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Biology; Chemistry; Physics: Post your doubts here!

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you have to balance the charges on both sides too, so you put a 2 before the Cu on the right side, so that the total charge is 4+ like on the left hand side
That doesn't make any sense, from what I've studied, there is no charge on an ATOM. Only ions have charge
 
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That doesn't make any sense, from what I've studied, there is no charge on an ATOM. Only ions have charge
When you put the 4 before the hydrogen ion on the left, the charge on the left side became +4. Now to balance that charge, you put a 2 before the Cu2+ ion on the right hand side. And then to balance Cu atom, you put a 2 before it on the left hand side........ ok?
 
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what about june 06 p2 Q A1 (c)....the answer is Al2O3,,how?
Non metals form either neutral or acidic oxides, so there can be no non metal as the answer. All metals apart from amphoteric form basic oxides so they can't be the answer. Only amphoteric form both oxides and aluminum is amphoteric
 
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When you put the 4 before the hydrogen ion on the left, the charge on the left side became +4. Now to balance that charge, you put a 2 before the Cu2+ ion on the right hand side. And then to balance Cu atom, you put a 2 before it on the left hand side........ ok?
what...if i put 4H+ for 2H2 then i sould put 2Cu for Cu2+....but ms says 2Cu and 2Cu2+
 
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When you put the 4 before the hydrogen ion on the left, the charge on the left side became +4. Now to balance that charge, you put a 2 before the Cu2+ ion on the right hand side. And then to balance Cu atom, you put a 2 before it on the left hand side........ ok?
But then why is there a 2Cu2+ in the mark scheme? :(
 
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what...if i put 4H+ for 2H2 then i sould put 2Cu for Cu2+....but ms says 2Cu and 2Cu2+
2Cu + O2 + 4H+ = 2Cu2+ + 2H2O

first of all this equation is right. The thing is you have to balance the charges as well as the atoms on both sides. Now when we put the 2 before water, we had to put 4 before the H ion on the left side to balance the atoms H. Now, there is a total charge of 4+ on the left hand side. To balance this, we put a 2 before the Cu2+ ion, so that the total charge becomes 4+ here too. Now, as we increased the Cu ions on the right side to two, we have to put a 2 before the Cu atom on the left side
 
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my question is
Non metals form either neutral or acidic oxides, so there can be no non metal as the answer. All metals apart from amphoteric form basic oxides so they can't be the answer. Only amphoteric form both oxides and aluminum is amphoteric
my question is, why Al2O3 (unreactive) reacts with O2..syllabus doesnt include learning about the out comes when a metal oxide reacts again with O2
 
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2Cu + O2 + 4H+ = 2Cu2+ + 2H2O

first of all this equation is right. The thing is you have to balance the charges as well as the atoms on both sides. Now when we put the 2 before water, we had to put 4 before the H ion on the left side to balance the atoms H. Now, there is a total charge of 4+ on the left hand side. To balance this, we put a 2 before the Cu2+ ion, so that the total charge becomes 4+ here too. Now, as we increased the Cu ions on the right side to two, we have to put a 2 before the Cu atom on the left side

Thank you so much!!
 
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my question is
my question is, why Al2O3 (unreactive) reacts with O2..syllabus doesnt include learning about the out comes when a metal oxide reacts again with O2
i think the answer should have been simply Al. there is something wrong with the mark scheme. Cuz the question specifically asks which ELEMENT, not COMPOUND. So, aluminium reacts with air to form an amphoteric oxide. Understand?
 
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my question is
my question is, why Al2O3 (unreactive) reacts with O2..syllabus doesnt include learning about the out comes when a metal oxide reacts again with O2
It doesn't :p
The mark scheme Has written the answer with respect to the question, the answer is Aluminum not aluminum oxide :p
 
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i think the answer should have been simply Al. there is something wrong with the mark scheme. Cuz the question specifically asks which ELEMENT, not COMPOUND. So, aluminium reacts with air to form an amphoteric oxide. Understand?
let me write the qs:
an element that reacts with oxygen to give acidic oxide .... and the answer is aluminium oxide..
what u have to say about this?
 
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