How many molecules are there in 42 grams of AIF3

The correct answer is - 3.012×10^23  molecules

Explanation:

The number of molecules is present in any mole of an element or compound are the same. To find the molecules you need to multiply the number of the moles of the compound by Avogadro's number:

Moles are calculated from the molecular weight, for AlF3

= 26.98 + 3×19

= 26.98 + 57

= 83.98

Then moles in 42 grams:

= 42/83.98

= 0.5001190 moles

Now the number of molecules = moles*Avogadro's number

= 0.500110×6.022×10^23

= 3.011×10^23  molecules

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.