Answer: Option (c) is the correct answer.
Explanation:
When a system is open then there will be exchange of energy between the system and surrounding.
Whereas when a system is closed then there will be no exchange of energy, that is, thermal energy will not flow into the atmosphere.
Thus, we can conclude that a sealed calorimeter is a closed system because thermal energy is not transferred to the environment.
Answer:
C. physical
Explanation:
A mixture is a physical combination. Mixtures are combinations of compounds and molecules without any chemical reaction taking place.
Mixtures have the following properties:
- They have an indefinite composition i.e they consist of two or more elements and or compounds in any proportion by mass
- Their constituents retains their identities i. e physical property is retained.
- Their constituents reacts differently to changed conditions.
- They are easily separated into constituents by physical methods
Explanation:
subscript is K
superscript is ^
subscript K means a unit of temperature like F or C
superscript ^ means to the power of
So all together it means to the power of 40 K
Answer: The statement (B) is not true about chemical reactions.
Explanation:
A chemical reaction rate is affected by the several factors few of which are temperature, concentration of reactants, surface area etc.
In a chemical reaction, if temperature is increased then the rate of reaction will increase because it will increase the average kinetic energy of the reactant molecules. Thus, large number of molecules will have minimum energy required for an effective collision.
It is known that increasing the amount of reactants will increase the rate of reaction.
Therefore, rate of reaction will change if concentration or temperature is changed.
Hence, the statement (B) is not true about chemical reactions.
nonpolar covalent bond (with LD force)
