The answer would be 6 e-. This is becuase you are turning a charge of -4 into a +2. In order to do this, you transfer 4 electrons for a neutral charge, and an additional 2 for a charge of +2.
This makes a total charge of +2, and the total transferred electrons 6 e-
Answer:
The answer to your question is: Initial temperature of copper = 67.1°C
Explanation:
Data
mass Copper = 248 g
volume Water = 390 ml
T1 water = 22.6°C
T2 = 39.9°C
T1 copper = ?
Specific heat water = 1 cal/g°C
Specific heat copper = 0.092 cal/g°C
Formula copper water
Heat is negative for copper because it releases heat
- mCp(T2 - T1) = mCp(T2 - T1)
- (248)(39.9 - T1) = 390 (1)((39.9 - 22.6) Substitution
-9895.2 + 248T1 = 390(17.3) Simplification
-9895.2 + 248T1 = 6747
248 T1 = 6747 + 9895.2
248 T1 = 16642.2
T1 = 16642.2 / 248
T1 = 67.1 °C Result
The arrangement of molecules within the 3 phases of matter are shown in the picture.
For the solid, the molecules are packed closely together. They don't have much space to move, so they just practically vibrate. For the liquid, the molecules are relatively farther from each other. The liquid molecules can flow freely but not as much as the gases. In the gases, the molecules are very far from each other. They are very sensitive to slight changes of pressure, volume and temperature.
Answer:
23.34 %.
Explanation:
- The percentage of water must be calculated as a mass percent.
- We need to find the mass of water, and the total mass in one mole of the compound. For that we need to use the atomic masses of each element and take in consideration the number of atoms of each element in the formula unit.
- <em>Atomic masses of the elements:</em>
Cd: 112.411 g/mol, N: 14.0067 g/mol, O: 15.999 g/mol, and H: 1.008 g/mol.
- <em>Mass of the formula unit:</em>
Cd(NO₃)₂•4H₂O
mass of the formula unit = (At. mass of Cd) + 2(At. mass of N) + 10(At. mass of O) + 8(At. mass of H) = (112.411 g/mol) + 2(14.0067 g/mol) + 10(15.999 g/mol) + 8(1.008 g/mol) = 308.5 g/mol.
- <em> Mass of water in the formula unit:</em>
<em>mass of water</em> = (4 × 2 × 1.008 g/mol) + (4 × 15.999 g/mol) = 72.0 g/mol.
- <em>So, the percent of water in the compound = [mass of water / mass of the formula unit] × 100 = [(72.0 g/mol)/(308.5 g/mol)] × 100 = 23.34 %</em>
