Answer :

The number of moles:
3.15g of [tex]HNO_{3} [/tex]
1 mole of [tex]HNO_{3} [/tex]- 63g.
x moles of [tex]HNO_{3} [/tex]- 3.15g
[tex]x=\frac{1\ mole*3.15g}{63g}=\frac{3.15}{63}=0.05\ mole[/tex]

The number of moles:
19.3 g of NaCl
1 mole of NaCl- 58.44g.
x moles of NaCl- 19.3g.
[tex]x=\frac{1\ mole*19.3g}{58.44g}=\frac{19.3}{58.44}=0.33\ mole[/tex]

The number of moles:
21.25 g of [tex]NaNO_{3} [/tex]
1 mole of [tex]NaNO_{3} [/tex]- 85g.
x moles of [tex]NaNO_{3} [/tex]- 21.25g.
[tex]x=\frac{1\ mole*21.25g}{85g}=\frac{21.25}{85}=0.25\ mole[/tex]

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