Question

enter or select the correct answer for each question. you may take this quiz once.
question (partially obscured) 1 pts
how many mol are in 5.44 x 10²⁴ atoms of au? write your answer to three significant figures.
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question 2 1 pts
how many grams of mo are in 0.287 mol of mo? write your answer to three significant figures.
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Explanation:

Question 1

Step1: Recall Avogadro's number

Avogadro's number is \( 6.022 \times 10^{23} \) atoms/mol. To find moles from atoms, use the formula \( n=\frac{N}{N_A} \), where \( N \) is the number of atoms and \( N_A \) is Avogadro's number.

Step2: Substitute values

\( N = 5.44\times 10^{24} \) atoms, \( N_A=6.022\times 10^{23} \) atoms/mol. So \( n=\frac{5.44\times 10^{24}}{6.022\times 10^{23}} \)

Step3: Calculate

\( \frac{5.44\times 10^{24}}{6.022\times 10^{23}}=\frac{5.44}{6.022}\times 10^{24 - 23}\approx0.903\times 10^{1}=9.03 \) mol (to three significant figures)

Step1: Recall molar mass of Mo

Molar mass of Mo (molybdenum) is \( 95.95 \) g/mol (from periodic table). The formula to find mass \( m = n\times M \), where \( n \) is moles and \( M \) is molar mass.

Step2: Substitute values

\( n = 0.287 \) mol, \( M = 95.95 \) g/mol. So \( m=0.287\times95.95 \)

Step3: Calculate

\( 0.287\times95.95\approx27.5 \) g (to three significant figures)

Answer:

\( 9.03 \)

Question 2