Although the data is not stated, the standard enthalpy of formation of ammonia is -46 kJ/mol.
The standard enthalpy of formation of a substance is the change in enthalpy that occurs when one mole of that substance is produced from its elements in their standard states. The fact that the standard enthalpy of formation for ammonia is negative indicates that the formation of ammonia is an exothermic, or energy releasing, reaction.
Answer:

Explanation:
To convert from moles to grams, we must use the molar mass.
Recall that water's molecular formula is H₂O. It contains hydrogen and oxygen. Look up the two elements masses on the Periodic Table.
- Hydrogen (H): 1.008 g/mol
- Oxygen (O): 15.999 g/mol
Now, use these masses to find water's mass. The subscript of 2 tells us there are 2 atoms of hydrogen, so we multiply hydrogen's mass by 2 and add oxygen's.
- H₂O= 2(1.008 g/mol) + 15.999 g/mol = 18.015 g/mol
Use the molar mass as a ratio.

Multiply by the given number of moles.

The moles of water will cancel.



Round to the nearest whole number. The 0 in the tenth place tells us to leave the number as is.

There are about <u>54 grams</u> of water in 3 moles.
In a solid state, the molecules have the least amount of energy. They just stick close together and vibrate in place. As the molecules gain more energy, they are able to move around more freely. In the liquid state, the molecules have enough energy to sort of tumble over each other.
Answer:
Double decomposition reaction
Explanation:
When hydrochloric acid reacts with any carbonates/hydrogen carbonates the products formed are metal chloride , water and carbon dioxide.Since HCl decomposes salts of weaker acids.
So the equation of the reaction between calcium carbonate and HCl is:
CaCO3+2HCl =CaCl2+H2O+CO2
This reaction is also known as double decomposition reaction.
Arrhenius theory is a theory about acids and bases. It says that acids are those substances that produces hydrogen ions (H+) when in solution and bases are the substances that dissiociates and produces hydroxide ions (OH-). It was introduced by Svante Arrhenius.