Answer:
18 KJ
Explanation:
Data Given:
mass of Lead (m) = 21 g
Heat taken for vaporization (Q) = ?
Solution:
This problem is related to phase change and latent heat of vaporization.
Latent heat of vaporization is the amount of heat taken to convert one mole of substance at its boiling point to its vapor.
So, Latent heat of vaporization of lead has a constant value
Latent heat of vaporization of lead = 177.7 KJ/mol
Formula used
Q = m x Lv. . . . . (1)
where
Lv = specific latent heat of vaporization
here the value for latent heat of vaporization is for mole so instead of mass we will use moles in formula.
So,
Q = no. of mol x Lv. . . . . (2)
first find no. of moles for 21 g of lead
no. of moles = mass in grams / molar mass . . . . . . (3)
molar mass of lead (Pb) = 207 g/mol
put values in equation 3
no. of moles = 21g / 207 g/mol
no. of moles = 0.101 mol
so,
number of moles of lead (Pb) = 0.101 mol
Put values in the eq.2
Q = 0.101 mol x 177.7 KJ/mol
Q = 18 kJ
So, 18KJ of heat is taken to vaporize 21 g of lead (Pb)
Answer:
Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components. A chemical substance is composed of one type of atom or molecule.
Hope this helps :)
When the oxygen atoms in ozone layer were destroyed by ultraviolet radiations the individual oxygen atoms will make bond with each other and form paired oxygen molecules again to form ozone.
What is the ozone layer?
Ozone layer has a high concentration of ozone (O3) in comparison to the rest of the atmosphere, although it is still low in comparison to other gases in the stratosphere.
The ozone layer contains less than ten parts per million of ozone, whereas the normal ozone concentration in the Earth's atmosphere is around 0.3 parts per million. The ozone layer is mostly found in the lower stratosphere.
To learn more about ozone layer click the given link
brainly.com/question/1449495
#SPJ4
3I₂ + 2Al → 2AlI₃
m(I₂)=3M(I₂)m(Al)/{2M(Al)}
m(I₂)=3*253.8*20.4/{2*27.0}=287.64 g
When acids react with water, H ions are released which then combine with water molecules to form H₃O⁺
