How many grams of nacl are contained in 0.50 l of a 4.20 m solution?

58.44 g nacl

245.5 g nacl

122.7 g nacl

173.6 g nacl

The answer to your question is the third option: 122.7 g of NaCl

Explanation:

Data

mass of NaCl = ?

molecular mass of NaCl = 23 + 35.5 = 58.5

volume = 0.50 l

concentration = 4.20 M

Formula

     Moles = Molarity x volume

Process

1.- Substitute the data given to find the moles of NaCl

     Moles = 4.20 x 0.5

     Moles = 2.1

2.- Calculate the grams of NaCl using proportions

     58.5 g of NaCl ----------------- 1 mol

        x                     ----------------  2.1 moles

      x = (2.1 x 58.5) / 1

3.- Result

      x = 122.7 g of NaCl      

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.

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