Answer:
a. Heat is often absorbed during reactions.
c. Heat is often released during chemical reactions.
Explanation:
Thermochemistry -
The study of thermochemistry involve the change in the amount of heat , during any physical or chemical process , is referred to as thermodynamics .
The focus of thermochemistry is on the changing amount of energy in the form of heat , on the system with respect to the surroundings .
The process like boiling , melting , sublimation , may require energy or releases energy , and hence are studied under thermochemistry .
Hence , from the given question ,
The correct options are - a , c.
There is different types of salt.
1)table salt
2)lime salt
Answer:
a. Hydrocarbons have low boiling points compared to compounds of similar molar mass.
b. Hydrocarbons are hydrophobic.
d. Hydrocarbons are insoluble in water.
Explanation:
As we know that the hydrocarbons is a mix of carbon and hydrogen. In this the availability of the electronegative atom is not there that shows there is no bonding of the hydrogen plus it is dissolved. Also, the hydrocarbons is considered to be a non-polar but as compared to the water, water is a polar
In addition to this, the strong bond is no existed that shows the lower boiling points
Therefore option A, B and D are right
Answer:
B. Na+ and O2-
Explanation:
Na+ plus has 10 electrons and O2- also has 10 electrons