Answer:
A is an endothermic reaction.
Explanation:
When energy of breaking bonds is greater than the energy released during making of bonds, we need to supply energy to the reaction and thus the reaction is called as endothermic reaction. We can also say that the enthalpy of formation of products is more than the enthalpy of formation of reactants making overall enthalpy change to be positive.
While in case B, the energy to break bond is less than the energy released during making of bonds. thus there is overall released of energy during the reaction and hence it is exothermic reaction.
The balanced equation is 2H2 + O2 –> 2 H2O. It takes two hydrogen atoms for every oxygen atom to produce this reaction, so the mole ratio between hydrogen and oxygen is 2:1
Answer is 2:1
<u>Answer:</u> The correct answer is heat will flow from the boiling water into the frozen metal.
<u>Explanation:</u>
According to the law of conservation of energy, energy cannot be destroyed nor created but it can be transformed from 1 form to another form.
There are 3 processes of heat transfer:
- <u>Conduction:</u> This type of heat transfer occurs when there is direct contact between the two objects.
- <u>Convection:</u> This type of heat transfer occurs when there is a movement of fluid (liquid or gas) due to the movement of hot layers to the top and cold layers to the bottom which leads to convection currents.
- <u>Radiation:</u> This type of heat transfer occurs when there is a direct transfer of energy through space.
The heat moves from a hot surface to a cold surface to maintain equilibrium.
We are given:
A metal is placed in a freezer (cold object) and another metal is placed in an oven (hot object) and then both the metals are placed in boiling water.
Initially, the heat will flow from the boiling water (hot object) into the frozen metal (cold object) to maintain equilibrium
Hence, the correct answer is heat will flow from the boiling water into the frozen metal.
Answer:
The correct order it b. always add acid last.
Explanation:
Adding acid first could result on a violent reaction and heat or fumes can be generated. The best approach is to always add all the water or non-acid component first, or add a significant portion before adding the acid slowly to the mixture.
