Scelta multipla
How many grams are present in a 2.7 mol sample of CO_2?
115
views
2. Atoms & Elements
Calculating Molar Mass
Scelta multipla
What is the mass, in grams, of 202 atoms of iron (Fe)? (1 mol of Fe has a mass of 55.85 g; Avogadro's number is 6.022 × 10^{23} atoms/mol.)
A
6.73 × 10^{-22} g
B
1.87 × 10^{-20} g
C
5.58 × 10^{-19} g
D
1.12 × 10^{-18} g
Guida verificata passo dopo passo1
Identify the given information: number of iron atoms (202 atoms), molar mass of iron (55.85 g/mol), and Avogadro's number (6.022 \(\times\) 10^{23} atoms/mol).
Calculate the number of moles of iron atoms using the formula: \(\text{moles} = \frac{\text{number of atoms}}{\text{Avogadro's number}} = \frac{202}{6.022 \times 10^{23}}\).
Use the molar mass to find the mass of the given moles of iron: \(\text{mass} = \text{moles} \times \text{molar mass} = \left(\frac{202}{6.022 \times 10^{23}}\right) \times 55.85\) g.
Perform the multiplication and division carefully to maintain the correct order of magnitude and units.
Express the final answer in scientific notation to match the format of the provided options.
Video correlati
Pratica correlata
