Answer:
Q = 143,921 J = 143.9 kJ.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the absorbed heat by considering this is a process involving sensible heat associated to the vaporization of water, which is isothermic and isobaric; and thus, the heat of vaporization of water, with a value of about 2259.36 J/g, is used as shown below:

Thus, we plug in the mass and the aforementioned heat of vaporization of water to obtain the following:

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A. The bonds between the individual monomers of a polymer are broken by the addition of water molecules.
Answer:
~69.744 moles of Ca
Explanation:
Using Avogadro's constant , we know that:
1 mole = 6.022 x 10^23 atoms
S0, the number of moles in 4.20 x 10^25 atoms of Ca:
=(4.20 x 10^25 x 1 )/(6.022 x 10^23)
~69.744 moles of Ca
Q2:How many atoms are in 0.35 moles of oxygen?
1 mole = 6.022 x 10^23 atoms
S0, the number of atoms in 0.35 moles of oxygen:
=[0.35 x (6.022 x 10^23)]
=2.1077 x 10^23 atoms of Oxygen
Hope it helps:)
Answer:
Take approx 41.7 mL of 12-M HCl in a 1.00-L flask and fill the rest of the volume with distilled water.
Explanation:
Hello,
In this case, for the dilution process from concentrated 12-M hydrochloric acid to 1.00 L of the diluted 0.50M hydrochloric acid, the volume of concentrated HCl you must take is computed by considering that the moles remain constant for all dilution processes as shown below:

Which can also be written in terms of concentrations and volumes:

Thus, solving for the initial volume or aliquot that must be taken from the 12-M HCl, we obtain:

It means that you must take approx 41.7 mL of 12-M HCl in a 1.00-L flask and fill the rest of the volume with distilled water for such preparation.
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