Answer: The answer is C. replacement
This would be an example of a replacement type of reaction. As the iron is replaced with the aluminum in the reaction.
Explanation:
The rate of reaction between oxygen and copper is higher at high temperature. The rate of reaction between oxygen and copper is lower at room temperature.
at high temperature copper penny will react with oxygen as shown below

The reaction does not occur easily at room temperature
We can say that the reaction between copper and oxygen is an endothermic reaction so the rate of reaction is high at high temperature.
The bond energy of oxygen molecules need energy to react with copper and form copper oxide.
Answer:
48 g S
Explanation:
Step 1: Define
Molar Mass of Sulfur (S) - 32.07 g/mol
Step 2: Use Dimensional Analysis
= 48.105 g S
Step 3: Simplify
We have 2 sig figs.
48.105 g S ≈ 48 g S
Answer:Methane gas is evolved from the reaction mixture.
Explanation:
When ethyl acetoacetate is treated with grignard reagent a carbanion is generated.
There are two acidic hydrogens which are present on the carbon which is in between the ester and the ketone group in ethylacetoacetate.
These two protons are also called active methylene protons and they are very acidic in nature due to the presence of two electron withdrawing substituents that is an ester and ketone.
CH₃MgBr is grignard reagent and it is an organo-metallic copmpound . Carbon here in CH₃MgBr exists as carbanion CH3⁻ which is basic enough to abstract the acidic protons present on ethylacetoacetate.
As CH3⁻ abstracts an acidic proton from ethylacetoacetate it become CH₄ which is methane. As methane is a gas so it is methane gas which is evolved from the reaction mixture.
As the acidic proton is abstracted from ethylacetoacetate which leads to generation of carbanion and this carbanion is very stable as it can be delocalized on to the two carbonyl groups . As we add aqueous acid to the reaction mixture the carbanion can again be protonated and its protonation would lead to the generation of ethylacetoacetate again.
These are just a couple ways to identify unknown minerals,touch taste smell