Water containing more than 3.0 grains of dissolved solids per gallon is considered to be hard [1 grain (gr) = 64.8 mg]. So, if a kettle contains 18 gal of tap water, which is allowed to evaporate. The solid material left behind has a mass of 1.7 g. Is such tap water considered to be hard?

Explanation:

The solid material left behind, after the 18 gal of tap water was evaporated, is the amount of dissolved solids in that quantity of water.

You must convert the amount in grams (1.7g) into grains:

That is in 18 gallons. Then, divide by 18 gal to obtain the number of grains dissolved per gallon:

That is much greater than 3.0 grains per gallon; thus, such tap water is considered to be hard.

n+h→nh3

we must remember that nitrogen and hydrogen are both diatomic molecules in their standard gas form. this adjusts the equation to

n2+h2→nh3

now we need to adjust coefficients in order to balance the atoms on each side of the equation. currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.

we can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.

n2+3h2→2nh3

this gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.

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.