Answer:
Molarity: 6.2x10⁻³M NaCl
Molality: 6.2x10⁻³m NaCl
Mole Fraction: 1.1x10⁻⁴
Mass% NaCl: 0.036% (m/m NaCl)
Explanation:
<em>Molarity -Moles NaCl / L-</em>
<em>Moles NaCl -Molar mass: 58.44g/mol-</em>
0.018g * (1mol/58.44g) = <em>0.000308 moles NaCl</em>
<em>Liters water:</em>
50mL * (1L/1000mL) = <em>0.050L</em>
M = 0.000308 moles NaCl / 0.050L
<h3>M = 6.2x10⁻³M NaCl</h3><h3 />
<em>Molality -Moles NaCl / kg water-</em>
<em>Moles NaCl = 0.000308 moles NaCl</em>
<em>kg water = 50mL * (1g/mL) * (1kg/1000g) = 0.050kg</em>
m = 0.000308 moles NaCl / 0.050kg
<h3>m = 6.2x10⁻³m NaCl</h3><h3 />
<em>Mole Fraction -Moles NaCl / Moles water+ Moles NaCl-</em>
<em>Moles water = 50g * (1mol/18.01g) = 2.776 moles</em>
Moles fraction = 0.000308 moles NaCl / 0.000308 moles NaCl + 2.776moles water
<h3>Mole fraction = 1.1x10⁻⁴</h3><h3 />
<em>Mass Percent -Mass NaCl / Mass NaCl+Mass Water * 100</em>
0.018g / 50g+0.018g * 100
<h3>0.036% (m/m NaCl)</h3>
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