Answer:
Pure Chemistry -- is NOT considered a branch of Chemistry.
Explanation:
Second question is number 4.
To determine the concentration of [H+] ions in the solution, it is important that we know the dissociation reaction of the solute. For this case, it would be
HNO3 = H+ + NO3-
Therefore, there is 1:1 ratio between HNO3 and H+ ions. The concentration of the ions would be the same as the solute which is 1.0x10^-4 M.
Problem 1.
1) Grams to mole, for this we need to know molar mass of a substance.
<span>45.7 grams of calcium chloride
</span>calcium chloride is CaCl2
Molar mass (CaCl2) = 40.1 +2*35.5 = 111.1 g/mol
45.7 gram* 1 mol/111.1 g =(45.7/111.1) mol CaCl2
2) reaction
3CaCl2 +Al2O3 -----> 3CaO +2AlCl3
from reaction 3 mol 2 mol
from the problem 45.7/111.1 mol x mol
We have a proportion, so
x= (45.7/111.1)mol*2/3 mol AlCl3
3) Find mass of (45.7/111.1)*2/3 mol AlCl3
Molar mass (AlCl3) = 27.0 +3*35.5= 133.5 g/ mol
((45.7/111.1)*2/3 )*133.5g/1mol= 36.6 g AlCl3
Problem 2.
This problem can be solved the way like the first one.
But both problems can be solved different way.
Second way to solve these problems.
M(Na)=23.0 g/mol,
M(Na2O)= 2*23.0 +16.0= 62.0 g/mol
4Na + O2 -----> 2Na2O
moles from reaction 4mol 2 mol
masses from reaction 4mol*23.0g/1mol 2mol*62.0 g/mol
92 g 124 g
masses from the problem 25.6 g x g
Now, we can write a proportion:
92 g Na produce 124 g Na2O
25.6 g Na produce x g Na2O
92/25.6 = 124/x
x=25.6*124/92= 35.5 g Na2O
Answer:
moles
Explanation:
We are given:
Vapor pressure of water = 19.8 torr
Total vapor pressure = 752 torr
Vapor pressure of oxygen gas = Total vapor pressure - Vapor pressure of water = (752 - 19.8) torr = 732.2 torr
To calculate the amount of oxygen gas collected, we use the equation given by ideal gas which follows:
where,
P = pressure of the gas = 732.2 torr
The conversion of P(torr) to P(atm) is shown below:
So,
Pressure = 732.2 / 760 atm = 0.9634 atm
V = Volume of the gas = 23 mL = 0.023 L
T = Temperature of the gas = ![22^oC=[22+273]K=295K](https://tex.z-dn.net/?f=22%5EoC%3D%5B22%2B273%5DK%3D295K)
R = Gas constant = 
n = number of moles of oxygen gas = ?
Applying the equation as:
0.9634 atm × 0.023 L = n × 0.0821 L.atm/K.mol × 295.15 K
⇒n = moles
