<span>Atoms move at different speeds depending on whether they are in liquids or solids </span><span>because the atoms or particles in solids are closely bonded while they are loosely bonded in liquids.
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</span><span>The attractive forces between the particles are so high that they remain in fixed positions. The particles, then, cannot slip over the neighbors particles. They can only vibrate. That is why solids have definite form and volume.</span><span />
<span>That the particles in liquids are loosely bonded means that the attractive forces are less compared with solids. Then the partilces can move and pass each other. They are not in fixed arrangements any more. Yet the particles are attracted to each other, so they have definite volume, although they take the form of the vessel, and they can flow.
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Answer : Unit of any measurement can be defined as a definite magnitude of a given quantity, which is defined and adopted by convention or by law, that is widely used as a standard for measurement of the same kind of quantity. If the unit system was not given to the measurements we would haphazardly complicate the calculations.
Example : If someone wrote 500 in the paper as a answer to a question. But forgot to mention the units of the measurements. It can be misinterpreted by anyone as there are no units written besides the number (unit less). Complications grow. One cannot simply predict is it 500 m? 500 g? 500 mL? 500 km? 500 s? or 500 M? anything can be guessed. To be specific about the answer to any problem we should always use units. Which will help to narrow down the approach of any problem and give a measurable related quantity about the associated problem.
Answer:
a. 1.728 moles.
b. 262.7g of Cr₂O₃ are required
Explanation:
Based on the reaction:
Cr₂O₃(s) + 3H₂S(g) → Cr₂S₃(s) + 3H₂O(l)
The important thing in the reaction is that 1 mole of Cr₂O₃ produce 1 mole of Cr₂S₃
a. To produce 346g of Cr₂S₃ we must know how many moles of Cr₂S₃ must be produced, and, as 1 mole of Cr₂O₃ produce 1 mole of Cr₂S₃ we can know moles of Cr₂O₃ that are required.
<em>Moles of 346g Cr₂S₃ (Molar mass: 200.19g/mol):</em>
346g Cr₂S₃ * (1mol / 200.19g) = 1.728 moles of Cr₂S₃
Based on the reaction, moles of Cr₂O₃ that are required are
<h3>
1.728 moles of Cr₂O₃</h3>
b. Again, to conver the 1.728 moles of Cr₂O₃ to grams we must use molar mass of Cr₂O₃ (151.99g/mol):
1.728 moles Cr₂O₃ * (151.99g / mol) =
<h3>262.7g of Cr₂O₃ are required</h3>