A chemist performs the following reaction: PCl5 (aq) + 4H2O (l) ⟶ H3PO4 (aq) + 5HCl (aq)
If she has 26.4 g of PCl5, what mass of water should she react to use up all of the
PCl5?

Looking for an in-depth step by step, please

9.17 g

Explanation:

1) Calculate mols of PCl5

PCl5 (aq) + 4H2O (l) ⟶ H3PO4 (aq) + 5HCl (aq)

Mass of PCl5: 26.5g

Molar Mass of PCl5 208.24g/mol

Mol of PCl5 = Mass PCl5 /Molar mass PCl5  = 26.5g / (208.24g/mol) = 0.127257011 mol

2) Calculate mols of water needed to react

Mols of H2O per 1 Mols of PCl5 = 4 (because 4 water is needed to Phosphorus pentachloride).

Mols of H2O = Mol of PCl5 * 4 = 0.127257011 * 4 = 0.509028044 mols

3) Calculate Grams of water needed to react

Mols of H2O = 0.509028044 mols

Molar Mass of H2O = 18.015 g/mol

Mass of H2O = Mols of H2O * Molar Mass of H2O

= 0.509028044 mols* 18.015 g/mol = 9.17014021 g

sf = 3

9.17 g

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.