Question

question 11
428 mols of mg are equal to 2.58×10²⁶ atoms of mg
blank 1 428
question 12
2.04×10^23 atoms are found in a sample contains 2.54 grams of c₆h₁₂o₆
blank 1 2.04
blank 2 23

Explanation:

Step1: Identify given values for Question 11

Given 2.58×10²⁶ atoms of Mg.

Step2: Recall Avogadro's number

Avogadro's number \(N_A = 6.022\times 10^{23}\text{ atoms/mol}\).

Step3: Calculate moles of Mg

Use formula \(n=\frac{N}{N_A}\), where \(N\) is number of atoms and \(n\) is number of moles. So \(n=\frac{2.58\times 10^{26}}{6.022\times 10^{23}}\approx428\) moles.

Step4: Identify given values for Question 12 - mass

Given mass of \(C_6H_{12}O_6\) is \(m = 2.54\) g.

Step5: Calculate molar - mass of \(C_6H_{12}O_6\)

\(M=(6\times12.01 + 12\times1.01+6\times16.00)\text{ g/mol}=180.18\text{ g/mol}\).

Step6: Calculate moles of \(C_6H_{12}O_6\)

Use formula \(n=\frac{m}{M}\), so \(n=\frac{2.54}{180.18}\text{ mol}\approx0.0141\) mol.

Step7: Calculate number of molecules of \(C_6H_{12}O_6\)

Use \(N = n\times N_A\), \(N=0.0141\times6.022\times 10^{23}\text{ molecules}\approx8.49\times 10^{21}\text{ molecules}\).

Step8: Calculate number of atoms in \(C_6H_{12}O_6\)

One molecule of \(C_6H_{12}O_6\) has \(6 + 12+6=24\) atoms. So number of atoms \(=8.49\times 10^{21}\times24 = 2.04\times 10^{23}\) atoms.

Answer:

Question 11 Blank 1: 428
Question 12 Blank 1: 2.04
Question 12 Blank 2: 23