Answer: (1). There are 0.0165 moles of gaseous arsine (AsH3) occupy 0.372 L at STP.
(2). The density of gaseous arsine is 3.45 g/L.
Explanation:
1). At STP the pressure is 1 atm and temperature is 273.15 K. So, using the ideal gas equation number of moles are calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = number of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
2). As number of moles are also equal to mass of a substance divided by its molar mass.
So, number of moles of Arsine 
(molar mass = 77.95 g/mol) is as follows.
Density is the mass of substance divided by its volume. Hence, density of arsine is calculated as follows.
Thus, we can conclude that 0.0165 moles of gaseous arsine (AsH3) occupy 0.372 L at STP and the density of gaseous arsine is 3.45 g/L.
Chlorofluorocarbons are a class of organic compounds that were used as propellants in the late 20th century. The problem with CFC's is that they attack the ozone layer, breaking it down. The weakened ozone layer is not able to stop UV light from reaching the earth, so the amount of UV light reaching the earth increases. This results in increased temperatures, and the death of vegetation.
Therefore, the answer is B.
Answer:
Volume of NaOH required = 3.61 L
Explanation:
H2SO3 is a diprotic acid i.e. it will have two dissociation constants given as follows:
--------(1)
where, Ka1 = 1.5 x 10–2 or pKa1 = 1.824
--------(2)
where, Ka2 = 1.0 x 10–7 or pKa2 = 7.000
The required pH = 6.247 which is beyond the first equivalence point but within the second equivalence point.
Step 1:
Based on equation(1), at the first eq point:
moles of H2SO3 = moles of NaOH
Step 2:
For the second equivalence point setup an ICE table:
Initial 1.98 ? 0
Change -x -x x
Equil 1.98-x ?-x x
Here, ?-x =0 i.e. amount of OH- = x
Based on the Henderson buffer equation:
![pH = pKa2 + log\frac{[SO3]^{2-} }{[HSO3]^{-} } \\6.247 = 7.00 + log\frac{x}{(1.98-x)} \\x=0.634 moles](https://tex.z-dn.net/?f=pH%20%3D%20pKa2%20%2B%20log%5Cfrac%7B%5BSO3%5D%5E%7B2-%7D%20%7D%7B%5BHSO3%5D%5E%7B-%7D%20%7D%20%5C%5C6.247%20%3D%207.00%20%2B%20log%5Cfrac%7Bx%7D%7B%281.98-x%29%7D%20%5C%5Cx%3D0.634%20moles)
Volume of NaOH required is:
Step 3:
Total volume of NaOH required = 3.22+0.389 =3.61 L
The answer is a. a homogenous mixture
Answer:
The streak of a mineral is the color of the powder produced when it is dragged across an un-weathered surface
Explanation:
it's simple
