Answer:
Ordinary table salt is called sodium chloride. It is considered a substance because it has a uniform and definite composition. All samples of sodium chloride are chemically identical. Water is also a pure substance. Salt easily dissolves in water, but salt water cannot be classified as a substance because its composition can vary. You may dissolve a small amount of salt or a large amount into a given amount of water. A mixture is a physical blend of two or more components, each of which retains its own identity and properties in the mixture . Only the form of the salt is changed when it is dissolved into water. It retains its composition and properties.
Homogeneous Mixtures
A homogeneous mixture is a mixture in which the composition is uniform throughout the mixture. The salt water described above is homogeneous because the dissolved salt is evenly distributed throughout the entire salt water sample. Often it is easy to confuse a homogeneous mixture with a pure substance because they are both uniform. The difference is that the composition of the substance is always the same. The amount of salt in the salt water can vary from one sample to another. All solutions would be considered homogeneous because the dissolved material is present in the same amount throughout the solution.
One characteristic of mixtures is that they can be separated into their components. Since each part of the mixture has not reacted with another part of the mixture, the identities of the different materials is unchanged.
Answer:
Half life = 1 / k[Ao]
Explanation:
From:
1/ [A] = kt + 1/ [Ao]
Isolating t on its own, we have:
kt = 1 / [A] - 1 / [Ao]
t = 1 / [Ao] / k
Re-arranging we have:
t = 1 / k [Ao]
The t represents the t=half life of the second order reaction and the formula can be re-written as:
t1/2 = 1 / k [Ao]
This is so because second order reaction decreases at a much faster rate than zero and first order reactions and there slopes decreases to zero at a much faster rate.
Answer: use the ideal gas equation, PV = nRT
Explanation:
The ideal gas equation permits you to determine one variable, P, V, n or T, when you know the other two variables.
In this case, your are told you know P, V and T, so you can solve for n:
n = PV / (RT)
Remember this:
R is the universal constant of gases, and you must use the adequate units.
T is the temperature in absolute scales, i.e Kelvin.
An exothermic reaction is a chemical reaction that releases energy by light or heat. It is the opposite of an endothermic reaction. im sorry i only could do one! but hope this helped!