Ascientist conducts a chemical reaction. at the beginning of the reaction, she combines 5.4 grams of the first reactant and 6.3 grams of the second reactant. she runs the reaction in a closed chamber and heats only the reaction. a small amount of gas is produced. what can you conclude about the total mass of the substances present when the reaction is complete?

If it's in a closed chamber, the gas would not escape and the products would weigh the same as the reactant before the reaction since law of conservation of matter would take place. However, there might be an insignificant loss of the product since its difficult to measure the weight of the product in such reaction.

Explanation:

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.