Answer to Question #101951 in Chemistry for Catelynn

Question

How many formula units are in 7.9 moles of lithium fluoride?
*Give your answer using scientific notation and no spaces. For example 6.02x10^23 or 8.96x10^24
*Round to the appropriate number of Significant Figures*

How many molecules are in 15 moles of carbon dioxide?
*Give your answer using scientific notation and no spaces. For example 6.02x10^23 or 8.96x10^24
*Round to the appropriate number of Significant Figures*

Convert 3.050x10^38 atoms of Iron to moles.
*Rounded to the HUNDREDTH*

Convert 1.20x10^24 formula units of NaCl to moles.
*Rounded to the HUNDREDTH*

Convert 6.02x10^22 molecules of Br2 to moles.
*Rounded to the HUNDREDTH*

Convert 1.00x10^9 formula units of PbO2 to moles.
*Rounded to the HUNDREDTH*

Answer 1

N (LiCl) = 7.9 mol × 6.02 × 10²³ = 47.558 × 10²³ = 4.8 × 10²⁴ of LiCl formula units

N(CO₂) = 15 mol × 6.02 × 10²³ = 90.3 × 10²³ = 9.0 × 10²⁴ of CO₂ molecules

n (Fe) = 3.050 × 10³⁸ / 6.02 × 10²³ = 0.506644518 × 10¹⁵ = 5.07 × 10¹⁴ mol of Iron

n (NaCl) = 1.20 × 10²⁴ / 6.02 × 10²³ = 0.1993355 × 10¹ = 1.99 mol of NaCl formula units

n (Br₂) = 6.02 × 10²² / 6.02 × 10²³ = 1.00 × 10^-1 mol of Br₂ molecules

n (PbO2) = 1.00 × 10⁹ / 6.02 × 10²³ = 0.166113 × 10^-14 = 1.66 × 10^-15 mol of PbO₂ formula units