To get the answer you use the Law of Raoult.
Raoult's law states that the decrease of the vapor pressure of a liquid is proportional to the molar fraction of the solute.
ΔP = Pa * Xa
Here Pa = 0.038 atm
And Xa = N a / (Na + Nb), where Na is number of moles of A and Nb is number of moles of b
Na = mass of urea / molar mass of urea = 60 g / (molar mass of CH4N2O)
molar mass of CH4N2O = 12 g/mol + 4*1g/mol + 2*14 g/mol + 16 g/mol = 60 g/mol
Na = 60 g / 60 g/mol = 1 mol
Nb = mass of water / molar mass of water = 180g / 18g/mol = 10 mol
Xa = 1 mol / (10 mol + 1 mol) = 1/11 =0.09091
ΔP = Pb * Xa = 0.038 atm * 0.09091 = 0.0035 atm
Then, the final vapor pressure of water is Pb - ΔP = 0.038atm - 0.0035atm = 0.035 atm.
Answer: 0.035 atm
1.51 x 10²⁵atoms
Explanation:
Given parameters:
Mass of Na = 578g
Unknown:
Number of atoms = ?
Solution:
To find the number of atoms, we must first find the number of moles the given mass contains.
Number of moles = 
molar mass of Na = 23g
Number of moles = 
= 25.13moles
1 mole of a substance = 6.02 x 10²³atoms
25.13 mole of Na = 25.13 x 6.02 x 10²³atoms
This gives 1.51 x 10²⁵atoms of Na
Learn more:
Avogadro's constant brainly.com/question/2746374
#learnwithBrainly
A. A pure chemical substance consisting of one type of atom
Answer: 1.2642*10²⁵ on both sides
Explanation:
First check how many moles are there on each side.
Since this is a balanaced equataion the number of moles on each side is the same thus the number of atoms is also same on both sides
There are 3 moles of carbon and 8 moles of hydrogen in C3H8
and 2 moles of oxygen in O2 but there 5 infront so 2*5 is 10
Number of moles on the right is 10+8+3 = 21
Now use Avogrado's constant
21 Moles* (6.02*10²³)/Mol
= 21*6.02*10²³
= 1.2642*10²⁵
Answer:
Explanation:
When going from top to bottom in any group of the periodic table, the atomic radius always tends to increase
