25.9 kJ/mol. (3 sig. fig. as in the heat capacity.)
<h3>Explanation</h3>
The process:
.
How many moles of this process?
Relative atomic mass from a modern periodic table:
- K: 39.098;
- N: 14.007;
- O: 15.999.
Molar mass of
:
.
Number of moles of the process = Number of moles of
dissolved:
.
What's the enthalpy change of this process?
for
. By convention, the enthalpy change
measures the energy change for each mole of a process.
.
The heat capacity is the least accurate number in these calculation. It comes with three significant figures. As a result, round the final result to three significant figures. However, make sure you keep at least one additional figure to minimize the risk of rounding errors during the calculation.
<span>the elements in groups1a, 2a, 3a have positive charges according to their group numbers</span>
<span> mass of glucose = 0.055 *165 = 9.075 g
vol of methyl alc = 0.185 * 1.87 = 0.346 L = 346 ml
% NaCl ( m/v ) = mass NaCl * 100/ vol of soln
or Vol of Soln = mass NaCl / % NaCl (m/v)
= 32.1 * 100 / 6 = 535 ml the total vol of soln</span>
Hi , the answer is D because the moon is blocking the sun s rays .
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