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What are the steps to solving these problems? I don’t need answers, just the steps on how to get the answers.


1. Find the molecular mass of Calcium Citrate.


4. What is the mass of 8.94 x 10^21 molecules of ethanol (C2H5OH)?


5. How many formula units are in 926 g of FeBr3?

Thanks!

Respuesta :

Answer:

1)Molar mass of calcium citrate is 498.46g/mol

4) Mass of [tex]8.94\times 10^{21}[/tex] molecules of ethanol is [tex]68.29\times 10^{-3}g[/tex]

5)926 gm of [tex]FeBr_{3}[/tex] has [tex]18.85\times 10^{23}formula\,units[/tex]

Explanation:

1)

The molecular formula of Calcium citrate- [tex]Ca_{3}(C_{6}H_{5}O_{7})_{2}[/tex]

Let's calculate the molar mass.

[tex]3\times 40g/mol+2((6\times 12)+(5\times1)+(7\times 16))= 498.46g/mol[/tex]

Therefore, molar mass of calcium citrate is 498.46g/mol

4)

One mole of molecule has [tex]6.02\times 10^{23}[/tex] molecules.

Molar mass of ethanol = 46.07 g/mol

[tex]Mass=(8.94\times 10^{21})\times (\frac{1mole}{6.023\times 10^{23}})\times(\frac{46g}{1mole})=68.29\times 10^{-3}g[/tex]

Therefore, mass of [tex]8.94\times 10^{21}[/tex] molecules of ethanol is [tex]68.29\times 10^{-3}g[/tex]

5)

Molar mass of [tex]FeBr_{3}[/tex] = 295.56g/mol

One mole has [tex]6.02\times 10^{23}[/tex] formula units.

Given mass = 926 g

[tex]926 \times \frac{6.023\times 10^{23}\,formula\,units}{295.56}=18.85\times 10^{23}formula\,units[/tex]

Therefore, 926 gm of [tex]FeBr_{3}[/tex] has [tex]18.85\times 10^{23}formula\,units[/tex]