how many atoms are in 15.8 g of fe3(po4)2 • if needed, use \e\ for \x10\ (for example, 6.02x1023 will look…

how many atoms are in 15.8 g of fe3(po4)2 • if needed, use \e\ for \x10\ (for example, 6.02x1023 will look like 6.02e23) • no units • leave out the formula -fe3(po4)2 • no spaces round answer to two numbers after the decimal place (0.00)

how many atoms are in 15.8 g of fe3(po4)2 • if needed, use \e\ for \x10\ (for example, 6.02x1023 will look like 6.02e23) • no units • leave out the formula -fe3(po4)2 • no spaces round answer to two numbers after the decimal place (0.00)

Answer

Explanation:

Step1: Calculate molar mass of Fe3(PO4)2

Molar mass of Fe = 55.85 g/mol, P = 30.97 g/mol, O = 16.00 g/mol. Molar mass of Fe3(PO4)2 = 3×55.85+2×(30.97 + 4×16.00)=357.48 g/mol

Step2: Calculate number of moles

Number of moles $n=\frac{m}{M}$, where $m = 15.8$ g and $M = 357.48$ g/mol. $n=\frac{15.8}{357.48}\approx0.0442$ mol

Step3: Calculate number of formula - units

Number of formula - units = $n\times N_A$, where $N_A = 6.022e23$ formula - units/mol. Number of formula - units = $0.0442\times6.022e23 = 2.661724e22$ formula - units

Step4: Calculate number of atoms per formula - unit

In Fe3(PO4)2, there are 3 Fe + 2 P+8 O = 13 atoms per formula - unit

Step5: Calculate total number of atoms

Total number of atoms = number of formula - units×number of atoms per formula - unit Total number of atoms = $2.661724e22\times13=3.4602412e23$ Rounding to two decimal places: $3.46e23$

Answer:

3.46e23