How many moles are 2.54 x 10^29 molecues of H2O

Explanation:

We are asked to convert from molecules of water to moles.

1. Avogadro's Number

1 mole of any substance contains the same number of particles (atoms, molecules, formula units, etc). This is Avogadro's Number: 6.022*10²³. In this problem, the particles are molecules of water.

2. Convert Molecules to Moles

Use Avogadro's Number to make a ratio.

Multiply by the number of molecules given: 2.54 *10²⁹

Flip the ratio so the units of molecules of water cancel.

Condense the problem into 1 fraction.

2.54 *10²⁹ molecules of water are 421, 786.7818 moles of water.

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf   

The correct answer is "hydrogen".