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Problem 36 Medium Difficulty

Identify each substance as a molecular compound or an
ionic compound, and then calculate its molar mass.
\begin{equation}a . {Sr}\left(\mathrm{NO}_{3}\right)_{2}\end{equation}
\begin{equation}b. \left(\mathrm{NH}_{4}\right)_{3} \mathrm{PO}_{4}\end{equation}
\begin{equation}\mathbf{c} . \mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\end{equation}


a. ionic compound, 212 $\mathrm{g}$
b. ionic compound, 149 $\mathrm{g}$
c. molecular compound, 342.3 $\mathrm{g}$


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Video Transcript

strontium nitrate is nine. A compound well, like a strong team, is a medal, and we recognize nitrate is a poly atomic eye on. And so to calculate, the molar mass. We treated it as any other compound got one mole of strontium. That's 87.62 grams per mole. We have two moles of nitrogen. That's 14 point no. One grams per mole, and then we have six moles of oxygen, right? There are two nitrate ions and each night trade on his three oxygen. So six times 16 grams promote. It's gonna have a 64 grams of oxygen. You add those three numbers up, and that will give you the molar mass of the compound 179.64 grams per mole. Ammonium phosphate is another ionic compound. You've got to recognize the ammonium ion and the phosphate eye on an air ammonium with one plus charged phosphate with three minus charge. So calculating the molar Mass. Three Moles of nitrogen times 14.1 grams per mole. They're 12 moles of hydrogen, 1.1 grams per mole. There's one mole of phosphorus that's 30.97 grams per mole. And then there are four moles of oxygen at 16 grams per mole. Remember, find the molar mass of the Adams on the periodic table. And once we get these four numbers were gonna Adam all up to get the molar mass of this ionic compound ammonium phosphate and you get 100 and 49.12 grams per mole. This is a molecular compound because it is only made of non metals, we still calculate the molar mass the same way there 12 moles of carbon. So they're 12 point and one grams per mole. So we have 100 and 44.12 grams of carbon. In this compound. There are 22 moles of hydrogen at 1.1 grams per mole. So 22 point 22 grams of hydrogen in this compound. Then there are 11 moles of oxygen. At 16 grams per mole, we get 100 and 76 grams of oxygen in here. Add those numbers up. 342.34 grams per mole. A similar mass of secrets