Answer:
D. A reaction or change in a substance that results in a different substance
Explanation:
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances.
Answer:
1) in excess
Explanation:
Copper oxide is insoluble in water, while acid is soluble in water
Answer : The correct answer is option C.
Explanation:
Astronomers have observed that light from the distant object in the universe is shifted towards the frequency of red color which indicates that those object are receding or moving away from the planet earth.This phenomena was termed as Red shift .Same thing goes for galaxies which are very far away from the planet earth.
Where as if galaxies were moving towards the the planet earth their light would have shifted toward the frequency of blue color termed as blue shift.
Hence, the correct answer is option C.
Correct answer is <span>X = ΔH
Reason:
1) The graph of enthalpy Vs reaction coordinate suggest the reaction is endothermic in nature. For endothermic reaction, energy if product is more than that of reactant. Hence, option 1 i.e. </span><span>X = -ΔH cannot be correct.
2) Since the reaction is endothermic in nature, </span>energy if product is more than that of reactant. Hence, option 2 i.e. X = ΔH is correct.
3) Activation energy is energy difference between Reactant (A) and transition state (B). However, as per option C, activation energy (A.E.) is energy difference between product (C) and transition state (B), which is incorrect.
