Question #336a1

2 Answers
Jul 31, 2017

5.018xx10^295.018×1029 molecules of H_2OH2O

Explanation:

According to mole concept :

1 mole of H_2H20 = 6.022xx10^236.022×1023 molecules of water = 18 gram H_2H20

So 18 grams of H_2OH2O = 6.022xx10^236.022×1023 no. of molecules H_2OH2O

And

150 grams of H_2OH2O = 6.022xx10^23/"18"xx 1506.022×102318×150 molecules H_2OH2O

= 5.018xx10^295.018×1029 molecules of H_2OH2O

Jul 31, 2017

5.016326 * 10^245.0163261024

Explanation:

To calculate the number of molecules of a substance, we simply multiply the amount of moles by Avogadro's number, which is equal to 6.022 * 10^236.0221023

But how many moles are in 150 g150g of H2OH2O?

Moles = Grams of a substance / Atomic Mass Of A Substance

Moles = 150g150g / 18.01518.015 (The atomic mass of two HH is 2.0162.016. The atomic mass of OO is 15.99915.999)

Moles = 8.33 mol8.33mol

Therefore there are 8.33 * 6.022 * 10^238.336.0221023 molecules. (5.016326 * 10^245.0163261024)