What happens when?
2) a few drops of methyl orange reacts with sodium carbonate solution
3)carbon dioxide is passed into lime water
Answer:
You dealing with are acid-base reactions here.
1) Caustic soda is sodium hydroxide (NaOH). The reaction is:
NaOH + HCl --> NaCl + H2O
3) Lime water is a solution of calcium hydroxide (Ca(OH)2). The reaction is:
Ca(OH)2 + CO2 --> CaCO3 + H2O
Calcium carbonate is only slightly soluble in water, so it will come out of solution, and your lime water will look cloudy.
2) This needs a little extra research. Look up methyl orange on Wikipedia:
http://en.wikipedia.org/wiki/methyl_oran...
So you must understand that when the pH is less than 3.1, this indicator will color the solution red, if pH is over 4.4 it will color the solution yellow, and for pH between 3.1 and 4.4, you will get different shades of orange. This is because methyl orange (just by itself in water) reacts with water:
M + H2O <--> [M-H+] + [OH-]
with the "M" standing for the methyl orange molecule. The double-headed arrow means the reaction is in equilibrium, and can go both ways, but at the same rate. The H from the water attaches itself to the left-most N in that drawing on Wikipedia, and the whole chemical species is positively charged (cationic). This changes the arrangement of electrons on the molecules, and the net effect is a change in color. But if the pH is high enough, less [M-H+] is formed (the larger amount of OH- will rip off the H and become water).
Back to the question: sodium carbonate will make a solution basic (pH > 7), so the methyl orange will color the solution yellow rather than orange or red.
A CHEMICAL REACTION
AS NONE BEFORE.
BEST
a chemical reaction
1) NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
The answers post by the user, for information only, FunQA.com does not guarantee the right.
More Questions and Answers: