if 3.26 g of FeNO33 is dissolved in enough water to make exactly what is the molar concentration of nitrate ion g

0.404M

Explanation:

...To make exactly 100.0mL of solution...

Molar concentration is defined as the amount of moles of a solute (In this case, nitrate ion, NO₃⁻) in 1 L of solution.

To solve this question we need to convert the mass of Fe(NO₃)₃ to moles. As 1 mole of Fe(NO₃)₃ contains 3 moles of nitrate ion we can find moles of nitrate ion in 100.0mL of solution, and we can solve the amount of moles per liter:

Moles Fe(NO₃)₃ -Molar mass: 241.86g/mol-:

3.26g * (1mol / 241.86g) =

0.01348 moles Fe(NO₃)₃ * (3 moles of NO₃⁻ / 1mole Fe(NO₃)₃) =

0.0404 moles of NO₃⁻

In 100mL = 0.1L, the molar concentration is:

0.0404 moles of NO₃⁻ / 0.100L =

0.404M

The answer is b on plato.

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer