This is what I got. Hope it helps :)
Length of 1 side 1.2*10^-5km =1.2*10^-5*10^5 =1.2cm
<span>volume of the cube (1.2)^3=1.728 cm^3 </span>
<span>density= mass/volume= 1.1/1.728=0.636 g/cm^3</span>
From the periodic table:
mass of carbon = 12 grams
mass of hydrogen = 1 gram
mass of chlorine = 35.5 grams
Therefore,
molar mass of CH2Cl2 = 12 + 2(1) + 2(35.5) = 85 grams
number of moles = mass / molar mass
number of moles of CH2Cl2 = 66.05 / 85 = 0.777 moles
One mole of CH2Cl2 contains two moles of Cl and each chlorine mole has Avogadro's number of atoms in it.
Therefore,
number of chlorine atoms in 0.777 moles of CH2Cl2 can be calculated as follows:
number of atoms = 0.777 * 2 * 6.022 * 10^23 = 9.358 * 10^23 atoms
Now, we will take log base 10 for this number:
log (9.358 * 10^23) = 23.97119
Answer:
<u>Heating water with an open flame</u>
<u>Explanation:</u>
Remember, we are told in the label that Acetone is a "flammable liquid and vapor." <em>Being flammable means the substance can easily be set on fire</em>, and we would expect an open flame from heating water to trigger an explosion (a disaster) in which the Acetone is set on fire causing life-threatening dangers to the second group of students.
Answer: The mass percentage of 
is 5.86%
Explanation:
To calculate the mass percentage of in the sample it is necessary to know the mass of the solute ( in this case), and the mass of the solution (pesticide sample, whose mass is explicit in the letter of the problem).
To calculate the mass of the solute, we must take the mass of the 
precipitate. We can establish a relation between the mass of and using the stoichiometry of the compounds:
Since for every mole of Tl in there are two moles of Tl in , we have:
Using the molar mass of we have:
Finally, we can use the mass percentage formula:
