Isobaric transition, first law: <span>H=ΔU+w</span>
for a gas expansion: <span>w=<span>P<span>ext</span></span>∗ΔV</span>
to convert to joules, you need the gas constants.
R = 0.08206 L atm/mol*K, R=8.314 J/mol*K
<span>w=<span>P<span>ext</span></span>∗ΔV∗<span><span>8.314 J/mol∗K</span><span>0.08206 L atm/mol∗K</span></span></span>
<span>ΔU=ΔH−[<span>P<span>ext</span></span>∗ΔV∗<span><span>8.314 J/mol∗K</span><span>0.08206 L atm/mol∗K</span></span>]</span>
<span>ΔU=−75000 J−[(43.0atm)∗(2−5)L∗<span><span>8.314 J</span><span>0.08206 L atm</span></span>]</span>
Then you need to convert to kJ.
by the way U=E, internal energy.
The answer is 267.93 g
Molar mass of CaBr2 is the sum of atomic masses of Ca and Br:
Mr(CaBr2) = Ar(Ca) + 2Ar(Br)
Ar(Ca) = 40 g/mol
Ar(Br) = 79.9 g/mol
Mr(CaBr2) = 40 + 2 * 79.9 = 199.8 g/mol
The percentage of Br in CaBr2 is:
2Ar(Br) / Mr(CaBr2) * 100 = 2 * 79.9 / 199.8 * 100 = 79.98%
Now make a proportion:
x g in 79.98%
335 g in 100%
x : 79.98% = 335 g : 100%
x = 79.98% * 335 g : 100%
x = 267.93 g
Elements are substances that contain only 1 kind of atom.
Explanation:
Let us take the volume of block is x.
Since, the block is floating this means that it is in equilibrium. Formula to calculate net force will be as follows.
Also, buoyancy force 
= (volume submerged in water × density of water) + (volume in oil × density of oil)
= 
= 
g
As, W = V × density of graphite × g
It is given that density of graphite is 
or 2160 
.
So, W = 2160 V g
= (0.592 V \rho + 408 V) g - 2160 V g = 0
= 1752
= 2959.46 or 2.959 
is the density of oil.
It is given that mass of flask is 124.8 g.
Mass of 35.3 
oil = 
104.7 g
Hence, in second weighing total mass will be calculated as follows.
(124.8 + 104.7) g
= 229.27 g
Thus, we can conclude that in the second weighing mass is 229.27 g.
In a neutral atom they are both equal, and their even quantities makes the atom neutral...
