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 an electrically neuteral atom, number of protons = number of electrons = atomic number.
Mass number = neutrons + protons/electrons/atomic number
Therefore,
neutrons = mass number - <span>protons/electrons/atomic number
Neutrons = 33 - 15 = 18
The answer is thus B. But this is the solution and explanation along with it as proof.</span>
<span>Soda ash is sodium carbonate, Na2CO3. One chemical property of this compound is its basicity, which is measured by the pKb. The pKb for sodium carbonate is 3.67. It is the result of the dissociation of Na2CO3 in water: Na2CO3 + H2O = Na HCO3 + Na (+) + OH(-). This pKb means that it is a highly basic compound. pKb = log { 1 / [OH-] }, so pKb is a measure of the concentrations of OH- ions, which is the basiciity of the compound. </span>
Rate law for the given 2nd order reaction is:
Rate = k[a]2
Given data:
rate constant k = 0.150 m-1s-1
initial concentration, [a] = 0.250 M
reaction time, t = 5.00 min = 5.00 min * 60 s/s = 300 s
To determine:
Concentration at time t = 300 s i.e. ![[a]_{t}](https://tex.z-dn.net/?f=%5Ba%5D_%7Bt%7D)
Calculations:
The second order rate equation is:
![1/[a]_{t} = kt +1/[a]](https://tex.z-dn.net/?f=1%2F%5Ba%5D_%7Bt%7D%20%3D%20kt%20%2B1%2F%5Ba%5D)
substituting for k,t and [a] we get:
1/[a]t = 0.150 M-1s-1 * 300 s + 1/[0.250]M
1/[a]t = 49 M-1
[a]t = 1/49 M-1 = 0.0204 M
Hence the concentration of 'a' after t = 5min is 0.020 M
