Well a question to ask would be if the mass of the material has changed significantly as that would determine that the substance is radioactive or if there have been any high readings found by a Geiger meter in certain period of time
hope that helps
12.0g x 1 mol / 63.546g = 0.188839581mol
<span>So, for every 1 mole, we have 6.022 x 10^23 of whatever we're measuring. This gives us a conversion factor of (1 mole / 6.022 x 10^23 atoms) or (6.022 x 10^23 atoms / 1 mole).
</span>
0.188839581 mol x (6.022 x 10^23 atoms) / 1 mol = 1.137191955 x 10^23
<span>Remember from before that we are limited to 3 significant figures. Since our calculations are complete, we can now round down to: 1.14 x 10^23 </span>
<span>That should be your answer!
Hope it helps!
xo</span>
Answer:
Vapour pressure of cyclohexane at 50°C is 490torr
Vapour pressure of benzene at 50°C is 90torr
Explanation:
Using Raoult's law, pressure of a solution is defined by the sum of the product sbetween mole fraction of both solvents and pressure of pure solvents.
In the first solution:
<em>(1)</em>
For the second equation:
<em>(2)</em>
Replacing (2) in (1):
-122.5torr = -0.250P°A
<em>Vapour pressure of cyclohexane at 50°C is 490torr</em>
And for benzene:
<em>Vapour pressure of benzene at 50°C is 90torr</em>
The symbol %v/v means percent by volume. Assuming there is no volume effects when these substances are mixed, we calculate as follows:
% v/v = (25 mL ethanol / 25 mL + 150 mL ) x 100
%v/v = 14.29 mL ethanol / mL solution
Hope this answers the question.
Answer:
Is an isotope of Cu (Copper)
Explanation:
Remember that the mass number will tell you the number of protons and neutrons. If you have the mass number(65) and the number of neutrons (36), you just need to subtract: 65 - 36 = 29 the number or protons.
As this is a neutral isotope, that means that is going to have the same number of protons and electrons, that is 29.
