Copper II sulfate solution is blue.
Chromatography is used in purification. Drugs analysts may use the technique to separate the active molecule in a drug molecule, for efficacy or toxicity analysis, from the other drug components.
Explanation:
Chromatography is used to separate a mixture of different components based on the size of their molecules. In liquid chromatography, the mixture is dissolved in a solvent that acts as the mobile phase and then passed along a stationary phase with different kinds of pores, As the mixture passes through the pores, their different components are separated because they take different times to pass through the stationary phase because of their different rates in passing through the pores.
In gas chromatography, a gas is used as a mobile phase while a liquid is used as the stationary phase.
Learn More:
For more on chromatography check out;
brainly.com/question/13232854
#LearnWithBrainly
Answer : The reagent present in excess and remains unreacted is, 
Solution : Given,
Moles of
= 3.00 mole
Moles of
= 2.00 mole
Excess reagent : It is defined as the reactants not completely used up in the reaction.
Limiting reagent : It is defined as the reactants completely used up in the reaction.
Now we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,

From the balanced reaction we conclude that
As, 2 moles of
react with 1 mole of 
So, 3.00 moles of
react with
moles of 
From this we conclude that,
is an excess reagent because the given moles are greater than the required moles and
is a limiting reagent and it limits the formation of product.
Hence, the reagent present in excess and remains unreacted is, 
Option B:
Global climate is complex, so changes in global climate are hard to predict.
The balanced chemical equation for the formation ammonia is
N2(g) + 3H2(g) ----> 2NH3(g) .
The balanced chemical equations explains that the same number of each element exist as reactants and products. The coefficients in a balanced equation must be the simplest whole number ratio. Mass is always conserved in chemical reactions.
For the formation of ammonia, the chemical equation is
N2(g) + H2(g) ----> NH3(g)
Balancing the chemical reaction, we can write,
N2(g) + 3H2(g) ----> 2NH3(g) .
This equation shows two nitrogen entering the reaction together and two hydrogens entering the reaction together. Since NH3 is multiplied by a coefficient of 2 there are now 2 nitrogen and 6 hydrogens. The 6 hydrogens come from the 2 multiplied by the subscript of 3. This is the balanced chemical reaction.
To learn more about Balanced chemical equation please visit:
brainly.com/question/14072552
#SPJ4