Answer:
A smallest particle of an element that can take part in a chemical reaction is called an atom.
Explanation:
Half-life time of a reaction is time at which reactant concentration becomes half of its initial value.
Half-life of the first order reaction is 20 min. Rate constant can be calculated as follows:
The rate expression for first order reaction is as follows:
initial number of molecules of reactant are , time is 100 min thus, putting the values to calculate number of reactant at time 100 min,
On rearranging,
Or,
Therefore, number of molecules unreacted will be
Formula M1V1 =M2V2
1.5 * 100 = M2 *300
M2 = 1.5*100/300= 0.5.
Answer: the molarity is 0.5M.
Answer:
Explanation:
Earth is considered a closed system because only energy, not matter, is exchanged. A closed system like Earth can be easily represented by a sealed jar. When the lid is sealed, matter like air or water can neither enter nor exit the jar. If you placed that same jar in a 100-degree oven, the air inside the jar would eventually increase in temperature to 100 degrees, representing an exchange of energy known as heat.