I don’t know if this is right but I thing It’s B
Water is one of the few substances which expand in volume when frozen, compared to liquid. Usually substances condense when cooled, but at the point of freezing, when liquid water becomes solid ice, the molecules lock into a matrix in which there is more space between molecules - ice expands! This is why ice floats on liquid water.
It is this miracle which has shaped the planet and allowed life to thrive. Expansion of ice is responsible for much land-shaping erosion on land, the heaving off of boulders from mountain tops. And the floating of ice on lakes, rivers and oceans - if the frozen water was indeed more dense than liquid water, it would sink and pile up in the cold depths. There would be no life thriving under the ice, overwintering. It would all eventually freeze solid, and all the life forms with it.
Answer:
the atomic mass of any elemet contains avogardo numberof atoms
In case of Gallium,
69.72 gram is atomic mass and it cotnains around 6.023*10^23 atoms of Gallium
but, 2000 punds = 907184.7 grams
907184.7 gram of gallium contains= 6.023*10^23* 907184/69.72
= 79 *10^26 atoms
Explanation:
Answer:
(a)
(b)
Explanation:
Hello,
(a) In this case, as the reaction is second-ordered, one uses the following kinetic equation to compute the concentration of NOBr after 22 seconds:
![\frac{1}{[NOBr]}=kt +\frac{1}{[NOBr]_0}\\\frac{1}{[NOBr]}=\frac{0.8}{M*s}*22s+\frac{1}{0.086M}=\frac{29.3}{M}\\](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5BNOBr%5D%7D%3Dkt%20%2B%5Cfrac%7B1%7D%7B%5BNOBr%5D_0%7D%5C%5C%5Cfrac%7B1%7D%7B%5BNOBr%5D%7D%3D%5Cfrac%7B0.8%7D%7BM%2As%7D%2A22s%2B%5Cfrac%7B1%7D%7B0.086M%7D%3D%5Cfrac%7B29.3%7D%7BM%7D%5C%5C)
![[NOBr]=\frac{1}{29.2/M}=0.0342M](https://tex.z-dn.net/?f=%5BNOBr%5D%3D%5Cfrac%7B1%7D%7B29.2%2FM%7D%3D0.0342M)
(b) Now, for a second-order reaction, the half-life is computed as shown below:
![t_{1/2}=\frac{1}{k[NOBr]_0}](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%3D%5Cfrac%7B1%7D%7Bk%5BNOBr%5D_0%7D)
Therefore, for the given initial concentrations one obtains:
Best regards.
