Question

If 16 grams of sugar, C12H22O11, are in a spoonful, how many molecules of sugar are in the spoonful?

Answer 1

Answer:

If 16 grams of sugar are in a spoonful, 2.83*10²² molecules of sugar are in the spoonful

Explanation:

Avogadro's Number or Avogadro's Constant is the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of that substance. Its value is 6.023 * 10²³ particles per mole. The Avogadro number applies to any substance.

So you need to know how many moles are 16 grams of sugar, C₁₂H₂₂O₁₁. For that you must know the molar mass of sugar. Being:

• C: 12 g/mole
• H: 1 g/mole
• O: 16 g/mole

the molar mass of sugar is:

C₁₂H₂₂O₁₁= 12 *12 g/mole + 22 * 1 g/mole + 11* 16 g/mole= 342 g/mole

Then the following rule of three applies: if 342 grams of sugar are present in 1 mole of substance, 16 grams in how many moles will they be?

$moles=\frac{16 grams*1 mole}{342 grams}$

moles= 0.047

Now, knowing Avogadro's number, you can apply the following rule of three: if 1 mole of sugar contains 6.023 * 10²³ molecules, 0.047 moles how many molecules does it have?

$molecules=\frac{0.047 moles*6.023*10^{23} }{1 mole}$

molecules= 2.83*10²²

If 16 grams of sugar are in a spoonful, 2.83*10²² molecules of sugar are in the spoonful

Answer 2

Answer:

2.82x10^22 molecules.

Explanation:

From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02x10^23 molecules.

The above hypothesis implies that 1 mole of sugar, C12H22O11 also contains 6.02x10^23 molecules.

1 mole of C12H22O11 = (12x12) + (22x1) + (16x11) = 144 + 22 + 176 = 342g

Now, if 342g of C12H22O11 contains 6.02x10^23 molecules,

Therefore 16g of C12H22O11 will contain = (16x6.02x10^23)/342 = 2.82x10^22 molecules.

Therefore, 2.82x10^22 molecules of the sugar are in the spoon