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Please help me make a redox reaction

Posted: Wed Jan 15, 2025 10:54 am
by Zalerant
Hello.
I would be grateful if you could help me formulate such a redox reaction:
Ca+K2Cr2O7+H2SO4-->Cr2(SO4)3+....+..... 📖
They say that you need to use the electronic balance method, but I don't understand how to do it. Help me make up a reaction, please

Re: Please help me make a redox reaction

Posted: Wed Jan 15, 2025 12:39 pm
by ChenBeier
Bad example
Cr2O7 2- => Cr 3+ Redoxpair
Cr2O7 2- + 14 H+ => 2 Cr 3+ + 7 H2O Remove oxygen by water

Cr2O7 2- + 14 H+ + 6 e- => 2 Cr 3+ + 7 H2O Balance Charge

Ca => Ca 2+ Redoxpair
Ca=> Ca 2+ + 2e- Balance Charge
3 Ca => 3 Ca 2+ + 6 e-Balance electrons

Cr2O7 2- + 14 H+ + 3 Ca => 2Cr 3+ + 3 Ca 2+ 7 H2O Addition of both equation
K2Cr2O7 +7 H2SO4 + 3 Ca => Cr2(SO4)3 + 3 CaSO4 + K2SO4 + 7 H2O Add spectator ions
Finished

Re: Please help me make a redox reaction

Posted: Fri Jan 17, 2025 8:51 pm
by StevenAppell
THANKS

Re: Please help me make a redox reaction

Posted: Sun Feb 16, 2025 11:30 pm
by sofiacals
ChenBeier wrote: Wed Jan 15, 2025 12:39 pm Bad example
Cr2O7 2- => Cr 3+ Redoxpair
Cr2O7 2- + 14 H+ => 2 Cr 3+ + 7 H2O Remove oxygen by water

Cr2O7 2- + 14 H+ + 6 e- => 2 Cr 3+ + 7 H2O Balance Charge

Ca => Ca 2+ Redoxpair
Ca=> Ca 2+ + 2e- Balance Charge
3 Ca => 3 Ca 2+ + 6 e-Balance electrons

Cr2O7 2- + 14 H+ + 3 Ca => 2Cr 3+ + 3 Ca 2+ 7 H2O Addition of both equation
K2Cr2O7 +7 H2SO4 + 3 Ca => Cr2(SO4)3 + 3 CaSO4 + K2SO4 + 7 H2O Add spectator ions
Finished
A perfect answer.
Thanks