Question

Help me answe step by step please covert 9 molecules of glucose to grams

Answer 1

2.690 x 10⁻²¹ g of glucose (C6H12O6).

Step-by-step explanation:

We want to find the mass in grams of 9 molecules of glucose, so we have to use Avogadro's number, which is 6.022 x 10²³ molecules/mol. This number is telling us that there are 6.022 x 10²³ molecules or units in 1 mol of any substance.

We can state a rule of three to do this. If 1 mol contains 6.022 x 10²³ molecules, how many moles will contain 9 molecules?

As we have 9 molecules of glucose (C6H12O6), the conversion from molecules to moles will look like this:

`9\text{ molecules glucose}\cdot\frac{1\text{ mol glucose}}{6.022\cdot10^(23)\text{ molecules glucose}}.`

Now, let's calculate the molar mass of C6H12O6 using the periodic table. You can see that the molar mass of C is 12 g/mol, the molar mass of H is 1 g/mol and the molar mass of O is 16 g/mol. We have six C, twelve H, and six O, so we have to do an algebraic sum to find the molar mass of C6H12O6, as follows:

`\begin{gathered} Mola\text{r mass of C}_6H_(12)O_6=6\cdot12(g)/(mol)+12\cdot1(g)/(mol)+6\cdot16(g)/(mol), \\ \\ Mola\text{r mass of C}_6H_(12)O_6=72(g)/(mol)+12(g)/(mol)+96(g)/(mol), \\ \\ Mola\text{r mass of C}_6H_(12)O_6=180(g)/(mol). \end{gathered}`

So the molar mass of glucose (C6H12O6) is 180 g/mol. This is telling us that we have 180 g of glucose in 1 mol of glucose.

We can state a rule of three again to find the mass of glucose. Previously we found that we have 9/6.022 x 10²³ moles of glucose in 9 molecules of glucose and we want to find how many grams are in 9/6.022 x 10²³ moles of glucose:

So the calculation and its answer will look like this:

`\frac{9\text{ moles glucose}}{6.022\cdot10^(23)}\cdot\frac{180\text{ g glucose}}{1\text{ mol glucose}}=2.690\cdot10^(-21)\text{ g glucose.}`

The answer would be that we have 2.690 x 10⁻²¹ g of glucose (C6H12O6) in 9 molecules of glucose.