A chemical change affects on the molecular level of matter, which makes it irreversible. Combustion is a pretty good exmple. Physical changes are reversible and dont alter the formula. Hope this helped!
CO2 is Carbon Dioxide and PU is Plutonium
Answer:
V = 0.798 L
Explanation:
Hello there!
In this case, for this gas stoichiometry problem, we first need to compute the moles of carbon dioxide via stoichiometry and the molar mass of starting calcium carbonate:

Next, we use the ideal gas equation for computing the volume, by bearing to mind that the STP conditions stand for a pressure of 1 atm and a temperature of 273.15 K:

Best regards!
Answer:
a) reaction with oxygen
2mg +o2---------2mgo
b) Agno3+NaCl ----------AgCl+NaNo3