the energy of product. In endothermic reaction, the change in enthalpy is, positive
Exothermic reaction : It is a type of chemical reaction where the energy is released into the surrounding. In the exothermic reaction, the energy of reactant are more than the energy of product. In exothermic reaction, the change in enthalpy is, negative.
Thus as energy is absorbed by water, which has been released by NaOH, the process is exothermic.
Answer:
a. 7.52
b. 16.5
c. 85
d. 6.03
Explanation:
significant number exempts 0 as a number which explains the last one. The two significant numbers there are 6 and 3
The toxic gar expelled from the reaction between gasoline and oxygen in the vehicle's engine is both Carbon dioxide and monoxide
Answer:
This element is Rubidium (Rb) and has an average atomic mass of 85.468 u
Explanation:
The average mass of an element is calculated by taking the average of the atomic masses of its stable isotopes.
The enitre atomic mass = 100 % or 1
⇒ this consists of X-85 with 72.17 % abundance with atomic massof 84.9118 g/mol
72.17 % = 0.7217
⇒ this consists of X-87 with 27.83 % abundance with atomic mass of 86.9092 g/mol
27.83 % = 0.2783
To calculate the mass of this isotope we use the following:
0.7271 * 84.9118 + 0.2783 * 86.9092 =85.468 g/mol
This element is Rubidium(Rb) and has an average atomic mass of 85.468 u
