Answer:
Forces acting on an object may be balanced or unbalanced. When the forces acting on an object have <u>equal</u> strength and act in opposite directions, they are <u>balanced</u>. These forces cancel out one another, and the <u>motion</u> of the object does not <u>change</u>. When the forces acting on an object are <u>unbalanced</u>, they do not cancel out one another. An unbalanced force acting on an object results in the object’s motion <u>changing</u>. The object may change its <u>speed</u> (speed up or slow
down), or it may change its <u>direction</u>. <u>Friction</u> is a force that resists the motion or the tendency toward motion between two objects in contact with each other. <u>Gravity</u> is a force that pulls objects toward one another. For example, Earth pulls all objects toward it.
Explanation:
Silicon is the element having a mass of 28.09 g
<u>Explanation</u>:
- Silicon is the element having an atomic mass of 28.09 g / mol. So 28.09 g of silicon contains 6.023
10^23 atoms. One mole of each element can produce one mole of compound.
- The Atomic weight of an element can be determined by the number of protons and neutrons present in one atom of that element. So atomic weight expressed in grams always contain the same number of atoms( 6.023 10^23).
- Avagadro number is the number of atoms of 1 mole of any gas at standard temperature and pressure. It has been determined that 6.023 10^23 atoms of an element are equal to the average atomic mass of that element.
Answer:
B-Sucrose molecules are too large to conduct electricity in once dissolved in water.
D-Salts, like NaCL, have ionic bonds and are considered to be electrolytes:when dissolved in water, salts dissociate and form ions.
Explanation:
Answer:
in the periodic table we can see that the ions of Cl is greater than the ions in Na
2.0 L
The key to any dilution calculation is the dilution factor
The dilution factor essentially tells you how concentrated the stock solution was compared with the diluted solution.
In your case, the dilution must take you from a concentrated hydrochloric acid solution of 18.5 M to a diluted solution of 1.5 M, so the dilution factor must be equal to
DF=18.5M1.5M=12.333
So, in order to decrease the concentration of the stock solution by a factor of 12.333, you must increase its volume by a factor of 12.333by adding water.
The volume of the stock solution needed for this dilution will be
DF=VdilutedVstock⇒Vstock=VdilutedDF
Plug in your values to find
Vstock=25.0 L12.333=2.0 L−−−−−
The answer is rounded to two sig figs, the number of significant figures you have for the concentration od the diluted solution.
So, to make 25.0 L of 1.5 M hydrochloric acid solution, take 2.0 L of 18.5 M hydrochloric acid solution and dilute it to a final volume of 25.0 L.
IMPORTANT NOTE! Do not forget that you must always add concentrated acid to water and not the other way around!
In this case, you're working with very concentrated hydrochloric acid, so it would be best to keep the stock solution and the water needed for the dilution in an ice bath before the dilution.
Also, it would be best to perform the dilution in several steps using smaller doses of stock solution. Don't forget to stir as you're adding the acid!
So, to dilute your solution, take several steps to add the concentrated acid solution to enough water to ensure that the final is as close to 25.0 L as possible. If you're still a couple of milliliters short of the target volume, finish the dilution by adding water.
Always remember
Water to concentrated acid →.NO!
Concentrated acid to water →.YES!
