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Well...it says ALL the Oxygen in the dry air is reacted...the percentage of Oxygen i air is 20%
it is a reversible reaction...when you add water to blue solid (anhydrous cobalt chloride) it will become hydrated that is, will change to pink....this is an exothermic reaction so the temperature rises and therefore the answer is B
it is a reversible reaction...when you add water to blue solid (anhydrous cobalt chloride) it will become hydrated that is, will change to pink....this is an exothermic reaction so the temperature rises and therefore the answer is B
yes, jazakallah
wa eyyakumyes, jazakallah
but i didnt get how is this reaction exothermic?it is a reversible reaction...when you add water to blue solid (anhydrous cobalt chloride) it will become hydrated that is, will change to pink....this is an exothermic reaction so the temperature rises and therefore the answer is B
it is exothermic bcoz the temperature increases
i know thisit is exothermic bcoz the temperature increases
LOLi know this
i want to that how is adding water an exothermic reaction?
& how would i know just by reading the question that the temperature increased or that the reaction is exothermic?
ok i will explain it in a very simple way, this reaction is a basic reversible reaction if u start first with hydrated copper sulfate and u heat it this is the forward reaction and it is obviously endothermic, the backward reaction is when the anyhdrous copper sulfate is turned back to hydrated and this can only be done by adding water and as this is backward then it must be the opposite of the forward reaction and so it is exothermic.i know this
i want to that how is adding water an exothermic reaction?
& how would i know just by reading the question that the temperature increased or that the reaction is exothermic?
oh jazakallah got it
jazakallah once againLOL
bcoz heat is liberated
okie! on a serious note...there are some reactions which you should know/memorize whether are they endothermic or exothermic...for instance neutralization reactions, combustion reactions e.t.c!
so juss remember that this reaction...that is adding water to anhydrous salts is ALWAYS exothermic!
hope that helps
yea when they ask for the temperature change, they are asking for the temperature of the surroundingsoh jazakallah got it
& just one more thing:
when deciding whether temp increases or decreases we have to consider the temp of the surrounding ???
jazakallah a lotyea when they ask for the temperature change, they are asking for the temperature of the surroundings
View attachment 12402
I tried my best to clear your doubts...if still you need any help you are free to ask
aoa wr wb...Another doubt, please help
An excess of dilute hydrochloric acid is added to aqueous sodium hydroxide. What is the pH of the aqueous sodium hydroxide before the acid is added, and what is the pH of the final mixture?
KEY
pH of aqueous sodium hydroxide
pH of final mixture
Option A: 3 7
Option B:7 3
Option C:12 3
Option D:12 7
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