Answer:
The correct answer is 281.39 grams.
Explanation:
To arrive at this answer you must first keep in mind the basic equation:
<em>Q = m*Cp* ΔT</em>
Now, in order to calculate the necessary aluminum mass that absorbs 2138 J when passing from 14.83 to 23.31 ° C you must "clear" <em>m</em> of the previous equation.
This means, leave only the mass on one side of the equation, and "pass" <em>Cp</em> and <em>ΔT</em> to the other side dividing <em>Q</em>. This would look like this:
m= Q/ (Cp*ΔT)
Then, <u>you need the value of specific heat of aluminum</u> in the correct units, that is J / g ° C, the approximate value is 0.896.
ΔT is calculated by doing the mathematical operation:
23.31 °C - 14.83 °C = 8.48 °C
<em>
Finally, the values of: Q (data provided in joules), Cp (J / g ° C) and ΔT (calculated in ° C) are replaced in the last equation and the mass (in grams) is calculated resulting in 281.39 grams.</em>
Answer:Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ).
Explanation:
77.
To find the answer u have to subtract the atomic mass from the atomic number.
Answer:
SO42 - Trigonal planar ion
Explanation:
The SO4^2- ion is tetrahedral and not trigonal planar because the sulphur atom has four regions of electron density which includes the lone pair of electrons on sulphur atom.
This accounts for the observed tetrahedral arrangement of electron pairs around the central sulphur atom in SO4^2- ion, hence the answer.
