When mixing Hydrochloric acid and Sodium hydroxide to neutralize with few drops of phenolphthalein indicator solution. I added too much sodium hydroxide, the mixture turns dark pink Is there a new color appearing ?? Is it a chemical change?
If residue is left after heating the mixture. (hint: reaction of an acid with a base produces salt and water) What is the residue?
I have no idea PLZ HELP!! BIG THX!
2006-12-10 06:30:16 · 3 answers · asked by Unanswered 1 in Science & Mathematics ➔ Chemistry
the pink color means the phenolphthalein has changed its chemistry
acid/base reactions are chemical reactions producing new substances (water and salts)
hydrochloric acid is HCl -
sodium hydroxide is NaOH
The H from the acid and the OH from the base form water.
That leaves Na from the base to combine with the Cl from the acid - you can figure out the salt from that
HCl + NaOH = HOH + NaCl
2006-12-10 06:34:43 · answer #1 · answered by The Old Professor 5 · 0⤊ 0⤋
CHEMICAL. Physical is what you do to a piece of paper when you rip it apart. You my have changed its appearance, but you have not changed the fact that it is paper, its identity. Its chemical composition has not changed. usually it's something like bending, breaking, cracking, splitting, etc. Chemical is when you change the molecular structure or something. Baking is a chemical reaction, believe it or not. Where do you think the air pockets in bread come from? Gas released because of a chemical reaction. plus the cake is turning from liquid to solid.
2016-05-23 02:29:57 · answer #2 · answered by Anonymous · 0⤊ 0⤋
it's chemical!!
2006-12-10 06:38:51 · answer #3 · answered by skittle 2 · 0⤊ 0⤋