<u>Answer:</u> The molarity of citric acid that is commercially available lemon juice is 0.416 M
<u>Explanation:</u>
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

Hence, the molarity of citric acid that is commercially available lemon juice is 0.416 M
Answer: 10ml
In this question, you are given the liquid medicine concentration (100mg/5ml) and the doses of the medicine that must be taken(200mg). You are asked how much ml of the drug needed. Then the calculation would be:
Volume of drug needed= doses of the drug / drug concentration
Volume of drug needed= 200mg / (100mg/5ml)= 10ml
Answer :
An egg cooking is an endothermic reaction.
A candle burning and Plaster & water combining and becoming warm are exothermic reaction.
Salt being added to water, with no change in temperature neither endothermic nor exothermic reaction.
Explanation :
- Endothermic reaction : It is a type of reaction in which energy is absorbed in the form of heat from the surroundings.
- Exothermic reaction : It is a type of reaction in which energy is released in the form of heat from the system.
An egg cooking : In this process, the energy is absorbed in the form of heat.
A candle burning and Plaster & water combining and becoming warm : In both the process, the energy is released in the form of heat.
Salt being added to water, with no change in temperature : In this process, neither energy released nor absorbed.
<span>There are three different subatomic particles present in the atoms of each element: neutron, proton and </span>electron<span>. It is the </span>electrons<span>, and more specifically the valence </span>electrons<span>, that determine the reactivity of an element.</span>