Number #2 is joule
In the SI system the unit of heat is the joule. The calorie was defined so that the heat capacity of water was equal to one.The heat capacity of a substance is the amount of heat required to raise the temperature of a defined amount of pure substances by one degree.
Number #3 is Endothermic
Why? I can't explain. I Just left class where they were just explaining that.
Molar mass
C₂H₄O₂ = 60.0 g/mol
n = mass / molar mass
3.00 = mass / 60.0
m = 3.00 * 60.0
m = 180 g of <span>C₂H₄O₂
hope this helps!</span>
The molecular formula of the compound is C12H15O3 hence the molar mass of the compound is 207 g/mol.
We need to obtain the number of moles of carbon, hydrogen and oxygen in the compound;
Carbon = 24.91 g/44g/mol × 1 mole of carbon = 0.566 moles
Mass of carbon = 0.566 moles × 12 g/mol = 6.792 g
Number of moles of hydrogen = 6.522 g/18 g/mol × 2 moles = 0.725 moles
Mass of hydrogen = 0.725 moles × 1 g/mol = 0.725 g
Mass of oxygen = 10 - (6.792 g + 0.725 g) = 2.483 g
Number of moles of oxygen = 2.483 g/16 g/mol = 0.155 moles
Now we must divide through by the lowest number of moles;
C - 0.566/0.155 H - 0.725/0.155 O - 0.155/0.155
C - 4 H - 5 O - 1
The simplest formula is C4H5O Recall that the molar mass of the compound lies between 150.0 and 220.0 g/mol
4(12) + 5(1) + 16 = 69
Hence; n = 3 and the molecular formula of the compound is C12H15O3
The molar mass of the compound is; 12(12) + 15(1) + 3(16) = 207 g/mol
Learn more: brainly.com/question/15180604
Cs -137 has a half life of about 30 years. If 60 years pass, there is two half lives passed so 1/2 * 1/2= 1/4. Take 1/4 and multiply it with the mass given:
(1/4)*20mg=5mg left
