ASAP will give brainliest <3
1. What is the calculated empirical formula of the copper oxide if a 0.626 g sample of the copper oxide was reduced to 0.500 g of copper metal by heating in a stream of hydrogen gas?
2. If a sample of salt water has a measured concentration of 21.0 ppt, how many grams of salt are there in a 2.05 kg sample of this salt water?

because of all the things that happen around the us, many people get into arguments which sadly could get physical, but we should actually make a change for that.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.