Open Question: The difference between energies of formation and energies of atom combination is?
Open Question: How do I calculate the enthalpy change of formation of MgCO3?

Open Question: How do I calculate the enthalpy change of formation of MgCO3?

"When 0.10g of magnesium ribbon was dissolved in an excess of dilute HCl, the temperature rose by 4.3 degrees C.A separate experiment showed that the same volume of acid required 500J to raise the temperature by 1.0 degree C."

From this I was able to work out the enthalpy change per mole of magnesium. The second part of the question is the bit I'm stuck on...

"In a similar experiment, solid magnesium carbonate reacted with an excess of dilute hydrochloric acid and the enthalpy change was found to be -90kJ mol^-1 of magnesium carbonate.

The enthalpy change of the formation of H2O is -285kJ mol^-1 and of CO2 is -393kJ mol^-1. Use this data and your result from above to calculate the enthalpy change of formation of MgCO3."

Can you please talk me through how to do it?


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Open Question: Solar System: Explain the roles of gravity & pressure in the formation of the solar system.?
Open Question: Can explosive events occur in the sky can during the formation of a star?

Open Question: Can explosive events occur in the sky can during the formation of a star?

Your question structure is......difficult to interpret.

A star forms half way across the galaxy. No one may be able to even notice, since the process happens over millions of years. I would have to say that you're not going to see "rockets red glare" and "bombs bursting in air" unless you're willing to sit and wait over a very long time span.


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